From Isolation to Radicalization: Anti-Muslim Hostility and Support for ISIS in the West. Published in the American Political Science Review. [Paper] [Ungated] [Appendix] [Replication]

What explains online radicalization and support for ISIS in the West? Over the past few years, thousands of individuals have radicalized by consuming extremist content online, many of whom eventually traveled overseas to join the Islamic State. This study examines whether anti-Muslim hostility might drive pro-ISIS radicalization in Western Europe. Using new geo-referenced data on the online behavior of thousands of Islamic State sympathizers in France, the United Kingdom, Germany, and Belgium, I study whether the intensity of anti-Muslim hostility at the local level is linked to pro-ISIS radicalization on Twitter. Results show that local-level measures of anti-Muslim animosity correlate significantly and substantively with indicators of online radicalization, including posting tweets sympathizing with ISIS, describing life in ISIS-controlled territories, and discussing foreign fighters. High-frequency data surrounding events that stir support for ISIS — terrorist attacks, propaganda releases, and anti-Muslim protests — show the same pattern.

Terrorism and the Rise of Right-Wing Content in Israeli Books. Published in International Organization. [Paper][Ungated] [Appendix] [Replication]

In the past few years the Western world has witnessed a rise in the popularity of right-wing political discourse promoting nationalistic and exclusionary worldviews. While in many countries such rhetoric has surfaced in mainstream politics only recently, in Israel, right-wing ideology has been popular for almost two decades. Explanations for this surge focus on Israeli citizens’ attitudinal change in the face of exposure to terrorism, but largely do not account for why such ideas remain popular over the long term, even after violence subsides. This study examines whether the long-lasting prominence of right-wing nationalistic politics in Israel is linked to the perpetuation of right-wing ideology in popular media. Analyzing the content of more than 70,000 published books, this study finds that content related to the political right has increased in Israeli books after periods of terrorism, a change that has become more pronounced over the years. 


Can war foster cooperation?  With Michal Bauer, Christopher Blattman, Julie Chytilová, Joseph Henrich, and Edward Miguel. Journal of Economic Perspectives, 30(3). [Paper] [Ungated] [Appendix] [Replication]

In the past decade, nearly 20 studies have found a strong, persistent pattern in surveys and behavioral experiments from over 40 countries: individual exposure to war violence tends to increase social cooperation at the local level, including community participation and prosocial behavior. Thus while war has many negative legacies for individuals and societies, it appears to leave a positive legacy in terms of local cooperation and civic engagement. We discuss, synthesize and reanalyze the emerging body of evidence, and weigh alternative explanations. There is some indication that war violence especially enhances in-group or “parochial” norms and preferences, a finding that, if true, suggests that the rising social cohesion we document need not promote broader peace.


Contested Ground: Disentangling Material and Symbolic Attachment to Territory. With Guy Grossman and Devorah Manekin. Published in Political Science Research and Methods.  [Paper] [Ungated] [Appendix] [Replication]

Territorial disputes are prone to conflict because of the value of territory to publics, whether due to its strategic and material worth, or to its intangible, symbolic value. Yet despite the implications of the distinction for both theory and policy, empirically disentangling the material from the symbolic has posed formidable methodological challenges. We propose a set of tools for assessing the nature of individual territorial attachment, drawing on a series of survey experiments in Israel. Using these tools, we find that a substantial segment of the Jewish population is attached to the disputed West Bank territory for intangible reasons, consisting not only of far-right voters but also of voters of moderate-right and centrist parties. This distribution considerably narrows the bargaining space of leaders regardless of coalitional configurations. Our empirical analysis thus illustrates how the distribution of territorial preferences in the domestic population can have powerful implications for conflict and its resolution.


