Do Islamic State’s Deadly Attacks Disengage, Deter, or Mobilize Supporters?

Abstract

What are the consequences of committing violent attacks for terrorist organizations? Terrorist attacks might broaden the base of supporters by increasing the perceived group efficacy. However, terrorist attacks might also lead its supporters to believe that the organization is excessively violent or involvement may become too dangerous. This article employs a unique dataset with 300,842 observations of 13,321 Twitter accounts linked to the Islamic State (IS), collected during a 127-day period, to empirically investigate the impact of terrorist attacks on the number of the organization’s supporters. By exploiting the exogenous timing of terrorist attacks as a natural experiment, we find that the number of followers of IS-related Twitter accounts significantly reduces in the aftermath of the attacks. Additionally, we provide some suggestive evidence to disentangle two mechanisms: disengagement – a change in supporters’ beliefs – and deterrence – demobilization due to fear. Because we do not find support for the latter, we conclude that the disengagement effect might explain our main result.

The Perils of Estimating Disengagement Effects of Deadly Terrorist Attacks Utilizing Social Media Data

“…As suspension removes these accounts from the sample, the accounts left for estimation are biased towards less active accounts, which themselves can lose followers during such periods as a general trend due to lower activity and posting levels. This would skew estimations in the direction of lower or even negative follower growth, akin to that found in the analyses by Barceló and Labzina (2020).…”

“…In this article, I delve into a recent study by Barceló and Labzina (2020) on terrorist (de)mobilization to demonstrate the undue influence that social media platform enforcement decisions can have on otherwise strong research designs. I further discuss the strong demands these problems place on researchers, who need to invest additional effort into guarding their models against such empirical challenges.…”

Constraints and military coordination: How ICTs shape the intensity of rebel violence

“…Moreover, by knowing rebels' violent actions, western countries are prone to label rebels as terrorists and cutting their financial support (Phillips 2019). Other studies show that when rebels conduct attacks with high levels of victims, they tend to lose online support when this information circulates in social media platforms (Barceló and Labzina 2020). In contrast, when rebels publish that they limit their violence against their opponents, they tend to receive more support (Milton 2020).…”

“…11 We estimate the following two models. First, we include a dummy variable equal to one for years 2005, 2006, and 2007 as a proxy to measure social media use given that 2004 was the Facebook's foundation year, Twitter was founded in 2006, and both are the most used social platforms for rebels to share their propaganda (Barceló and Labzina 2020;Jones and Mattiacci 2019;Loyle and Bestvater 2019;Piazza and Guler 2019). Second, we estimate separate effects for different decades (1990s and 2000s) to capture differences in the use of mobile phones and internet in different years.…”

Terrorist campaigns and the growth of the Muslim population: a reply

“…Yet, some clues can be found of a demobilizing impact of attacks. For example, in their study on more than 13 Twitter accounts linked to the Islamic State (IS), Barceló and Labzina (2020) find that the number of followers of IS-related Twitter accounts significantly decrease in the aftermath of the attacks. Therefore, even among more radical people, terrorist events produce more disengagement than mobilization.…”