County‐Level Correlates of Terrorist Attacks in the United States

• Author: Bianca E. Bersani,Gary LaFree
• Published date: 01 August 2014
• Date: 01 August 2014
• DOI: http://doi.org/10.1111/1745-9133.12092

RESEARCH ARTICLE

CORRELATES OF TERRORIST ATTACKS

IN THE UNITED STATES

County-Level Correlates of Terrorist Attacks

in the United States

Gary LaFree

University of Maryland

Bianca E. Bersani

University of Massachusetts, Boston

Research Summary

We develop a set of hypotheses informed by a social disorganization frameworkand test

them using newly available data on nearly 600 terrorist attacks in U.S. counties from

1990 to 2011. Our results show that terrorist attacks were more common in counties

characterized by greaterlanguage diversity, a larger proportion of foreign-born residents,

greater residential instability, and a higher percentage of urban residents. Contrary to

the social disorganization perspective but in keeping with most prior research, terrorist

attacks wereless common in counties marked by high levels of concentrated disadvantage.

More generally, we found steady declines in the number of terrorist attacks on U.S.

soil from 1990 to 2011. We discuss the implications of the results for theory, future

research, and policy.

Policy Implications

Terrorism, like ordinary crime, is highly concentrated. Of the 3,144 counties in the

United States, only 250 (7.95%) experienced a terrorist attack from 1990 to 2011; 5

This research was supported by the Resilient Systems Division of the Science and Technology Directorate of

the U.S. Department of Homeland Security through Award Number 2008ST061ST0003 made to the National

Consortium for the Study of Terrorism and Responses to Terrorism (START). The views and conclusions

contained in this article are those of the authors and should not be interpreted as necessarily representing

the official policies, either expressed or implied, of the U.S. Department of Homeland Security or START. We

thank Eric Baumer, Ryan King, and Erin Miller, for assistance with the data and John Laub, Jim Lynch, and Brent

Smith for comments on earlier drafts. Direct correspondence to Gary LaFree, National Consortium for the

Study of Terrorism and Responses to Terrorism (START) and Department of Criminology and Criminal Justice,

8400 Baltimore Avenue, Suite 250, College Park, MD 20740 (e-mail: garylafree@gmail.com).

DOI:10.1111/1745-9133.12092 C2014 American Society of Criminology 455

Criminology & Public Policy rVolume 13 rIssue 3

Research Article Correlates of Terrorist Attacks in the U.S.

counties (0.002% of total U.S. counties) accounted for 16% of all attacks. Moreover,

counties at greatest risk of terrorist attack have identifying characteristics.Just as random

preventive patrol policing has generally been replacedby more targeted strategies, efforts

to counter terrorism might benefit from strategies that target certain counties: those with

high population heterogeneity and great residential instability that are highly urban.

And just as targeting particular neighborhoods raises equity concerns in policing, policies

aimed at counties with particular characteristics pose a challenge for countering terrorist

attacks. However, unlike the situation in policing ordinary crime, high-terrorism-risk

counties are generally not characterized byeconomic disadvantage or a large proportion

of racial and ethnic minorities.

The importance of understanding terrorism in the United States assumed height-

ened prominence in the wake of the coordinated attacks of September 11, 2001.

Yetwith fe wexceptions (Freilich, Chermak, Belli, Gruenewald, and Parkin, 2014;

Smith and Damphousse, 2009), surprisingly little is known about general patterns of ter-

rorist attacks in the United States, including where attacks are most likely to occur and

whether specific characteristics of places increase the risk of attacks. Moreover, most re-

search aimed at understanding the distribution of terrorist attacks has developed without

a firm theoretical foundation. In this article, we develop a set of hypotheses about terrorist

attacks drawn generally from the social disorganization tradition in criminology. Using

data from the Global Terrorism Database (GTD), we test these hypotheses by examining

county-level counts of terrorist attacks in the United States from 1990 through 2011. Our

results are largely consistent with the hypotheses derived. Across the two decades spanned by

our data, terrorist attacks were more common in counties characterized by greater language

diversity, a larger proportion of foreign-born residents, greater residential instability, and a

greater proportion of urban residents. In contrast to social disorganization theory but in

line with prior research on terrorism, attacks were less common in counties with high levels

of concentrated disadvantage. Despite the general applicability of the social disorganiza-

tion perspective for understanding aggregate levels of terrorist attacks in the United States,

much work needs to be done to explain the microlevel processes behind these patterns. We

conclude with a discussion of the implications of the findings for future research and policy.

Geographic Concentration of Crime and Terrorism

Over the past several decades, a growing body of research has found that certain areas are

“hot spots” of criminal activity (Sherman, Gartin, and Buerger, 1989) and that crime is

not randomly dispersed across areas, but instead it is systematically concentrated. In fact,

research has shown that the clustering of ordinary crime in geographic areas is stronger than

the clustering of ordinary crime among individuals. As a result, the prediction of where crime

occurs may be easier than the prediction of who commits it. Specifically, Sherman (1995:

456 Criminology & Public Policy