posts: 25211
Data license: CC-BY
This data as json
| id | title | slug | type | status | content | archieml | archieml_update_statistics | published_at | updated_at | gdocSuccessorId | authors | excerpt | created_at_in_wordpress | updated_at_in_wordpress | featured_image | formattingOptions | markdown | wpApiSnapshot |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 25211 | How (and why) do estimates of terrorist deaths vary by source? | untitled-reusable-block-49 | wp_block | publish | <!-- wp:paragraph --> <p>In terrorism research, there are multiple databases available which attempt to record and detail terrorist incidents across the world. Some of the most well-known databases include <a href="https://library.duke.edu/data/sources/iterate"><em>International Terrorism</em>: <em>Attributes of Terrorist Events</em></a> (ITERATE); <a href="https://www.rand.org/nsrd/projects/terrorism-incidents.html"><em>RAND Database of Worldwide Terrorism Incidents</em></a> (RAND/RDWTI) and the <a href="https://www.start.umd.edu/gtd/"><em>Global Terrorism Database</em></a> (GTD).</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In our research on terrorism we present data from the Global Terrorism Database (GTD) for several reasons: it’s the most comprehensive in terms of the number of incidents covered; it is the most up-to-date; and is open-access, so widely used in academic research.{ref}Sheehan, I. S. (2012). <a href="https://link.springer.com/chapter/10.1007/978-1-4614-0953-3_2">Assessing and comparing data sources for terrorism research</a>. In <em>Evidence-based Counterterrorism Policy</em> (pp. 13-40). Springer, New York, NY.<br>{/ref} RAND, for example, only extends to the year 2009; and ITERATE is copyrighted, and not open-access for external users.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Nonetheless, estimates of the number of terrorist incidents and fatalities vary across these databases. Understanding why these differences exist is important for how this data is interpreted, and what we can conclude about the prevalence, causes and consequences of terrorism. Our understanding of the sources and frequency of terrorism can have a significant impact on many areas of society and policy, including immigration, counterterrorism efforts, and international relations.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In the chart we see a comparison between estimates of terrorism fatalities from the GTD and RAND datasets. Both sources go back as far as 1970 (RAND to 1968), with GTD extending to 2017 whilst RAND was discontinued in 2009.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Here we see large differences between the sources until the late 1990s/Millennium, after which they appear to more closely converge. Why is this the case?</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In a study published in the <em>Journal of Peace Research</em>, Sandler (2014) looked at the differences in methodology, estimates, and conclusions from the various terrorism databases in detail.{ref}Sandler, T. (2014). <a href="https://journals.sagepub.com/doi/full/10.1177/0022343313491277">The analytical study of terrorism: Taking stock</a>. <em>Journal of Peace Research</em>, <em>51</em>(2), 257-271.{/ref} Sandler found that the largest differentiator between the databases was whether they recorded domestic, transnational, or both forms of terrorism. Domestic terrorist incidents are those where the venue, perpetrators and victims are all from the same country: for example, a terrorist attack committed in the United States by a US citizen against victims from the US. If an attack involves more than one country – if the venue or victims of the attack are not the same country as the perpetrators – then it is classified as transnational.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The largest difference between the datasets is therefore that:</p> <!-- /wp:paragraph --> <!-- wp:list --> <ul><li>GTD includes both domestic and transnational incidents across its entire dataset from 1970 onwards;</li><li> RAND includes only transnational incidents until 1997; thereafter it included both domestic and transnational;</li><li>ITERATE includes only transnational incidents.</li></ul> <!-- /wp:list --> <!-- wp:paragraph --> <p>If we look again at the comparison of the GTD and RAND datasets in the chart below, this starts to make more sense. In the period prior to 1997, GTD consistently records more fatalities than RAND. During this time it included domestic incidents, whilst RAND did not. Since 1997 – when RAND also included domestic attacks – their figures have converged. