Ambiguity Aversion and the Criminal Process

This is the first article to examine the effects of ambiguity aversion on the criminal process. Ambiguity aversion is a person’s rational attitude towards probability's indeterminacy. When a person is averse towards such ambiguities, he increases the probability of the unfavorable outcome to reflect that fear. This observation is particularly true about a criminal defendant who faces a jury trial. Neither the defendant nor the prosecution knows whether the jury will convict the defendant. Their best estimation relies on a highly generalized probability that attaches to a broad category of similar cases. The prosecution, as a repeat player, is predominantly interested in the conviction rate that it achieves over a long series of cases. It therefore can depend on this general probability as an adequate predictor of this rate. The defendant only cares about his individual case and cannot depend on this general probability. From the defendant's perspective, his individual probability of conviction is ambiguous. The defendant consequently increases this probability to reflect his fear of that ambiguity. Because most defendants are ambiguity-averse, while the prosecution is not, the criminal process systematically involves and is thoroughly affected by asymmetric ambiguity-aversion.