Dynamic Political Investigations: Obstruction and the Optimal Timing of Accusations

This paper explores how an opposition party strategically times evidence-backed accusations against a political candidate, knowing that their accusation will trigger a formal investigation which the candidate may obstruct. Obstruction is costly but slows down the arrival rate of incriminating information. The candidate’s probability of election is decreasing in voters’ belief that the candidate is guilty, and if the investigation uncovers evidence of wrongdoing, he may face legal penalties. We characterize how the optimal obstruction strategy changes over the course of an investigation and determine when the opposition releases evidence to trigger an investigation. When the election is close and evidence is credible or the opposition is the clear front-runner, they wait until right before the election to release evidence—an October Surprise—leaving the investigation no time to search for additional evidence before voting occurs. In contrast, when the election is close and evidence is weak or the candidate is the clear front-runner, the opposition releases evidence immediately to allow time for a full investigation. Obstruction interacts with this timing decision by making investigations less informative and inducing more October Surprises, which reduce voter information and welfare.