Pretrial Beliefs and Verdict Accuracy: Costly Juror Effort and Free Riding

Abstract

If jurors care about reaching the correct verdict, but also experience costs to paying attention during the trial, even a small effort cost generates interesting interactions between pretrial beliefs and verdict accuracy. I demonstrate the existence of a strong free riding effect; jurors respond to a more informative prior by reducing their probabilities of paying attention, to the extent that over a non-empty range, a more informative prior will be associated with poorer verdicts. Pretrial beliefs can depend on several factors: I consider two – the extent of discovery during the pre-plea bargaining process, and the efficiency of the police. My results imply that more liberal discovery rules, which result in a less noisy plea bargaining process, will actually be complemented by greater juror effort over a range, resulting in more accurate verdicts. In contrast, greater police efficiency will, over a range, elicit a sufficient drop in juror effort such that verdicts are less accurate. Thus, improving discovery has added benefits over a range, while the benefits of exogenous improvements in policing may be dampened. I briefly extend the model to cases where attentive jurors receive an imperfect public signal instead of a perfect one, and to cases where jurors’ utilities from convicting a guilty defendant differ from their utilities from acquitting an innocent one.