Optimal Proof Burdens, Deterrence, and the Chilling of Desirable Behavior

Abstract

The optimal stringency of the burden of proof is characterized in a model in which relaxing the proof burden enhances deterrence but also chills desirable behavior. The result are strikingly different from those in prior work that uses a simpler model in which individuals only choose whether to commit a harmful act (so only deterrence is at stake). Moreover, the qualitative differences between the optimal rule and the familiar preponderance of the evidence rule—and related rules that look to Bayesian posteriors—are great, much more so than revealed by prior work.