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<p>This page is maintained in Google Docs: <a href="https://owid.cloud/admin/gdocs/1RvMWl3OpP6zrygM49jcvI6SotoWWq5er14gLBnPLxUg/preview">https://owid.cloud/admin/gdocs/1RvMWl3OpP6zrygM49jcvI6SotoWWq5er14gLBnPLxUg/preview</a></p>
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<h3>Explore more of our work on Animal Welfare</h3>
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<p>THIS PAGE ONLY EXISTS TO GET ECONOMIC INEQUALITY LISTED IN THE BY-TOPIC MENU.</p>
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<p>The inequality page is now in Google Docs: https://docs.google.com/document/d/1yzOrFd6uWvrAl2oFB3S67oOSbhgL1ffPHxjAqS7i-4w/edit</p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of inequality indicators measured according to two different definitions of income obtained from different sources.</p>
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<ul><li>Data from the World Inequality Database relates to inequality before taxes and benefits.</li><li>Data from the World Bank relates to either income after taxes and benefits or consumption, depending on the country and year.</li></ul>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators from different sources:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of indicators obtained from the World Bank Poverty and Inequality Platform. Depending on the country and year, the data relates to income measured after taxes and benefits, or consumption, per capita.</p>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of indicators obtained from the Luxemburg Income Study dataset, related to income before and after taxes and benefits.</p>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of indicators obtained from the World Inequality Database, related to income before and after taxes and benefits.</p>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of indicators obtained from different sources.</p>
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<ul><li>Data from the World Bank relates to either income per capita after taxes and benefits or consumption, depending on the country and year.</li><li>Data from the World Inequality Database and Luxembourg Income Study relate to income before and after taxes and benefits.</li></ul>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<h3>About this data</h3>
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<p>This data explorer provides a range of poverty indicators obtained from different sources.</p>
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<ul><li>Data from the World Bank relates to either income per capita after taxes and benefits or consumption per capita, depending on the country and year.</li><li>Data from the Luxembourg Income Study relates to income after taxes and benefits per capita.</li></ul>
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<p>Further information about the definitions and methods behind this data can be found in the article below, where you can also explore and compare a much broader range of indicators:</p>
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<p><a href="https://ourworldindata.org/owid-data-collection-inequality-and-poverty">OWID Data Collection: Inequality and Poverty</a></p>
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<p>Mental illnesses are diagnosed by health professionals using manuals, which describe their symptoms, their context, and how they differ from similar conditions.</p>
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<p>How are these manuals used? How are major mental illnesses described and diagnosed?</p>
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<p>This article summarizes the major mental illnesses in the ICD-11 manual, the official worldwide classification.</p>
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<p>Each section includes a summary of how the condition is medically diagnosed, a description of the symptoms, and other conditions that must be ruled out before making a diagnosis.</p>
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<p>If you want to read the full criteria for diagnosing mental illnesses according to the ICD-11, you can find them <a href="https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f334423054">here</a>.</p>
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<h3>What are the different manuals in use?</h3>
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<p>Diagnosing a mental illness begins when people see a doctor or psychiatrist.</p>
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<p>It can be difficult to define mental illnesses because they are conditions of the mind: they are diagnosed according to people's symptoms and behavior. This means they can be subjective – they are dependent partly on people’s comfort seeing a doctor or psychiatrist, the training and experiences of healthcare professionals, and other cultural factors.</p>
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<p>Two manuals are commonly used by doctors and psychiatrists to diagnose mental illnesses: the <strong>International Classification of Diseases (ICD)</strong> and the <strong>Diagnostic and Statistical Manual of Mental Disorders (DSM)</strong>.&nbsp;</p>
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<p>There are differences in how they are used.</p>
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<p>In many countries, many people with mental illnesses go undiagnosed, meaning mental health is given less attention and support than it deserves. Even for those diagnosed, treatment can be of poor quality, if they receive it at all.{ref}Alonso, J., Liu, Z., Evans‐Lacko, S., Sadikova, E., Sampson, N., Chatterji, S., ... &amp; WHO World Mental Health Survey Collaborators. (2018). Treatment gap for anxiety disorders is global: Results of the World Mental Health Surveys in 21 countries. Depression and anxiety, 35(3), 195-208. <a href="https://doi.org/10.1002/da.22711">https://doi.org/10.1002/da.22711</a> {/ref}</p>
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<p>To reduce the burden of mental illnesses, the world needs reliable data, which includes the number of people that face mental illnesses, how and when they occur, and the effectiveness of treatments.</p>
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<h3>How are mental illnesses defined?</h3>
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<p>Defining mental illnesses is complex. They are diagnosed based on people’s psychological symptoms and behavior rather than biomarkers, brain scans, or blood tests. This makes them more subjective – they are dependent on whether people share their symptoms and the way doctors diagnose them.</p>
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<p>Mental illnesses are formally defined according to the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual of Mental Disorders (DSM). The ICD is used internationally by healthcare professionals, while the DSM is primarily used by psychiatrists in the United States.{ref}Kupfer, D. J., Regier, D. A., &amp; Kuhl, E. A. (2008). On the road to DSM-V and ICD-11. European Archives of Psychiatry and Clinical Neuroscience, 258(S5), 2–6. <a href="https://doi.org/10.1007/s00406-008-5002-6">https://doi.org/10.1007/s00406-008-5002-6</a…

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<p>This page is now maintained in Google Docs: <a href="https://owid.cloud/admin/gdocs/1RvMWl3OpP6zrygM49jcvI6SotoWWq5er14gLBnPLxUg/preview">https://owid.cloud/admin/gdocs/1RvMWl3OpP6zrygM49jcvI6SotoWWq5er14gLBnPLxUg/preview</a></p>
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<p>This page is now maintained in Google Docs: https://owid.cloud/admin/gdocs/195wtinOB2zsiGevmvUfAGPZv4NrG4jY_vpib49e5gt4/preview</p>
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<p>Seasonal flu is a contagious illness caused by the influenza virus. It kills around 400,000 people from respiratory disease on average each year. In large pandemics, when new strains have evolved, the death toll has been much higher.&nbsp;</p>
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<p>Yet, data on the flu is limited. With better testing, countries could improve their response to flu epidemics. It could help to rapidly identify new strains, detect epidemics early, and design better-matched vaccines to target flu strains circulating in the population.</p>
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<p>This page therefore shows estimates of deaths during seasonal flu epidemics, …

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<p>Food insecurity <a href="https://www.fao.org/hunger/en/">is defined by</a> the Food and Agriculture Organization (FAO) of the United Nations as the “situation when people lack secure access to sufficient amounts of safe and nutritious food for normal growth and development and an active and healthy life.”</p>
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<p>The chart below shows the share of the population that is ‘severely food insecure'. Let’s look at what this means, and how this is measured.</p>
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<h3>What is food insecurity and how is it measured?</h3>
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<p>Food insecurity is one of the major causes of poor nutrition.</p>
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<p>Food insecurity can be caused by several factors: food might be physically unavailable in a particular country or region; it can be <a href="http://ourworldindata.org/food-prices">unaffordable</a> even if it is available to buy; or there might be an unequal distribution of food between household members.</p>
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<p>Food insecurity is measured by the FAO using its Food Insecurity Experience Scale (FIES) global reference scale.</p>
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<p>Food insecurity can be based on how having <em>enough</em> food (the quantity) or having inadequate <em>quality</em> and diversity of food. Someone might get enough food to meet their…

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<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/technological-change" target="_blank" rel="noopener">Technological Change</a></strong>.</p>
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<p>Technologies that follow Wright’s Law get cheaper at a consistent rate, as the cumulative production of that technology increases.&nbsp;</p>
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<p>The best way to explain what this means is to look at a concrete example.</p>
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<h4>Solar technology: an example of a technology that follows Wright’s Law</h4>
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<p>The time series in the chart shows the deployment of solar panels on the horizontal axis and the price of solar panels on the vertical axis. The orange line that describes the relationship between these two metrics over time is called the <em>learning curve</em> of that technology.&nbsp;</p>
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<p>As the cumulative installed capacity increased, the price of solar <em>declined</em> <em>exponentially</em>. Solar technology is a prime example. For more than four decades, the price of solar panels declined by 20% with each doubling of global cumulative capacity.</p>
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<p>The fact that both metrics changed exponentially can be nicely seen in this chart because both axes are logarithmic. On a logarithmic axis, a measure that declines exponentially <a href="https://blog.datawrapper.de/weeklychart-logscale/">follows a straight line</a>.&nbsp;</p>
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<p>That more production leads to falling prices is not surprising – such ‘economies of scale’ are found in the production of many goods. If you are already making one pizza, making a second one isn’t that much…

