Political Interventions in the Administration of Justice

Politicians may often be tempted to direct the prosecution of their political opponents. We argue that the informational consequences of prosecution are an important determinant of such interference, because only when a prosecutor is free to follow the evidence can his decisions convey information to the public about an opponent's likely guilt - or innocence. We build a game-theoretic model to investigate the implications of this effect. We find that when public opinion is moderately against an incumbent, interference comes at an informational cost, by preventing the public from updating negatively about an opponent. By contrast, when public opinion moderately favors the incumbent, interference confers an informational benefit by preventing the release of potentially exonerating information. Moreover, an accurate court system may sometimes incentivize interference, because it allows citizens to learn even if the initial prosecution was tainted, and, by protecting the truly innocent, may decrease the prosecutor's concerns about wrongful convictions.