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>A very clear example of this is seen if we look at figures in the United Kingdom. You can do this using the “Change country” button in the bottom-left of the interactive chart below. Here we see that during the 1970s and 1980s, RAND almost no fatalities compared to the GTD. During the 1970s and 1980s, terrorism in the UK – and Western Europe – was dominated by ‘The Troubles’ in Northern Ireland. Most deaths would have been classified as ‘domestic terrorism’, hence why they are included in the GTD but not the RAND figures.</p> <!-- /wp:paragraph --> <!-- wp:html --> <iframe src="https://ourworldindata.org/grapher/terrorism-deaths-rand-vs-gtd" style="width: 100%; height: 600px; border: 0px none;"></iframe> <!-- /wp:html --> <!-- wp:paragraph --> <p>Understanding the reasons for variations in the estimates of terrorist deaths may have a substantial impact on research and resource allocation. The root causes of transnational and domestic terrorism can be very different. The economic impacts – whether in the form of counterterrorism strategies; defence measures; or tourism impacts – can also vary significantly.{ref}Enders, W., Sandler, T., & Gaibulloev, K. (2011). <a href="https://pdfs.semanticscholar.org/d8ba/294036674fd60f09d1c2c0cfeee0dfae276a.pdf">Domestic versus transnational terrorism: Data, decomposition, and dynamics</a>. <em>Journal of Peace Research</em>, <em>48</em>(3), 319-337.{/ref} Understanding the prevalence and extent of both is therefore very important.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Beyond differences in the inclusion of domestic and transnational events, some differences in estimates exist. Most databases used in terrorism research are curated and maintained from media reports, whether print or digital media. Differences in the completeness and choices of media sources can lead to further variation between databases. This is because media sources do not always report, or accurately report terrorist events; this can lead to absent or conflicting estimates.{ref}Behlendorf, B., Belur, J., & Kumar, S. (2016). <a href="https://www.tandfonline.com/doi/abs/10.1080/1057610X.2016.1141004">Peering through the kaleidoscope: Variation and validity in data collection on terrorist attacks</a>. <em>Studies in Conflict & Terrorism</em>, <em>39</em>(7-8), 641-667.{/ref}</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The GTD notes this limitation in its <a href="https://www.start.umd.edu/gtd/using-gtd/">Data Collection Methodology</a>. It states that “<em>while the database developers attempt, to the best of their abilities, to corroborate each piece of information among multiple independent open sources, they make no further claims as to the veracity of this information”</em>, meaning that inconsistencies are entirely possible. Therefore, even when databases use the same definition of terrorism, the reported number of deaths depend on which media sources the database uses.</p> <!-- /wp:paragraph --> | {
"id": "wp-25211",
"slug": "untitled-reusable-block-49",
"content": {
"toc": [],
"body": [
{
"type": "text",
"value": [
{
"text": "In terrorism research, there are multiple databases available which attempt to record and detail terrorist incidents across the world. Some of the most well-known databases include ",
"spanType": "span-simple-text"
},
{
"url": "https://library.duke.edu/data/sources/iterate",
"children": [
{
"children": [
{
"text": "International Terrorism",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ": ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Attributes of Terrorist Events",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
}
],
"spanType": "span-link"
},
{
"text": " (ITERATE); ",
"spanType": "span-simple-text"
},
{
"url": "https://www.rand.org/nsrd/projects/terrorism-incidents.html",
"children": [
{
"children": [
{
"text": "RAND Database of Worldwide Terrorism Incidents",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
}
],
"spanType": "span-link"
},
{
"text": " (RAND/RDWTI) and the ",
"spanType": "span-simple-text"
},
{
"url": "https://www.start.umd.edu/gtd/",
"children": [
{
"children": [
{
"text": "Global Terrorism Database",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
}
],
"spanType": "span-link"
},
{
