The Effectiveness of Antiterrorism Policies: A Vector-Autoregression-Intervention Analysis

Abstract

This chapter aims to employ vector autoregression techniques to identify the interrelationships among the time series for different kinds of terrorist events. These interrelationships should assist people to identify modes that behave as substitutes or complements for one another. Modes are complements if they enhance one another's effectiveness. The chapter investigates the short-run and long-run impact of alternative policies on terrorist tactics and activity levels when the interrelationships between various modes are explicitly taken into account. By indicating the impact of a policy on a host of terrorist attack modes, this procedure better enables us to evaluate the costs and benefits associated with a policy. The ability to identify interrelated time series would also assist in forecasting future trends in terrorism, especially if a contemplated intervention is predicted to affect one terrorist tactic or mode of attack directly. Significant interrelationships among series are uncovered that influence the impact of antiterrorism policies.