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<h2>Why we provide this Influenza Data Explorer</h2>
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<p><strong>With this Flu Explorer, we aim to provide a helpful resource for epidemiologists, infectious disease researchers, and public health experts to understand the global spread of the influenza virus.</strong></p>
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<p>While influenza is not always at the forefront of the public's mind, it is a significant cause of death globally — it causes <a href="https://pubmed.ncbi.nlm.nih.gov/31673337/">400,000 respiratory deaths</a> each year on average.</p>
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<p>Additionally, it is considered <a href="https://doi.org/10.1038/s12276-021-00603-0">one of the leading candidates</a> for a future pandemic. To detect these risks early, the world must closely monitor the situation. Accessible data must be available for those who can help understand and manage the potential threats.</p>
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<p>This Flu Data Explorer differs from our widely-used infectious diseases projects, such as the <a href="https://ourworldindata.org/explorers/coronavirus-data-explorer">COVID-19 Explorer</a> and the <a href="https://ourworldindata.org/explorers/monkeypox">Mpox Explorer</a>. These tools are designed for a broad audience. Unfortunately, flu data is incomplete in many ways, making it harder to communicate. <strong>This tool is therefore designed for users with pre-existing knowledge to navigate effectively the complex data published by the World Health Organization.</strong></p>
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<p>The explorer also highlights the significant gaps in influenza data. It is an important reminder of the need to improve data collection and reporting.</p>
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<p>Before navigating this Explorer, we recommend reading the <a href="https://ourworldindata.org/influenza#key-insights-on-influenza">key insights</a> on our Influenza page; the…

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<p>Population growth is one of the most important topics we cover at <em>Our World in Data</em>.</p>
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<p>For most of human history, the global population was<em> </em>a tiny fraction of what it is today. Over the last few centuries, the human population has gone through an extraordinary change. In 1800, there were one billion people. Today there are more than 8 billion of us.</p>
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<p>But after a period of very fast population growth, demographers expect the world population to peak by the end of this century.</p>
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<p>On this page, you will find all of our …

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<p>Age standardization can be helpful when comparing rates of health outcomes (for example, deaths from cancer) between populations, because age can be a significant risk factor for many diseases.</p>
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<p>Since age structure varies between countries and in the same country over time, this adjustment allows us to see how mortality and morbidity vary without age differences.&nbsp;</p>
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<p>Age standardization involves adjusting the observed rates of a particular outcome to a “standard population” with a specific age structure.</p>
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<h4>Why is it helpful to standardize health metrics for age?</h4>
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<p>The proportion of people in different age groups in a country is called its "age structure." Countries across the world have significant differences in age structure. For example, only <a href="https://ourworldindata.org/grapher/population-by-broad-age-group?stackMode=relative&amp;country=~UGA">2% of the population of Uganda</a> is older than 65, against <a href="https://ourworldindata.org/grapher/population-by-broad-age-group?stackMode=relative&amp;country=~JPN">30% in Japan</a>.</p>
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<p>But many diseases or health outcomes occur more frequently as people get older: for example, cancers, heart disease, or dementia.</p>
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<p>This difference in age structure means that a condition that affects older people will tend to occur more frequently in the Japanese population than in the Ugandan population, simply because of the higher proportion of older people in the country.</p>
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<p>Standardizing the data for age can tell us how a health condition compares between Japan and Uganda if there were no differences in the age structure of the two countries.</p>
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<p>One of the most pressing environmental problems over the last century has been the depletion of the ozone layer. But what is the ozone layer, and why does it matter?</p>
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<p>Ozone is a gas present naturally within Earth’s atmosphere. It is formed of three oxygen atoms (giving it the chemical formula O<sub>3</sub>). Its structure makes it unstable: it can be easily formed and broken down through interaction with other compounds.</p>
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<p>Ozone is most highly concentrated at two very different altitudes in the atmosphere: near the surface, and high in the atmosphere (in the stratosphere). Its function is very different in these two zones.</p>
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<h3>‘Good ozone’ and ‘bad ozone’</h3>
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<p>Ozone close to the surface is called tropospheric ozone, and it is often referred to as ‘<strong>bad ozone</strong>’. Ozone concentrations are lower in the troposphere than in the stratosphere.</p>
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<p>We can see this in the diagram.&nbsp;</p>
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<p>However, ozone concentrations close to the Earth’s surface can be temporarily and locally higher, because of emissions from motor vehicle exhausts, industrial processes, electric utilities, and chemical solvents. Ground-level ozone is a local air pollutant, and can negatively impact human health. Breathing ozone is particularly harmful to the young, elderly, and people with underlying respiratory problems.</p>
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<p>This is very different from ozone high in the atmosphere: stratospheric ozone. It’s referred to as ‘<strong>good ozone</strong>’.</p>
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<p>As shown in the diagram, ozone concentrations are higher in th…

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<p>The observation that the number of transistors on computer chips doubles approximately every two years is known as Moore’s Law.</p>
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<p>Moore’s Law is not a law of nature, but an observation of a long-term trend in how technology is changing.</p>
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<p>The law was first described by Gordon E. Moore, the co-founder of Intel, in 1965.{ref}The original paper is Gordon E. Moore (1965) – <a href="https://web.archive.org/web/20211221191553/http://www.monolithic3d.com/uploads/6/0/5/5/6055488/gordon_moore_1965_article.pdf">Cramming more components onto integrated circuits</a>. In Electronics, Volume 38, Number 8, April 19, 1965.{/ref} </p>
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<p>The chart shows Moore’s original graph that he drew in 1965 to describe this regularity. At the time, he had only a handful of data points. Note that he drew it on a logarithmic scale, and remember that a straight line on a log-axis means that the&nbsp;<em>growth rate</em> is constant and it is therefore showing the exponential growth of the number of transistors.</p>
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<p>However, he hypothesized that this relationship would continue at a similar rate: “There is no reason to believe it will not remain constant for at least 10 years”.{ref}Quoted from Gordon E. Moore (1965) – <a href="https://web.archive.org/web/20211221191553/http://www.monolithic3d.com/uploads/6/0/5/5/6055488/gordon_moore_1965_article.pdf">Cramming more components onto integrated circuits</a>. In Electronics, Volume 38, Number 8, April 19, 1965.{/ref}</p>
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<p>Johns Hopkins University has been at the forefront of collecting and reporting data on confirmed COVID-19 cases and deaths since the outbreak began in 2020. However, it <a href="https://github.com/CSSEGISandData/COVID-19/issues/6577">recently announced</a> that it would stop updating its data on 10 March 2023.</p>
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<p>Our team at Our World in Data recognizes the importance of up-to-date data on the pandemic. We will switch our primary source to <a href="https://covid19.who.int/data">the World Health Organization (WHO)</a>, which updates its dataset weekly.</p>
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<p>To keep this data consistent over time, we will replace the entire time series with WHO data on 8 March 2023.</p>
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<p>Our goal is to continue providing the most complete and timely data on the pandemic, and relying on the WHO data is the best way to achieve this.</p>
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<p>This change will be seamless for our users. The URL of all our charts and the variable names in our dataset will remain the same.</p>
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<p><a href="https://github.com/owid/covid-19-data/tree/master/public/data">All other COVID-19 datasets</a> we maintain will remain unchanged.</p>
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<p>An archive of the last version (8 March 2023) of our dataset based on data from Johns Hopkins University is available for download <a href="https://covid.ourworldindata.org/data/owid-covid-data-old.csv">here</a> (CSV file, 69 Mo).</p>
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<p>We want to take this opportunity to thank the team at Johns Hopkins for their crucial work since the beginning of the pandemic. Their efforts have been invaluable in helping us understand the impact of this virus across the world.</p>
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<p>For each topic, we work to provide the best metrics to understand it. What metrics are 'best' will often depend on our specific questions. Overall, a metric we provide will fit many of the following criteria:</p>
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<ul><li><strong>It covers large parts of the world. </strong>True to our name, we seek metrics which cover as much of the world as possible. Only then can they help us understand global differences and changes.</li></ul>
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<p></p>
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<ul><li><strong>It covers a lot of time. </strong>This means both that the measure goes as far back in time as possible, and that it is as recent as possible. It then can help us understand both historical and very recent developments.</li></ul>
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<p></p>
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<ul><li><strong>It is comparable across time and space</strong>. This means that we prefer metrics that can be compared across years and countries. This allows us to evaluate whether countries are making progress or falling behind, and how countries are doing relative to another.</li></ul>
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<p></p>
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<ul><li><strong>It captures what we are trying to measure</strong>. This means that the metric does not give an incomplete or misleading answer to the question we have. For example, an inadequate measure for whether a country is a democracy is the share of the population that voted. Looking only at voter turnout ignores whether citizens had more than one choice at the ballot box. And at the same time, it inadvertently considers citizens that were coerced to vote.</li></ul>
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<p></p>
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<ul><li><strong>It is reliable.</strong> This means that the metric is consistent, i.e. it captures the phenomenon similarly when measured repeatedly, and therefore is preci…