"text": " (GTD).",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "In our research on terrorism we present data from the Global Terrorism Database (GTD) for several reasons: it\u2019s the most comprehensive in terms of the number of incidents covered; it is the most up-to-date; and is open-access, so widely used in academic research.{ref}Sheehan, I. S. (2012). ",
"spanType": "span-simple-text"
},
{
"url": "https://link.springer.com/chapter/10.1007/978-1-4614-0953-3_2",
"children": [
{
"text": "Assessing and comparing data sources for terrorism research",
"spanType": "span-simple-text"
}
],
"spanType": "span-link"
},
{
"text": ". In ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Evidence-based Counterterrorism Policy",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": " (pp. 13-40). Springer, New York, NY.",
"spanType": "span-simple-text"
},
{
"spanType": "span-newline"
},
{
"text": "{/ref} RAND, for example, only extends to the year 2009; and ITERATE is copyrighted, and not open-access for external users.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "Nonetheless, estimates of the number of terrorist incidents and fatalities vary across these databases. Understanding why these differences exist is important for how this data is interpreted, and what we can conclude about the prevalence, causes and consequences of terrorism. Our understanding of the sources and frequency of terrorism can have a significant impact on many areas of society and policy, including immigration, counterterrorism efforts, and international relations.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "In the chart we see a comparison between estimates of terrorism fatalities from the GTD and RAND datasets. Both sources go back as far as 1970 (RAND to 1968), with GTD extending to 2017 whilst RAND was discontinued in 2009.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "Here we see large differences between the sources until the late 1990s/Millennium, after which they appear to more closely converge. Why is this the case?",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "In a study published in the ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Journal of Peace Research",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ", Sandler (2014) looked at the differences in methodology, estimates, and conclusions from the various terrorism databases in detail.{ref}Sandler, T. (2014). ",
"spanType": "span-simple-text"
},
{
"url": "https://journals.sagepub.com/doi/full/10.1177/0022343313491277",
"children": [
{
"text": "The analytical study of terrorism: Taking stock",
"spanType": "span-simple-text"
}
],
"spanType": "span-link"
},
{
"text": ". ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Journal of Peace Research",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ", ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "51",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": "(2), 257-271.{/ref} Sandler found that the largest differentiator between the databases was whether they recorded domestic, transnational, or both forms of terrorism. Domestic terrorist incidents are those where the venue, perpetrators and victims are all from the same country: for example, a terrorist attack committed in the United States by a US citizen against victims from the US. If an attack involves more than one country \u2013 if the venue or victims of the attack are not the same country as the perpetrators \u2013 then it is classified as transnational.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "The largest difference between the datasets is therefore that:",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "list",
"items": [
{
"type": "text",
"value": [
{
"text": "GTD includes both domestic and transnational incidents across its entire dataset from 1970 onwards;",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "\u00a0RAND includes only transnational incidents until 1997; thereafter it included both domestic and transnational;",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "ITERATE includes only transnational incidents.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "If we look again at the comparison of the GTD and RAND datasets in the chart below, this starts to make more sense. In the period prior to 1997, GTD consistently records more fatalities than RAND. During this time it included domestic incidents, whilst RAND did not. Since 1997 \u2013 when RAND also included domestic attacks \u2013 their figures have converged.