Countering Violent Extremism and Radical Rhetoric [Paper] [Appendix]

Countering violent extremism (CVE) is becoming a popular strategy to combat terrorism. Unlike traditional counter-terror measures that focus on repression of militant groups, counter-extremism policies seek to engage civilian populations in ad- dressing factors that facilitate radicalization into terrorism. While CVE initiatives are widespread around the world, there is currently little rigorous research on their effectiveness. This study illustrates how innovations in social media research can shed light on this emerging research frontier by presenting an empirical analysis of a large counter-extremism program in the United States. Drawing on original geo-located Twitter data on thousands of Islamic State sympathizers in the United States, I find that counter-extremism activities led ISIS sympathizers to behave strategically online. Individuals located in proximity to CVE activities began self-censoring expressions of support for ISIS, altering their profile images on Twitter, and encouraging their followers to migrate to Telegram, an encrypted social media platform popular among the group’s supporters. These results shed light on previously unknown patterns linking offine counter-extremism interventions with online engagement with militant groups.


Propaganda and Radicalization in an Internet Age. With Barbara Walter and Gregoire Phillips. 

**Paper will be posted soon**

Many believe that the rise of violent extremism around the world is driven by groups’ ability to disseminate violent content on social media platforms. A popular assumption, based on this view, is that individuals who radicalize are particularly attracted to brutal violence – a notion that has propelled a rapid investment in algorithms that detect and take down violent content shared online. In this article, we challenge this assumption by showing that violent propaganda disseminated by ISIS has been largely ineffective at generating support for the group. Using deep learning, we detect violent imagery in hundreds of ISIS propaganda videos that were disseminated on Twitter between 2015 and 2017. We identify users who were exposed to this content, and study how exposure shaped their subsequent online behavior. We find that violent propaganda decreased expressions of support for ISIS across a wide range of videos, where all but the most enthusiastic supporters were less likely to endorse the group after exposure to its brutalities. In contrast, we find that non-violent content conveying the material, spiritual, and social benefits of recruitment was very effective at increasing support, corroborating many of the theories on the drivers of radicalization.


Terrorism as a Stage for Far-Right Mobilization. In progress.

Research on the electoral success of far-right parties has traditionally focused on demand-side explanations such as voters’ economic and cultural grievances or supply-side accounts highlighting political opportunities. So far, however, there has been little research on contexts that facilitate the interaction of the two. I argue that terrorist attacks move both demand and supply in favor of right-wing populism, making aspects of this ideology resonate with the media and other drivers of the social conversation while simultaneously increasing public sympathy for these ideas. I test the impact of terrorism on far-right politicians’ mobilization efforts on social media, as well as public responses to such events, using high-frequency Twitter data collected around over thirty terrorist attacks between 2010–2016 in Europe and the United States. I find that (a) far-right politicians’ rhetoric becomes significantly more xenophobic and anti-Muslim in the aftermath of terrorism, and (b) such messages become more popular among targeted populations even up to a month after the attacks. While these results present short-term dynamics, they nonetheless highlight the importance of incorporating the security dimension into the study of far-right politics.


Violent Extremism and Social Media: A New Dataset on Islamic State Supporters on Twitter.  In Progress.

The world has witnessed a wave of violent extremism fueled in large part by propaganda disseminated on the Internet. The Islamic State has been one of the most prominent groups to inspire violence and recruit supporters through online means. While online social networks are known to be central to spreading violent extremism, we currently have little systematic data enabling a rigorous micro-level study of the phenomenon. This paper introduces a new geo-located, high-frequency panel dataset on the online behavior of almost two million individuals linked to the Islamic State on Twitter. The dataset includes historical content produced by these individuals, and allows linking online behavior to offline data through information on user geographic locations. These rich data enables testing a large number hypotheses in new and exciting ways.


How Increasing Media Freedom Affects Political Discourse, Knowledge, and Polarization: Tracing the Mechanisms. With Jack Snyder. In progress.

Free news and communications media is one of the central pillars of political life in stable democracies. Without it, citizens would lack the information to evaluate public issues, organize political groups, choose prudently among candidates for office, and hold officials accountable. Consequently, democrats typically take it for granted that increases in media freedom in countries that lack it will contribute to democratization, the enhancement of rights, the rule of law, and social stability. On average, and over the long run, they are certainly correct.  In the short run, however, the impact of increased media freedom on these desirable outcomes is much more complex and varied.  In this project, we empirically study how increases in media freedom are associated with various democratic outcomes in countries across the world, using micro-level data from multiple survey rounds over time.