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<p>We cover a topic if we believe it helps our readers understand one or several of the world’s largest problems. More specifically, this means that a topic will fit many of the following criteria:</p>
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<p></p>
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<ul><li><strong>It affects many countries and people.</strong> This can mean that it concerns every person, such as <a href="https://ourworldindata.org/health-meta">health</a>. It can mean that it affects many people in all countries, such as <a href="https://ourworldindata.org/poverty">poverty</a>. Or it can mean that it affects many people in fewer countries, such as <a href="https://ourworldindata.org/malaria">malaria</a>.</li></ul>
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<p></p>
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<ul><li><strong>It comes with great costs or benefits. </strong>The costs or benefits can be direct, and shorten people’s lives or mean they lead happier lives. An example is the <a href="https://ourworldindata.org/coronavirus">COVID-19 pandemic</a>, which has immediately affected people’s well-being. But the costs or benefits can also be indirect, and worsen or alleviate other problems. An example is <a href="https://ourworldindata.org/agricultural-production">agricultural production</a>, which affects many people’s access to nutrition.</li></ul>
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<p></p>
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<ul><li><strong>It poses significant risks.</strong> This means that it may not impose great costs at the moment, but may do so in the future. An example is <a href="https://ourworldindata.org/nuclear-weapons">nuclear weapons</a>, which have not been used in decades but whose use would be devastating.</li></ul>
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<p></p>
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<ul><li><strong>It will remain important, or become more important in the future.</strong> <a href="https://ourworldindata.org/poverty">Poverty</a> is a…

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<p>This page is dedicated to the research why people are optimistic or pessimistic about certain things and how this is influenced by human nature,&nbsp;the media, and social circumstances.</p>
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<p>We are interested in this topic also because it is closely linked to <a rel="noopener noreferrer" href="https://ourworldindata.org/about/" target="_blank">our motivation</a> for publishing&nbsp;Our World in Data. We face big global problems, but living conditions around the world have improved in important ways; fewer people are dying of disease, conflict and famine; more of us are receiving a basic education; the world is becoming more democratic; we live longer and lead healthier lives. </p>
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<p>Why is that we – especially those in the developed world&nbsp;– often have a negative view on how the world has changed over the last decades and centuries? Why we&nbsp;are so pessimistic about our collective future?</p>
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<h2>Human nature and pessimism</h2>
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<h3>Individual optimism and social pessimism</h3>
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<p>It is a peculiar empirical phenomenon that while people tend to be optimistic about their own future, they can at the same time be deeply pessimistic about the future of their nation or the world. Tali Sharot, associate professor of psychology at UCL, has popularised the idea of an innate optimism bias built into the human brain.{ref}Sharot, Tali. <em>The Optimism Bias: A Tour of the Irrationally Positive Brain</em>. New York: Pantheon Books, 2011.<br><br>Sharot, Tali. <em>The Science of Optimism Why We're Hard-wired for Hope</em>. New York: Ted Conferences, 2012.{/ref}</p>
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<p> That is, we tend to be optimistic rather than realistic when considering our individual future. If you were to ask newlywed couples to estimate the prob…

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<p>Now in GDoc: https://owid.cloud/admin/gdocs/1Ame1LHwda2O45NasOLFDDbWY3HWaTAToB0FbmYdLVwI/preview</p>
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<p>On <em>Our World in Data</em>, we present thousands of metrics on hundreds of topics.</p>
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<p>But there are many more topics that we could work on, and metrics we could present. How do we choose them?</p>
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<p></p>
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<h4>How do we choose which topics to cover?</h4>
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<p>We cover a topic if we believe it helps our readers understand one or several of the world’s largest problems. More specifically, this means that a topic will fit many of the following criteria:</p>
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<p></p>
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<ul><li><strong>It affects many countries and people.</strong> This can mean that it concerns every person, such as <a href="https://ourworldindata.org/health-meta">health</a>. It can mean that it affects many people in all countries, such as <a href="https://ourworldindata.org/poverty">poverty</a>. Or it can mean that it affects many people in fewer countries, such as <a href="https://ourworldindata.org/malaria">malaria</a>.</li></ul>
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<p></p>
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<ul><li><strong>It comes with great costs or benefits. </strong>The costs or benefits can be direct, and shorten people’s lives or mean they lead happier lives. An example is the <a href="https://ourworldindata.org/coronavirus">COVID-19 pandemic</a>, which has immediately affected people’s well-being. But the costs or benefits can also be indirect, and worsen or alleviate other problems. An example is <a href="https://ourworldindata.org/agricultural-production">agricultural production</a>, which affects many people’s access to nutrition.</li></ul>
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<p></p>
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<ul><li><strong>It poses significant risks.</strong> This means that it may not impose great costs …

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<p>The International Union for Conservation of Nature (IUCN) reports that tens of thousands of species are <a href="https://ourworldindata.org/grapher/number-species-threatened">threatened with extinction</a>.</p>
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<p>But what does it mean for a species to be ‘threatened with extinction’? How do researchers evaluate extinction risk?</p>
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<p>The <a href="https://www.iucnredlist.org/">IUCN <em>Red List of Threatened Species</em></a> is regarded as the definitive source of extinction risk. Every year, the IUCN publishes its latest assessment of the status of each evaluated species.</p>
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<p>In this article, we look at how species are categorized and assessed for their extinction risk.</p>
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<h3>The 9 categories of extinction risk</h3>
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<p>Each species is assessed against a standardized list of criteria.{ref}Here we use the term ‘species’ to talk about different groups of organisms. This is the main level that wildlife is evaluated for extinction risk. But, the IUCN also uses the broader term ‘taxon’ which applies at the species level or sub-species level. This means that the framework can be applied to evaluate extinction risk at multiple levels.{/ref} Based on these answers, a species is assigned to one of <strong>nine categories</strong>:</p>
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<ul><li>Not Evaluated (NE)</li><li>Data Deficient (DD)</li><li>Least Concern (LC)</li><li>Near Threatened (NT)</li><li>Vulnerable (VU)</li><li>Endangered (EN)</li><li>Critically Endangered (CR)</li><li>Extinct in the Wild (EW)</li><li>Extinct (EX)<br></li></ul>
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<p>How these categories relate to each other is shown in the visualization.</p>
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<p>Richer people tend to spend more money on food.</p>
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<p>We see this relationship when we look at data on food expenditure from across the world.</p>
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<p>In the chart you see food expenditure plotted against total consumer expenditure per person. Total consumer expenditure is any personal expenditure on goods and services.</p>
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<p>On the y-axis, we have the average amount of money spent on food per person, in countries across the world.{ref}This data comes from the United States Department of Agriculture (USDA) Economic Research Service, which estimates this for countries where available market data is sufficient.{/ref} This measures money spent on food consumed at home – from stores and supermarkets. The source <em>does not </em>include food eaten out-of-home, from restaurants and cafes (however, that would be useful data to have). Tobacco and alcoholic beverages are also excluded.</p>
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<p>On the x-axis, we have a measure of prosperity, total expenditure. Expenditure tells us how much disposable income people have to spend on goods and services such as food, housing, education, health, and leisure activities. It’s important to ensure that we can afford all of the essentials that give us a high and comfortable standard of living.</p>
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<p>Countries which are poor – and where therefore people’s expenditure is very low – can be found, richer countries are further towards the right. This is shown on a log axis by default, but you can change it to a linear scale on the interactive chart.</p>
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<p>Both metrics are measured in US dollars per person per year.</p>
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<p>What we see is a strong po…