\u00a0",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "A very clear example of this is seen if we look at figures in the United Kingdom. You can do this using the \u201cChange country\u201d button in the bottom-left of the interactive chart below. Here we see that during the 1970s and 1980s, RAND almost no fatalities compared to the GTD. During the 1970s and 1980s, terrorism in the UK \u2013 and Western Europe \u2013 was dominated by \u2018The Troubles\u2019 in Northern Ireland. Most deaths would have been classified as \u2018domestic terrorism\u2019, hence why they are included in the GTD but not the RAND figures.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"url": "https://ourworldindata.org/grapher/terrorism-deaths-rand-vs-gtd",
"type": "chart",
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "Understanding the reasons for variations in the estimates of terrorist deaths may have a substantial impact on research and resource allocation. The root causes of transnational and domestic terrorism can be very different. The economic impacts \u2013 whether in the form of counterterrorism strategies; defence measures; or tourism impacts \u2013 can also vary significantly.{ref}Enders, W., Sandler, T., & Gaibulloev, K. (2011). ",
"spanType": "span-simple-text"
},
{
"url": "https://pdfs.semanticscholar.org/d8ba/294036674fd60f09d1c2c0cfeee0dfae276a.pdf",
"children": [
{
"text": "Domestic versus transnational terrorism: Data, decomposition, and dynamics",
"spanType": "span-simple-text"
}
],
"spanType": "span-link"
},
{
"text": ". ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Journal of Peace Research",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ", ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "48",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": "(3), 319-337.{/ref} Understanding the prevalence and extent of both is therefore very important.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "Beyond differences in the inclusion of domestic and transnational events, some differences in estimates exist. Most databases used in terrorism research are curated and maintained from media reports, whether print or digital media. Differences in the completeness and choices of media sources can lead to further variation between databases. This is because media sources do not always report, or accurately report terrorist events; this can lead to absent or conflicting estimates.{ref}Behlendorf, B., Belur, J., & Kumar, S. (2016). ",
"spanType": "span-simple-text"
},
{
"url": "https://www.tandfonline.com/doi/abs/10.1080/1057610X.2016.1141004",
"children": [
{
"text": "Peering through the kaleidoscope: Variation and validity in data collection on terrorist attacks",
"spanType": "span-simple-text"
}
],
"spanType": "span-link"
},
{
"text": ". ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "Studies in Conflict & Terrorism",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ", ",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "39",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": "(7-8), 641-667.{/ref}",
"spanType": "span-simple-text"
}
],
"parseErrors": []
},
{
"type": "text",
"value": [
{
"text": "The GTD notes this limitation in its ",
"spanType": "span-simple-text"
},
{
"url": "https://www.start.umd.edu/gtd/using-gtd/",
"children": [
{
"text": "Data Collection Methodology",
"spanType": "span-simple-text"
}
],
"spanType": "span-link"
},
{
"text": ". It states that \u201c",
"spanType": "span-simple-text"
},
{
"children": [
{
"text": "while the database developers attempt, to the best of their abilities, to corroborate each piece of information among multiple independent open sources, they make no further claims as to the veracity of this information\u201d",
"spanType": "span-simple-text"
}
],
"spanType": "span-italic"
},
{
"text": ", meaning that inconsistencies are entirely possible. Therefore, even when databases use the same definition of terrorism, the reported number of deaths depend on which media sources the database uses.",
"spanType": "span-simple-text"
}
],
"parseErrors": []
}
],
"type": "article",
"title": "How (and why) do estimates of terrorist deaths vary by source?",
"authors": [
null
],
"dateline": "October 3, 2019",
"sidebar-toc": false,
"featured-image": ""
},
"createdAt": "2019-10-03T16:13:14.000Z",
"published": false,
"updatedAt": "2020-04-30T14:00:13.000Z",
"revisionId": null,
"publishedAt": "2019-10-03T15:13:03.000Z",
"relatedCharts": [],
"publicationContext": "listed"
} |
{
"errors": [
{
