According to the ‘Madman Theory’ promoted by Richard Nixon and early rationalist scholars, being viewed as mentally unstable can help a leader coerce foreign adversaries. This article offers the first large-N test of this theory. The author introduces an original perception-based measure of leaders' reputations for madness, coded based on news reports, and analyzes its effect on both general deterrence and crisis bargaining. The study also tests several hypotheses about the conditions under which perceived madness is expected to be more or less helpful. The author finds that perceived madness is harmful to general deterrence and is sometimes also harmful in crisis bargaining, but may be helpful in crisis bargaining under certain conditions. The analysis suggests that the harmful effect of perceived madness results from a commitment problem.