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<p>Measuring the state of human rights across the world helps us understand the extent to which people have fundamental personal and civil rights and freedoms.</p>
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<p>But it can be challenging to measure how well-protected these human rights are.. People do not always agree on what rights are fundamental. These rights — such as whether people are free to voice their opinions — are difficult to define and assess. The judgement of experts is to some degree subjective. They may disagree about a specific characteristic or how several characteristics can be reduced into a single measure.</p>
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<p>How do researchers address these challenges and measure how much people’s human rights are protected?</p>
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<h4><strong>What are the Varieties of Democracy project?</strong></h4>
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<p>In some of our work on democracy, we rely on data published by the <a href="https://www.v-dem.net/vdemds.html">Varieties of Democracy (V-Dem) project</a>.{ref}Coppedge, Michael, John Gerring, Carl Henrik Knutsen, Staffan I. Lindberg, Jan Teorell, Nazifa Alizada, David Altman, Michael Bernhard, Agnes Cornell, M. Steven Fish, Lisa Gastaldi, Haakon Gjerløw, Adam Glynn, Sandra Grahn, Allen Hicken, Garry Hindle, Nina Ilchenko, Katrin Kinzelbach, Joshua Krusell, Kyle L. Marquardt, Kelly McMann, Valeriya Mechkova, Juraj Medzihorsky, Pamela Paxton, Daniel Pemstein, Josefine Pernes, Oskar Ryden, Johannes von Römer, Brigitte Seim, Rachel Sigman, Svend-Erik Skaaning, Jeffrey Staton, Aksel Sundström, Eitan Tzelgov, Yi-ting Wang, Tore Wig, Steven Wilson and Daniel Ziblatt. 2022.<a href="https://scholar.google.com/scholar?hl=en&amp;as_sdt=0%2C5&amp;q=Coppedge%2C+Michael%2C+John+Gerring%2C+Carl+Henrik+Knutsen%2C+Staffan+I.+Lindberg%2C+Jan+Teorell%2C+Nazifa+Alizada%2C+David+Altman%2C+Michael+Bernhard%2C+Agnes+Cornell%2C+M.+Steven+Fish%2C+Lisa+Gastaldi%2C+Ha…

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<p>Humans have transformed the mammal kingdom.</p>
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<p>A diverse range of mammals once roamed the planet. This changed quickly and dramatically with the arrival of humans. Since then, wild land mammal biomass <a href="https://ourworldindata.org/wild-mammal-decline">has declined</a> by an estimated 85%.</p>
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<p>Humans are now the dominant species.</p>
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<p>We see this when we look at the distribution of mammals across the world today.</p>
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<p>There are various ways that we could look at mammal species: we could compare them based on the number of individuals: their <em>abundance</em>. This tends to favor very small animals with large populations and doesn’t necessarily give us an idea of how dominant different species are.</p>
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<p>Instead, ecologists often look at a different metric: biomass. This not only takes into account the <em>number</em> of animals but also factors in their size. Each animal is measured in tonnes of carbon, the fundamental building block of life.{ref}To calculate the biomass of a taxonomic group, the researchers multiplied the carbon stock for a single organism by the number of individuals in that group. In humans, for example, they calculate the average carbon quantity of a person and multiply by the human population. If you want to quickly estimate your carbon biomass: calculate 15% of your weight.{/ref} Biomass gives us a measure of the total biological productivity of an ecosystem. It also gives more weight to larger animals at higher levels of the ecological ‘pyramid’: these rely on well-functioning bases below them.</p>
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<p>Let’s then look at the breakdown of the global mammal kingdom in 2015. This data…

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<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/artificial-intelligence" target="_blank" rel="noopener">Artificial Intelligence</a></strong>.</p>
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<p>Technology can change the world in ways that are unimaginable, until they happen. Switching on an electric light would have been unimaginable for our medieval ancestors. In their childhood, our grandparents would have struggled to imagine a world connected by smartphones and the Internet.</p>
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<p>Similarly, it is hard for us to imagine the arrival of all those technologies that will fundamentally change the world we are used to.</p>
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<p>We can remind ourselves that our own future might look very different from the world today by looking back at how rapidly technology has changed our world in the past. That’s what this article is about.&nbsp;</p>
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<p>One insight I take away from this long-term perspective is how unusual our time is. Technological change was <em>extremely</em> slow in the past – the technologies that our ancestors got used to in their childhood were still central to their lives in their old age. In stark contrast to those days, we live in a time of extraordinarily fast technological change. For recent generations, it was common for technologies that were unimaginable in their youth to become common later in life.&nbsp;</p>
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<h4>The long-run perspective on technological change</h4>
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<p>The big visualization offers a long-term perspective on the history of technology.{ref}T…

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<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/artificial-intelligence" target="_blank" rel="noopener">Artificial Intelligence</a></strong>.</p>
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<p>Artificial intelligence (AI) that surpasses our own intelligence sounds like the stuff from science-fiction books or films. What do experts in the field of AI research think about such scenarios? Do they dismiss these ideas as fantasy, or are they taking such prospects seriously?</p>
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<p>A human-level AI would be a machine, or a network of machines, capable of carrying out the same range of tasks that we humans are capable of. It would be a machine that is “able to learn to do anything that a human can do”, as Norvig and Russell put it in their textbook on AI.{ref}Peter Norvig and Stuart Russell (2021) – Artificial Intelligence: A Modern Approach. Fourth edition. Published by Pearson.{/ref}</p>
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<p>It would be able to choose actions that allow the machine to achieve its goals and then carry out those actions. It would be able to do the work of a translator, a doctor, an illustrator, a teacher, a therapist, a driver, or the work of an investor.&nbsp;</p>
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<p>In recent years, several research teams contacted AI experts and asked them about their expectations for the future of machine intelligence. Such expert surveys are one of the pieces of information that we can rely on to form an idea of what the future of AI might look like.</p>
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<p>The chart shows the answers of 352 experts. This is from the most recent study by Katja Grace and her co…

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<div class="blog-info">
<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/artificial-intelligence" target="_blank" rel="noopener">Artificial Intelligence</a></strong>.</p>
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<p>Artificial intelligence (AI) technology has steadily become more powerful over the course of the last decades and in recent years it has entered our world in many different domains. In a companion article – <a href="https://ourworldindata.org/brief-history-of-ai">the brief history of artificial intelligence</a> – I document this development.</p>
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<p>This was achieved despite having relatively few resources. Until recently, investments in terms of capital and scientific efforts were small. In this article I highlight that this has very much changed in recent years. Corporate investment has increased and the scientific field has grown in size.</p>
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<p>Given how rapidly AI developed in the past, despite the limited resources, this should make us expect AI technology to continue to become more powerful in the coming decades.&nbsp;</p>
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<h4>Investments into AI</h4>
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<p>The first chart looks at corporate investment over time.{ref}It is not obvious how to adjust a time-series of AI investments for inflation, and we debated it at some length within the team.&nbsp;</p>
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<p>Reporting it in nominal prices (as some do) means it makes little sense to compare observations across time and is therefore not very helpful. To make comparisons over time possible one has to take into account that prices change.</p>
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<p>It would be straightforward to adjust th…