"name": "unexpected wp component tag",
"details": "Found unhandled wp:comment tag list"
}
],
"numBlocks": 14,
"numErrors": 1,
"wpTagCounts": {
"html": 1,
"list": 1,
"paragraph": 12
},
"htmlTagCounts": {
"p": 12,
"ul": 1,
"iframe": 1
}
} |
2019-10-03 15:13:03 | 2024-02-16 14:22:56 | [
null
] |
2019-10-03 16:13:14 | 2020-04-30 14:00:13 | {} |
In terrorism research, there are multiple databases available which attempt to record and detail terrorist incidents across the world. Some of the most well-known databases include [_International Terrorism_: _Attributes of Terrorist Events_](https://library.duke.edu/data/sources/iterate) (ITERATE); [_RAND Database of Worldwide Terrorism Incidents_](https://www.rand.org/nsrd/projects/terrorism-incidents.html) (RAND/RDWTI) and the [_Global Terrorism Database_](https://www.start.umd.edu/gtd/) (GTD). In our research on terrorism we present data from the Global Terrorism Database (GTD) for several reasons: it’s the most comprehensive in terms of the number of incidents covered; it is the most up-to-date; and is open-access, so widely used in academic research.{ref}Sheehan, I. S. (2012). [Assessing and comparing data sources for terrorism research](https://link.springer.com/chapter/10.1007/978-1-4614-0953-3_2). In _Evidence-based Counterterrorism Policy_ (pp. 13-40). Springer, New York, NY. {/ref} RAND, for example, only extends to the year 2009; and ITERATE is copyrighted, and not open-access for external users. Nonetheless, estimates of the number of terrorist incidents and fatalities vary across these databases. Understanding why these differences exist is important for how this data is interpreted, and what we can conclude about the prevalence, causes and consequences of terrorism. Our understanding of the sources and frequency of terrorism can have a significant impact on many areas of society and policy, including immigration, counterterrorism efforts, and international relations. In the chart we see a comparison between estimates of terrorism fatalities from the GTD and RAND datasets. Both sources go back as far as 1970 (RAND to 1968), with GTD extending to 2017 whilst RAND was discontinued in 2009. Here we see large differences between the sources until the late 1990s/Millennium, after which they appear to more closely converge. Why is this the case? In a study published in the _Journal of Peace Research_, Sandler (2014) looked at the differences in methodology, estimates, and conclusions from the various terrorism databases in detail.{ref}Sandler, T. (2014). [The analytical study of terrorism: Taking stock](https://journals.sagepub.com/doi/full/10.1177/0022343313491277). _Journal of Peace Research_, _51_(2), 257-271.{/ref} Sandler found that the largest differentiator between the databases was whether they recorded domestic, transnational, or both forms of terrorism. Domestic terrorist incidents are those where the venue, perpetrators and victims are all from the same country: for example, a terrorist attack committed in the United States by a US citizen against victims from the US. If an attack involves more than one country – if the venue or victims of the attack are not the same country as the perpetrators – then it is classified as transnational. The largest difference between the datasets is therefore that: * GTD includes both domestic and transnational incidents across its entire dataset from 1970 onwards; * RAND includes only transnational incidents until 1997; thereafter it included both domestic and transnational; * ITERATE includes only transnational incidents. If we look again at the comparison of the GTD and RAND datasets in the chart below, this starts to make more sense. In the period prior to 1997, GTD consistently records more fatalities than RAND. During this time it included domestic incidents, whilst RAND did not. Since 1997 – when RAND also included domestic attacks – their figures have converged. A very clear example of this is seen if we look at figures in the United Kingdom. You can do this using the “Change country” button in the bottom-left of the interactive chart below. Here we see that during the 1970s and 1980s, RAND almost no fatalities compared to the GTD. During the 1970s and 1980s, terrorism in the UK – and Western Europe – was dominated by ‘The Troubles’ in Northern Ireland. Most deaths would have been classified as ‘domestic terrorism’, hence why they are included in the GTD but not the RAND figures. <Chart url="https://ourworldindata.org/grapher/terrorism-deaths-rand-vs-gtd"/> Understanding the reasons for variations in the estimates of terrorist deaths may have a substantial impact on research and resource allocation. The root causes of transnational and domestic terrorism can be very different. The economic impacts – whether in the form of counterterrorism strategies; defence measures; or tourism impacts – can also vary significantly.