In this comment, we show that the existence of the preemption equilibrium in Fudenberg and Tirole (Review of Economics Studies, vol. 52, PP. 383-401, 1985)'s continuous-time games of timing is not guaranteed under their assumptions.

As suggested by empirical evidence, law enforcement in one market often results in adverse effects in others. Current theoretical models are ill-suited to investigate this, because while we already know much about the optimal law enforcement for a single market or multiple but independent...