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<div class="blog-info">
<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/artificial-intelligence" target="_blank" rel="noopener">Artificial Intelligence</a></strong>.</p>
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<p>To see what the future might look like it is often helpful to study our history. This is what I will do in this article. I retrace the brief history of computers and artificial intelligence to see what we can expect for the future.</p>
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<h4>How did we get here?</h4>
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<p>How rapidly the world has changed becomes clear by how even quite recent computer technology feels ancient to us today. Mobile phones in the ‘90s were big bricks with tiny green displays. Two decades before that the main storage for computers was punch cards.&nbsp;</p>
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<p>In a short period computers evolved so quickly and became such an integral part of our daily lives that it is easy to forget how recent this technology is. The first digital computers were only invented about eight decades ago, as the timeline shows.</p>
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<p>Since the early days of this history, some computer scientists have striv…

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<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>This article draws on data and research discussed in our entry on <strong><a href="https://ourworldindata.org/artificial-intelligence" target="_blank" rel="noopener">Artificial Intelligence</a></strong>.</p>
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<p>Why should you care about the development of artificial intelligence?</p>
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<p>Think about what the alternative would look like. If you and the wider public do not get informed and engaged, then we leave it to a few entrepreneurs and engineers to decide how this technology will transform our world.</p>
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<p>That is the status quo. This small number of people at a few tech firms directly working on artificial intelligence (AI) do understand how extraordinarily powerful this technology is <a href="https://ourworldindata.org/brief-history-of-ai">becoming</a>. If the rest of society does not become engaged, then it will be this small elite who decides how this technology will change our lives.</p>
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<p>To change this status quo, I want to answer three questions in this article: Why is it hard to take the prospect of a world transformed by AI seriously? How can we imagine such a world? And what is at stake as this technology becomes more powerful?</p>
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<h4>Why is it hard to take the prospect of a world transformed by artificial intelligence seriously?</h4>
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<p>In some way, it should be obvious how technology can fundamentally transform the world. We just have to look at how much the world has already changed. If you could invite a family of hunter-gatherers from 20,000 years ago on your next flight, they would be pretty surprised. Technology has changed our world already, so we should expec…

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<p>Elephants are the world’s largest living land animals, weighing in at<a href="https://d2ouvy59p0dg6k.cloudfront.net/downloads/african_elephant_factsheet2007w.pdf"> up to 7.5 tonnes</a>.{ref}African elephants are typically bigger than the Asian species. African elephants can weigh up to 7.5 tonnes; Asian elephants<a href="http://wwf.panda.org/knowledge_hub/endangered_species/elephants/asian_elephants/"> up to 5 tonnes</a>.{/ref} </p>
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<p>Their size has made them a prime target for poaching. History has shown us that it is usually the largest mammals that are most at risk from human hunting. Elephants are no different. We hunt them for their meat, their trunks, and their lucrative tusks.</p>
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<p>There are around 450,000 elephants in the world. But this is a tiny fraction of how many there used to be.</p>
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<p>In this article we look at the state of elephant populations, and how these populations have changed over time.</p>
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<h4>State of elephant populations today</h4>
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<p>There are two species of elephant: the African (with the official name <em>Loxodonta africana</em>) and the Asian (<em>Elephas maximus</em>) elephant.&nbsp;</p>
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<p>If you want to tell the difference between them, look at their ears: the African elephant has much bigger ears, very similar in shape to the African continent; the Asian elephant has much smaller, rounded ears.{ref}Elephants dissipate heat via their ears, and so use them for temperature regulation. The reason that African elephants have larger ears is that they live in warmer climates and therefore need to dissipate more heat.{/ref} Their tusks are also a usef…

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<p>There have been five big mass extinctions in Earth's history – these are called the "Big Five". Understanding the reasons and timelines of these events is important to understand the speed and scale of species extinctions today.</p>
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<p>When and why did these mass extinction events happen?</p>
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<h3>What is a mass extinction?</h3>
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<p>First, we must be clear on what we mean by "mass extinction". Extinctions are a normal part of evolution: they occur naturally and periodically over time.{ref}Jablonski D (1986) <a href="https://science.sciencemag.org/content/231/4734/129.abstract?casa_token=EoFixpArJnsAAAAA:R4ejNN9Ccy8BjYWiJJMfWUToj6qJSJFQ8jWGiMsL_x2OoBRfsrBdze0p8n6kvYdps25LiL8hcRKwrcy9">Mass and background extinctions: the alternation of macroevolutionary regimes</a>. <em>Science</em> 231:129–133{/ref} </p>
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<p>There’s a natural background rate to the timing and frequency of extinctions: 10% of species are lost every million years, 30% every 10 million years, and 65% every 100 million years.{ref}Raup DM (1991) <a href="https://scholar.google.com/scholar?hl=en&amp;as_sdt=0%2C5&amp;q=A+Kill+Curve+For+Phanerozoic+Marine+Species+David+M.+Raup+Paleobiology+Vol.+17%2C+No.+1+%28Winter%2C+1991%29%2C+pp.+37-48+%2812+pages%29&amp;btnG=">A kill curve for Phanerozoic marine species</a>. <em>Paleobiology</em>. 17:37–48.{/ref} It would be wrong to assume that species going extinct is out of line with what we would expect. Evolution occurs through the balance of <em>extinction</em> – the end of species – and <em>speciation</em> – the creation of new ones.</p>
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<p>Extinctions occur periodically at what we would call the "background rate". We can therefore identify periods of history when extinctions were happening much faster than this background rate – this would tell us that …

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<p>How many species do we share our planet with? It's such a basic and fundamental question to understanding the world around us. </p>
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<p>It's almost unthinkable that we would not know this number or at least have a good estimate. But the truth is that it's a question that continues to escape the world's taxonomists.</p>
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<p>An important distinction is <strong>how many species we have identified and described</strong> and how many species there actually are. We've only identified a small fraction of the world's species, so these numbers are very different.</p>
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<h3>How many species have we <em>described</em>?</h3>
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<p>Before we look at estimates of how many species there are in total, we should first ask the question of how many species we <em>know that we know. </em>Species that we have identified and named.</p>
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<p>The <a href="https://www.iucnredlist.org/resources/summary-statistics">IUCN Red List</a> tracks the number of described species and updates this figure annually based on the latest work of taxonomists. In 2021, it listed 2.13 million species on the planet. In the chart, we see the breakdown across a range of taxonomic groups – 1.05 million insects, over 11,000 birds, over 11,000 reptiles, and over 6,000 mammals.</p>
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<p>These figures – particularly for lesser-known groups such as plants or fungi – might be a bit too high. This is because some described species are synonyms – the description of already-known species, simply given a separate name.{ref}Costello, M. J., May, R. M., &amp; Stork, N. E. (2013). Can we name Earth's species before they go extinct?.&nbsp;Science,&nbsp;339(6118), 413-416.{/ref} There is…

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<p>Humans have had such a profound impact on the planet’s ecosystems and climate that Earth might be defined by a new geological epoch: the Anthropocene (where “anthropo” means “human”). </p>
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<p>Some think this new epoch should start during the Industrial Revolution, and some at the advent of agriculture 10,000 to 15,000 years ago. This feeds into the popular notion that environmental destruction is a recent phenomenon.</p>
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<p>The lives of our ancestors are often romanticized. Many think they lived in balance with nature, unlike modern society where we fight against it. But when we look at the evidence of human impacts over millennia, it's hard to see how this was true.</p>
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<p>Our ancient ancestors contributed to the extinction of many of the world's largest mammals ('megafauna'). This was during an event known as the Quaternary megafauna extinction (QME).</p>
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<p>The extent of these extinctions across continents is shown in the chart. Between 52,000 and 9,000 BCE, more than 178 species of the world’s largest mammals were killed off. These were mammals heavier than 44 kilograms, ranging from mammals the size of sheep to mammoths.</p>
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<p>There is strong evidence to suggest that these were largely driven by humans – we look at this in more detail later.</p>
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<p>Africa was the least hard-hit, losing only 21% of its megafauna. Humans evolved in Africa, and hominins had already interacted with mammals for a long time. The same is also likely to be true across Eurasia, where 35% of megafauna were lost. But Australia, North America, and South America were particularly hard-hit; very soon after humans…