{ref}Enders, W., Sandler, T., & Gaibulloev, K. (2011). [Domestic versus transnational terrorism: Data, decomposition, and dynamics](https://pdfs.semanticscholar.org/d8ba/294036674fd60f09d1c2c0cfeee0dfae276a.pdf). _Journal of Peace Research_, _48_(3), 319-337.{/ref} Understanding the prevalence and extent of both is therefore very important. Beyond differences in the inclusion of domestic and transnational events, some differences in estimates exist. Most databases used in terrorism research are curated and maintained from media reports, whether print or digital media. Differences in the completeness and choices of media sources can lead to further variation between databases. This is because media sources do not always report, or accurately report terrorist events; this can lead to absent or conflicting estimates.{ref}Behlendorf, B., Belur, J., & Kumar, S. (2016). [Peering through the kaleidoscope: Variation and validity in data collection on terrorist attacks](https://www.tandfonline.com/doi/abs/10.1080/1057610X.2016.1141004). _Studies in Conflict & Terrorism_, _39_(7-8), 641-667.{/ref} The GTD notes this limitation in its [Data Collection Methodology](https://www.start.umd.edu/gtd/using-gtd/). It states that “_while the database developers attempt, to the best of their abilities, to corroborate each piece of information among multiple independent open sources, they make no further claims as to the veracity of this information”_, meaning that inconsistencies are entirely possible. Therefore, even when databases use the same definition of terrorism, the reported number of deaths depend on which media sources the database uses. | {
"data": {
"wpBlock": {
"content": "\n<p>In terrorism research, there are multiple databases available which attempt to record and detail terrorist incidents across the world. Some of the most well-known databases include <a href=\"https://library.duke.edu/data/sources/iterate\"><em>International Terrorism</em>: <em>Attributes of Terrorist Events</em></a> (ITERATE); <a href=\"https://www.rand.org/nsrd/projects/terrorism-incidents.html\"><em>RAND Database of Worldwide Terrorism Incidents</em></a> (RAND/RDWTI) and the <a href=\"https://www.start.umd.edu/gtd/\"><em>Global Terrorism Database</em></a> (GTD).</p>\n\n\n\n<p>In our research on terrorism we present data from the Global Terrorism Database (GTD) for several reasons: it\u2019s the most comprehensive in terms of the number of incidents covered; it is the most up-to-date; and is open-access, so widely used in academic research.{ref}Sheehan, I. S. (2012). <a href=\"https://link.springer.com/chapter/10.1007/978-1-4614-0953-3_2\">Assessing and comparing data sources for terrorism research</a>. In <em>Evidence-based Counterterrorism Policy</em> (pp. 13-40). Springer, New York, NY.<br>{/ref} RAND, for example, only extends to the year 2009; and ITERATE is copyrighted, and not open-access for external users.</p>\n\n\n\n<p>Nonetheless, estimates of the number of terrorist incidents and fatalities vary across these databases. Understanding why these differences exist is important for how this data is interpreted, and what we can conclude about the prevalence, causes and consequences of terrorism. Our understanding of the sources and frequency of terrorism can have a significant impact on many areas of society and policy, including immigration, counterterrorism efforts, and international relations.</p>\n\n\n\n<p>In the chart we see a comparison between estimates of terrorism fatalities from the GTD and RAND datasets. Both sources go back as far as 1970 (RAND to 1968), with GTD extending to 2017 whilst RAND was discontinued in 2009.</p>\n\n\n\n<p>Here we see large differences between the sources until the late 1990s/Millennium, after which they appear to more closely converge. Why is this the case?</p>\n\n\n\n<p>In a study published in the <em>Journal of Peace Research</em>, Sandler (2014) looked at the differences in methodology, estimates, and conclusions from the various terrorism databases in detail.