Defending Multiple Terrorist Targets

This paper analyzes a situation where multiple targets are exposed to a potential terrorist attack. The probability of an attack is determined endogenously in a game where a terrorist chooses the target while the targets independently determine the level of deterrence. As each target tries to divert an attack to others, the symmetric equilibrium becomes suboptimal and exhibits dispersion in the level of deterrence. The analysis shows that the first best deterrence level may be achieved when the targets can write a binding risk-sharing contract. Such a contract has limited applicability however as it suffers from a potential verification problem.