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<p>Weighing in at over 150 tonnes, Blue Whales are the <a href="https://en.wikipedia.org/wiki/Blue_whale">largest animal</a> to have lived on Earth. But their size hasn’t protected them from human exploitation. In fact, their size made them an incredibly valuable source of oil, meat and blubber. This fat gave us a rich fuel for energy and many other industrial uses.</p>
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<p>Human hunting has resulted in a massive decline in global whale populations. Some have been pushed to the brink of extinction. But, as we will see, a combination of technological change, economic incentives and international policies have brought global whaling to very low levels. While some populations are still very small, we have been successful in preserving these beautiful animals.</p>
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<h4>Early whaling in the United States</h4>
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<p>Whaling is a practice that dates back to Medieval times; fortunately at low levels, meaning this early practice had little impact on whale populations.{ref}Birnie, P. W. (1989). <a href="https://www.jstor.org/stable/24883418">International legal issues in the management and protection of the whale: a review of four decades of experience</a>. <em>Natural Resources Journal</em>, <em>29</em>(4), 903-934.{/ref}</p>
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<p>While global whaling was a feature of the 1900s, the peak of whaling in the United States was a century earlier. In the 18th and 19th centuries, whaling was a key industry in the US. </p>
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<p>Although the uses of whale oil later diversified, Americans mainly used it for lighting. Whale oil was used for the lighting of not only homes but also outdoor street lighting, lighthouses and miner’s headlamps – a range of uses t…

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<p>The largest mammals are at the greatest risk of extinction. This has been the case since the arrival of humans, and is still true today.</p>
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<p>Weighing in at several tonnes, rhinos are some of the world’s largest mammals.{ref}The <a rel="noreferrer noopener" href="https://web.archive.org/web/20230130123018/https://rhinos.org/wp-content/uploads/2020/10/IRF_factsheet_digital_Mar2020-1.pdf" target="_blank">average mass of rhinos</a> vary by species and sex. Male White and Indian rhinos can weigh up to 2700 kilograms; at the other end, Sumatran rhinos have a lower range of around 600 kilograms.{/ref} With extravagant prices for rhino horns and body parts, they’re also one of the most threatened: three of the five rhino species are ‘critically endangered’. </p>
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<p>In this article we take a look at the status of rhino populations today, and whether they are in decline or on the path to recovery. They offer us both stories of concern and reasons for optimism.</p>
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<h3>State of rhino populations today</h3>
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<p>There are five species of rhino. Africa is home to the White and Black Rhino. The remaining three – the Sumatran, Javan and Indian – exist in Asia.&nbsp;</p>
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<p>Some of these species have dangerously low population levels.</p>
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<p>The Sumatran and the Javan Rhino can now only be found in Indonesia. They are Critically Endangered with less than 100 individuals left in the wild. The Black Rhino, despite having a population in the thousands, is also Critically Endangered. It experienced a rapid decline over the 20th century as we will see later.</p>
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<p>The Indian (Greater One-Horned) offers us an important success story; it has seen a sig…

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<p>Artificial intelligence (AI) systems already greatly impact our lives — they increasingly shape what we see, believe, and do. Based on the steady advances in AI technology and the large recent <a href="/ai-investments">increases</a> in investment, we should expect AI technology to become even more powerful and impactful in the following years and decades. </p>
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<p>It is <a href="/technology-long-run">easy to underestimate</a> how much the world can change within a lifetime, so it is worth taking seriously what those who work on AI expect for the future. Many AI experts <a href="/ai-timelines">believe</a> there is a real chance that human-level artificial intelligence will be developed within the following decades, and some think it will exist much sooner. </p>
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<p>How such powerful AI systems are built and used will be very important for the future of our world …

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<p>The Living Planet Index (LPI) is a measure of biodiversity that is often misinterpreted. In my <a href="https://ourworldindata.org/living-planet-index-decline">accompanying article</a> on the Living Planet Index, I describe these misinterpretations in detail, and what it actually tells us about the state of global biodiversity.</p>
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<p>In this short page I answer some commonly-asked questions about this measure of biodiversity.</p>
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<h3>What does the Living Planet Index (LPI) measure?</h3>
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<p>The Living Planet Index (LPI) provides a measure of wildlife <em>abundance</em>. It measures the <em>average</em> decline in population size since 1970 across a wide range of species.{ref}WWF (2022)&nbsp;<em>Living Planet Report 2022 – Building a nature-positive society</em>. Almond, R.E.A., Grooten, M., Juffe Bignoli, D. &amp; Petersen, T. (Eds). WWF, Gland, Switzerland.{/ref}</p>
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<h3>What does the Living Planet Index (LPI) <em>not</em> measure?</h3>
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<p>The Living Planet Index does not measure:</p>
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<ul><li>Number of species lost</li><li>Number of populations or individuals that have been lost</li><li>Number or percentage of species or populations that are declining</li><li>Number of extinctions</li></ul>
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<h3>What types of species are included?</h3>
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<p>The LPI only includes data from vertebrate populations. This includes mammals, birds, reptiles, amphibians, and fish. Taxonomic groups including insects, corals, fungi, and plants are not included.</p>
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<h3>How many species does it cover? What is the geographical range of this coverage?</h3>
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<p>The Living Planet Index (LPI) is a measure of biodiversity that is often misinterpreted. In my <a href="https://ourworldindata.org/living-planet-index-decline">accompanying article</a> on the Living Planet Index, I describe these misinterpretations in detail, and what it actually tells us about the state of global biodiversity.</p>
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<p>In brief, the LPI measures the <em>average</em> change in the size of studied animal populations. It does not tell us the total change in animal populations; the share of populations that have been lost; or anything about extinctions.</p>
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<p>The main headline result of the 2022 Living Planet Index report was that studied animal populations globally <a href="https://ourworldindata.org/grapher/global-living-planet-index">have seen</a> an <em>average</em> decline of 69% between 1970 and 2018.{ref}WWF (2022)&nbsp;<em>Living Planet Report 2022 – Building a nature-positive society</em>. Almond, R.E.A., Grooten, M., Juffe Bignoli, D. &amp; Petersen, T. (Eds). WWF, Gland, Switzerland.{/ref}</p>
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<p>But these results vary a lot from region to region.</p>
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<p>In the chart we see the LPI given by region. This is measured relative to 1970, which is assigned a value of one.</p>
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<p><strong>Latin America and the Caribbean</strong></p>
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<p>Latin America and the Caribbean have seen the most severe decline of any region. It experienced an average decline of 94% across its studied populations. When we think about the changes in some of the leading drivers of biodiversity loss, we should not be surprised that Latin America has been badly affected.</p>
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<p>In recent deca…

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<h3>Data sources and methodological differences</h3>
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<p>We source the data for the Global Health Explorer from three main sources:&nbsp;</p>
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<ul><li>World Health Organization’s Global Health Estimates</li><li>World Health Organization’s Global Health Observatory</li><li>Institute of Health Metrics and Evaluation’s Global Burden of Disease Study</li></ul>
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<h4>Global Health Estimates (WHO GHE)</h4>
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<p>The Global Health Estimates are primarily calculated using cause-of-death statistics that are reported to the WHO by individual countries.&nbsp;</p>
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<p>These vital registration (VR) statistics are submitted to the WHO Mortality Database on an annual basis by country, year, cause, age and sex. This data is included in the Global Health Estimates if it meets criteria assessing completeness and quality. Since many countries don't meet these criteria, the GHE does not incorporate VR statistics for every country.</p>
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<p>There are a number of specialist WHO groups and UN agencies that collect topic or disease-specific data. The dataset on HIV and AIDS – collected and published by UN AIDS – is one example of this. The estimates based on the VR data are compared to the data from specialist WHO groups and UN agencies and adjustments are made if necessary.&nbsp;</p>
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<p>Where the VR data is not usable and there is no other nationally representative cause of death data, then the World Health Organization adopts the IHME’s Global Burden of Disease data to fill these gaps. Full details on how the WHO’s Global Health Estimates are calculated are available <a href="https://web.archive.org/web/20221028092355/https://cdn.who.int/media/docs/default-source/gho-documents/global-health-estimates/…

