Research News

Game Theorist Describes Unintended Consequences of U.S. Counterterrorism Policies

World events might not suggest that a decline in terrorism incidents has taken place during the post-Cold War era. Yet, economists have identified just such a trend while revealing that the likelihood of death or injury from terrorism has increased.

Current world events would not suggest that a decline in terrorism incidents has taken place during the post-Cold War era. Yet, that is what Todd Sandler, a University of Southern California (USC) professor, has found in studies conducted with colleague Walter Enders of the University of Alabama in Tuscaloosa.

Sandler and Enders have also found that, despite the declining number of terror incidents, the likelihood of death or injury from terrorism has increased. High on the list of reasons for this trend are the changing face of terrorism involving more religious groups and amateurs, and the way governments respond to terrorist threats.

Sandler and Enders received the 2003 National Academy of Sciences Award for Behavioral Research Relevant to the Prevention of Nuclear War for their work on transnational terrorism using game theory and time series analysis -- techniques that effectively documented "the cyclic and shifting nature of terrorist attacks in response to defensive counteractions." Game theory employs the idea of mutual responses between two thinking, rational agents, such as governments and terrorist groups, as defined in Sandler and Enders’ work.

In a lecture at NSF, Sandler gave insights into game theory and other new economic tools being employed to better understand trends in transnational terrorism, an extension of work he and Enders began with NSF support while they were both at Iowa State University more than 20 years ago.

At that time, they initiated a study of various forms of government "never-to-negotiate" strategies in hostage-taking incidents, as well as a look at negotiated agreements that occur between governments to thwart terrorism. The project also analyzed effective government responses when terrorists can "choose the country to stage their incidents." A paper for The American Political Science Review in 1993, and other writings based on the project, led the Department of State's security office to consult the researchers about policy development.

"Investing in this basic research generated a knowledge base that almost a decade later, with the terrorist attacks of Sept. 11, 2001, was highly sought after as a valuable tool for decision makers," said Dan Newlon, NSF program director for economic sciences.

"We published then that terror increased as security measures were heightened, not the other way around," said Sandler, a Robert R. and Katheryn A. Dockson Professor of International Relations and Economics at USC. "Terrorists just substituted places and people who were less protected."

Bypassing facilities and attacking people instead may have resulted in fewer recorded incidents, but it came with the unintended consequence of greater human costs, Sandler concluded.

Sandler's latest work with Enders involves an advanced look at that trend. Using time series analysis, the two believe they have a better predictive tool than existing methods in determining the lethality of the post-Cold War period of transnational terrorism and for assisting future government policy considerations.

According to Sandler, time series analysis bore out the conjecture that a new brand of terrorism among religious groups and amateurs brought on an increased deadliness of terror acts. Sandler said he believes this creates a dilemma for government counterterrorism measures.

"For example, when metal detectors were placed in most airports, skyjackings and other threats declined, but other events such as hostage-taking took place in greater numbers where facilities were not well protected," he explained. The fortification of U.S. embassies and mission facilities reduced attacks against them specifically, but led to an increase of assassinations of officials and military personnel outside of protected compounds.

Sandler and Enders' work also merges the seemingly disparate areas of economics and political science. According to NSF's Newlon, "An exciting aspect of Sandler and Enders' work is the way they integrate political science and economics to provide these valuable insights into terrorism."

 -- Bill Noxon