{ref}Sandler, T. (2014). <a href=\"https://journals.sagepub.com/doi/full/10.1177/0022343313491277\">The analytical study of terrorism: Taking stock</a>. <em>Journal of Peace Research</em>, <em>51</em>(2), 257-271.{/ref} Sandler found that the largest differentiator between the databases was whether they recorded domestic, transnational, or both forms of terrorism. Domestic terrorist incidents are those where the venue, perpetrators and victims are all from the same country: for example, a terrorist attack committed in the United States by a US citizen against victims from the US. If an attack involves more than one country \u2013 if the venue or victims of the attack are not the same country as the perpetrators \u2013 then it is classified as transnational.</p>\n\n\n\n<p>The largest difference between the datasets is therefore that:</p>\n\n\n\n<ul><li>GTD includes both domestic and transnational incidents across its entire dataset from 1970 onwards;</li><li> RAND includes only transnational incidents until 1997; thereafter it included both domestic and transnational;</li><li>ITERATE includes only transnational incidents.</li></ul>\n\n\n\n<p>If we look again at the comparison of the GTD and RAND datasets in the chart below, this starts to make more sense. In the period prior to 1997, GTD consistently records more fatalities than RAND. During this time it included domestic incidents, whilst RAND did not. Since 1997 \u2013 when RAND also included domestic attacks \u2013 their figures have converged. </p>\n\n\n\n<p>A very clear example of this is seen if we look at figures in the United Kingdom. You can do this using the \u201cChange country\u201d button in the bottom-left of the interactive chart below. Here we see that during the 1970s and 1980s, RAND almost no fatalities compared to the GTD. During the 1970s and 1980s, terrorism in the UK \u2013 and Western Europe \u2013 was dominated by \u2018The Troubles\u2019 in Northern Ireland. Most deaths would have been classified as \u2018domestic terrorism\u2019, hence why they are included in the GTD but not the RAND figures.</p>\n\n\n\n<iframe src=\"https://ourworldindata.org/grapher/terrorism-deaths-rand-vs-gtd\" style=\"width: 100%; height: 600px; border: 0px none;\"></iframe>\n\n\n\n<p>Understanding the reasons for variations in the estimates of terrorist deaths may have a substantial impact on research and resource allocation. The root causes of transnational and domestic terrorism can be very different. The economic impacts \u2013 whether in the form of counterterrorism strategies; defence measures; or tourism impacts \u2013 can also vary significantly.{ref}Enders, W., Sandler, T., & Gaibulloev, K. (2011). <a href=\"https://pdfs.semanticscholar.org/d8ba/294036674fd60f09d1c2c0cfeee0dfae276a.pdf\">Domestic versus transnational terrorism: Data, decomposition, and dynamics</a>. <em>Journal of Peace Research</em>, <em>48</em>(3), 319-337.{/ref} Understanding the prevalence and extent of both is therefore very important.</p>\n\n\n\n<p>Beyond differences in the inclusion of domestic and transnational events, some differences in estimates exist. Most databases used in terrorism research are curated and maintained from media reports, whether print or digital media. Differences in the completeness and choices of media sources can lead to further variation between databases. This is because media sources do not always report, or accurately report terrorist events; this can lead to absent or conflicting estimates.{ref}Behlendorf, B., Belur, J., & Kumar, S. (2016). <a href=\"https://www.tandfonline.com/doi/abs/10.1080/1057610X.2016.1141004\">Peering through the kaleidoscope: Variation and validity in data collection on terrorist attacks</a>. <em>Studies in Conflict & Terrorism</em>, <em>39</em>(7-8), 641-667.{/ref}</p>\n\n\n\n<p>The GTD notes this limitation in its <a href=\"https://www.start.umd.edu/gtd/using-gtd/\">Data Collection Methodology</a>. It states that \u201c<em>while the database developers attempt, to the best of their abilities, to corroborate each piece of information among multiple independent open sources, they make no further claims as to the veracity of this information\u201d</em>, meaning that inconsistencies are entirely possible. Therefore, even when databases use the same definition of terrorism, the reported number of deaths depend on which media sources the database uses.</p>\n"
}
},
"extensions": {
"debug": [
{
"type": "DEBUG_LOGS_INACTIVE",
"message": "GraphQL Debug logging is not active. To see debug logs, GRAPHQL_DEBUG must be enabled."
}
]
}
} |