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<p>Measuring the state of democracy across the world helps us understand the extent to which people have political rights and freedoms.</p>
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<p>But measuring democracy comes with many challenges. People do not always agree on what characteristics define a democracy. These characteristics — such as whether an election was free and fair — are difficult to define and assess. The judgment of experts is to some degree subjective. They may disagree about a specific characteristic or how something as complex as a political system can be reduced into a single measure.</p>
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<p>How do researchers address these challenges and measure democracy?</p>
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<h4><strong>What is the Varieties of Democracy (V-Dem) project?</strong></h4>
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<p>In some of our work on democracy, we rely on data published by the <a href="https://www.v-dem.net/vdemds.html">Varieties of Democracy (V-Dem) project</a>.{ref}Coppedge, Michael, John Gerring, Carl Henrik Knutsen, Staffan I. Lindberg, Jan Teorell, David Altman, Michael Bernhard, Agnes Cornell, M. Steven Fish, Lisa Gastaldi, Haakon Gjerløw, Adam Glynn, Ana Good God, Sandra Grahn, Allen Hicken, Katrin Kinzelbach, Joshua Krusell, Kyle L. Marquardt, Kelly McMann, Valeriya Mechkova, Juraj Medzihorsky, Natalia Natsika, Anja Neundorf, Pamela Paxton, Daniel Pemstein, Josefine Pernes, Oskar Rydén, Johannes von Römer, Brigitte Seim, Rachel Sigman, Svend-Erik Skaaning, Jeffrey Staton, Aksel Sundström, Eitan Tzelgov, Yi-ting Wang, Tore Wig, Steven Wilson and Daniel Ziblatt. 2023. <a href="https://scholar.google.com/scholar?hl=en&amp;as_sdt=0%2C5&amp;q=Coppedge%2C+Michael%2C+John+Gerring%2C+Carl+Henrik+Knutsen%2C+Staffan+I.+Lindberg%2C+Jan+Teorell%2C+David+Altman%2C+Michael+Bernhard%2C+Agnes+Cornell%2C+M.+Stev…

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<h4>Authors of this work</h4>
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<p>This redesign project was built by Joe Hasell, Matthew Conlen, Marwa Boukarim, Matthieu Bergel, Ike Saunders, Daniel Bachler, Pablo Arriagada, and Max Roser.</p>
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<p>At <em>Our World in Data</em>, we present data and research in a number of ways: as individual charts, data explorers that allow users to switch between metrics, technical articles that explain what particular metrics mean, and articles that explain what the data tells us about the world to make progress.</p>
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<p>We have more than 3,000 interactive charts spanning hundreds of topics.</p>
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<p>One of our biggest challenges has been bringing all of this data and research together in a way that users can navigate easily. People should be able to quickly find exactly what they’re looking for. And be able to find it again when they come back.</p>
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<p>To help solve this challenge, over the past year, our product and engineering teams have been working on the design of a new format for collecting and presenting all our data, research, and writing on particular topics.</p>
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<p>We’ve now published the first example of this redesign for one topic – <a href="https://ourworldindata.org/poverty" data-type="URL" data-id="https://ourworldindata.org/poverty">Poverty</a>.</p>
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<p>We plan to progressively roll this design out across the other topics on our site in the next year.</p>
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<h4>The World Bank has updated its poverty and inequality data</h4>
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<p>The data in this article uses a previous release of the World Bank's poverty and inequality data in which incomes are expressed in 2011 international-$.</p>
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<p>The World Bank has since updated its methods, and now measures incomes in 2017 international-$. As part of this change, the International Poverty Line used to measure extreme poverty has also been updated: from $1.90 (in 2011 prices) to $2.15 (in 2017 prices).</p>
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<p>This has had little effect on our overall understanding of poverty and inequality around the world. But because of the change of units, many of the figures mentioned in this article will differ from the latest World Bank figures.</p>
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<p>Read more about the World Bank's updated methodology</p>
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<p>Globally, seasonal influenza kills 400,000 people from respiratory disease each year on average. During large flu pandemics, when influenza strains evolved substantially, the death toll was even higher.</p>
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<p>But the risk of dying from influenza has declined substantially over time from improvements in sanitation, healthcare, and vaccination.&nbsp;</p>
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<p>People born in 1940 had around a third of the risk of dying from influenza as those born in 1900 –&nbsp;even when they reached the same age. This decline continued, and those born in 1980 have a risk of half that of those born in 1940.</p>
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<p>Influenza still remains a large burden around the world, because of an aging population and a lack of access to healthcare and sanitation in many countries.&nbsp;</p>
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<p>In this article, we look into these developments in detail: how many people die from seasonal influenza and how this has changed over time.&nbsp;</p>
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<p>We will also look at which factors increase the risk of dying from the flu and understand why, in some years, influenza has led to large pandemics that caused millions of deaths. This knowledge can inform us about the risks of influenza in the future.</p>
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<h4>How many people die from seasonal influenza?</h4>
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<p>The true cost of burning fossil fuels is not reflected in their market price. People <a href="https://ourworldindata.org/cheap-renewables-growth">often compare</a> the <em>monetary price</em> of fossil fuels to low-carbon alternatives such as renewables or nuclear energy. But these comparisons do not capture each option’s social impact, even in a purely economic sense.</p>
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<p>Burning fossil fuels drives <a href="http://ourworldindata.org/climate-change">climate change</a>. The impacts of climate change come at a cost – these impacts are already happening.</p>
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<p>They also cause local air pollution, which <a href="https://ourworldindata.org/data-review-air-pollution-deaths">kills millions</a> every year and has negative health impacts for many more.</p>
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<p>One way to address this is to put a price on carbon. The purpose of setting a carbon price is to capture some of these external costs in the market.</p>
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<p>My colleague, Max Roser, wrote a detailed case for a carbon price <a href="https://ourworldindata.org/carbon-price"><strong>here</strong></a>.</p>
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<p>Putting a price on carbon achieves a couple of things. First, it makes more polluting fuels, products, and services more expensive. Burning coal becomes <a href="https://ourworldindata.org/safest-sources-of-energy">much more expensive</a> than using solar energy. Beef gets <a href="https://ourworldindata.org/explorers/food-footprints">more expensive</a> relative to tofu or meat alternatives. It makes the ‘cleaner’ option less expensive.</p>
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<p>Second, it means it’s those who emit greenhouse gases that pay for it.</p>
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<p>There are a few policies through which countries can put a price on carbon:</p>
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<p>Most of the plastic that enters the oceans from land <a href="https://ourworldindata.org/ocean-plastics">comes from</a> rivers in Asia.{ref}It’s estimated that around 70% to 80% of the plastic in the ocean comes from land. The other 20% to 30% comes from marine sources, such as fishing nets and lines.<br><br>In some parts of the ocean, the contribution of marine sources is higher. For example, it’s estimated that up to 52% of the plastic mass in the ‘Great Pacific Garbage Patch’ is plastic lines, ropes, and fishing nets.<br><br>Li, W. C., Tse, H. F., &amp; Fok, L. (2016). <a href="https://www.sciencedirect.com/science/article/pii/S0048969716310154">Plastic waste in the marine environment: A review of sources, occurrence and effects</a>. <em>Science of the Total Environment</em>, 566, 333-349.</p>
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<p>Lebreton, L., Slat, B., Ferrari, F., Sainte-Rose, B., Aitken, J., Marthouse, R., … &amp; Noble, K. (2018). <a href="https://www.nature.com/articles/s41598-018-22939-w">Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic</a>. <em>Scientific Reports</em>, 8(1), 4666.{/ref} More than 80% of it.{ref}One of the most recent estimates from Meijer et al. (2021) estimates that 81% of plastic waste that is emitted to the ocean comes from Asia.</p>
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<p>An earlier study, by Lebreton et al. (2017), estimated a similar figure of 86% coming from Asian rivers.</p>
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<p>Meijer, J.J.L, Emmerik, T., Ent, R., Schmidt, C., Lebreton, L. (2021). <a href="https://advances.sciencemag.org/content/7/18/eaaz5803">More than 1000 rivers account for 80% of global riverine plastic emissions into the ocean</a>. <em>Science Advances</em>.</p>
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<p>Lebreton, L. C., Van der Zwet, J., Damsteeg, J. W., Slat, B., Andrady, A., &amp; Reisser, J. (2017). <a href="https://www.nature.com/articles/ncomms15611">River plastic emissions to…

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<p>To track progress towards its goal of <a href="https://sdg-tracker.org/no-poverty#1.1">eradicating extreme poverty by 2030</a>, the UN relies on World Bank estimates of the share of the world population that fall below the International Poverty Line.</p>
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<p>In September 2022, the figure at which this poverty line is set shifted from $1.90 to $2.15. This reflects a change in the units in which the World Bank expresses its poverty and inequality data – from international dollars given in <em>2011</em> prices to international dollars given in <em>2017</em> prices.</p>
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<p>In this article we consider what the World Bank’s revised methodology means for our understanding of global poverty. We then also explain the updated methodology: what international dollars are, what the change to 2017 prices mean, and how this change affects the International Poverty Line and the World Bank’s poverty estimates.</p>
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<h3><strong>How does the updated International Poverty Line affect our understanding of global poverty?</strong></h3>
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<p>The crucial fact to know about the World Bank’s updated International Poverty Line is that, whilst the number has risen – from $1.90 to $2.15 per day – in terms of the goods and services that it affords, the value is broadly the same.</p>
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<p>This is because the units in which the old and new figures are counted have changed: the $1.90 figure was expressed in 2011 international-$, and the new figure of $2.15 is expressed in 2017 international-$.</p>
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<p>Below we explain in much more detail what international dollars are and what the change in base year means. But broadly speaking, the difference in the two units reflects inflation over time: Because prices have gone up, one 2017 international-$ buys a…

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<p>How do reusable blocks work?</p>
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<p>I don't know</p>
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<p>Our World in Data presents the data and research to make progress against the world’s largest problems.<br>Find all our data and research on poverty on our <strong><a href="https://ourworldindata.org/poverty" target="_blank" rel="noopener">Poverty</a></strong> topic page.
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<p>One of the most important trends that we can learn from the work of social scientists and historians is that extreme poverty, as measured by people's level of consumption, has fallen considerably around the world in the <a href="https://ourworldindata.org/grapher/share-in-poverty-relative-to-different-poverty-thresholds-historical?country=~OWID_WRL">last two centuries</a>. But why should we care? Is it not the case that poor people might have less consumption but enjoy their lives just as much—or even more—than people with much higher consumption levels?</p>
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<p>One way to find out is to simply ask. Subjective views are an important way of measuring welfare.</p>
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<p>This is what the <em>Gallup Organization</em> did. The <a href="https://www.gallup.com/analytics/232838/world-poll.aspx" target="_blank" rel="noreferrer noopener">Gallup World Poll</a> asked people around the world what they thought about their standard of living—not only about their income. The following chart compares the answers of people in different countries with the average income in&nbsp;those countries. It shows that, broadly speaking, people living in poorer countries&nbsp;tend to be less satisfied with their living standards.</p>
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<h6>Dissatisfaction with standard of living vs GDP per capita{ref} GDP per capita data from the World Bank. Survey data on the satisfaction with living standards is from the <a href="http://www.gallup.com/services/170945/world-poll.aspx">Gallup World Poll</a>. The idea for this chart is taken from Deaton (2010)…

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<p>All the data included in this explorer is available to download <a href="https://github.com/owid/poverty-data">in GitHub</a>, alongside a range of other poverty and inequality metrics.</p>
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<h3>About this data</h3>
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<h4>Where is this data sourced from?</h4>
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<p>This data explorer is collated and adapted from the World Bank’s <a href="https://pip.worldbank.org/home">Poverty and Inequality Platform</a> (PIP).</p>
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<p>The World Bank’s PIP data is a large collection of household surveys where steps have been taken by the World Bank to harmonize definitions and methods across countries and over time.</p>
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<h4>About the comparability of household surveys</h4>
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<p>There is no global survey of incomes. To understand how incomes across the world compare, researchers need to rely on available national surveys.</p>
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<p>Such surveys are partly designed with cross-country comparability in mind, but because the surveys reflect the circumstances and priorities of individual countries at the time of the survey, there are some important differences.</p>
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<p><strong>Income vs expenditure surveys</strong></p>
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<p>One important issue is that the survey data included within the <a href="https://pip.worldbank.org/home">PIP</a> database tends to measure people’s income in high-income countries, and people’s consumption expenditure in poorer countries.</p>
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<p>The two concepts are closely related: the income of a household equals their consumption plus any saving, or minus any borrowing or spending out of savings.&nbsp;</p>
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<p><a href="https://ourworldindata.org/democratic-rights">Many more people than in the past have democratic rights</a>. But now there is growing concern that this progress is currently being partially undone.{ref}See for example:</p>
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<p>Lührmann, Anna, and Staffan Lindberg. 2019. A third wave of autocratization is here: what is new about it? Democratization 26(7): 1095-1113.</p>
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<p>Haggard, Stephan, and Robert Kaufman. 2021. The Anatomy of Democratic Backsliding. Journal of Democracy 32(4): 27-41.{/ref} Is this true? Has the world become less democratic recently?</p>
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<p>This article shows that the <a href="https://ourworldindata.org/democracies-measurement">leading approaches</a> to measuring democracy indicate that this is true: the world has become less democratic in recent years.</p>
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<p>Democracy is in decline, whether we look at big changes in the number of democracies and the people living in them; at small changes in the extent of democratic rights; or at medium-sized changes in the number of, and people living in, countries that are autocratizing.{ref}I use ‘autocratizing’ and ‘becoming less democratic’ as synonyms.{/ref}</p>
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<p>The extent of this decline is substantial, but it is also uncertain and limited. We can see it clearly across democracy metrics: the world has fallen from all-time democratic highs to a level similar to earlier decades. But the extent of this decline depends on which democracy measure we use. And it is limited in the sense that the world remains much more democratic than it was even half a century ago.</p>
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<p>Finally, the recent democratic decline is precedented, and past declines were reversed. The world underwent phases of autocratization in the 1930s an…

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<h2>Explore more of our work on Plastic Pollution</h2>
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<h3>Explore more of our work on Air Pollution</h3>
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<h3>Explore more of our work on the Environmental Impacts of Food</h3>
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<p>200 years ago, everyone lacked democratic rights. Now, <a href="https://ourworldindata.org/democratic-rights">billions of people have them</a>.</p>
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<p>But there are still large differences in the degree to which citizens enjoy political rights: most clearly between democracies and non-democracies, but also <em>within</em> these broad political regimes.</p>
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<p>To understand the extent of people’s political rights, we shouldn’t only look at whether a country is classified as a democracy or not. We should also look at smaller differences in <em>how democratic</em> countries are.</p>
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<p>How democratic have countries been across the world? And how big are the differences between them?</p>
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<p>To answer these questions, we need information on countries’ political systems over recent centuries.</p>
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<h4>How can researchers measure how democratic a country is?</h4>
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<p>Measuring how democratic countries are comes with many challenges. People do not always agree on what characteristics define a democracy. Its characteristics — such as whether an election was free and fair — are difficult to assess. The assessments of experts are to some degree subjective and they may disagree; either about a specific characteristic, or how several characteristics can be reduced into a single measure of democracy.</p>
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<p>​​Because of these difficulties, classifying political systems is unavoidably controversial. I have written more about how researchers deal with the challenges of measuring democracy <a href="https://ourworldindata.org/democracies-measurement">in another article</a>.</p>
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<p>The source we show here is the electoral democracy index fr…

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<h4>Explore more of our work on <em>Our World in Data</em></h4>
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