Conservativeness in jury decision-making

This paper studies the three kinds of conservativeness in a jury decision-making structure: the voting rule, the threshold of reasonable doubt, and the legal information system. In a model of simultaneous voting, Feddersen and Pesendorfer (The American Political Science Review, 92(1), 23-35, 1998) argue that the unanimity rule is the worst-performing voting rule because voters with strategic behaviour mitigate the bias brought about by the voting rule. If this bias can be offset by an opposing (less conservative) bias in the legal information system, we would be able to restore the rationality of informative voting. The new informative equilibrium is strictly better than the original strategic equilibrium in terms of ex post error probability. When a strategic equilibrium survives, we can lower the probability of convicted defendant being innocent by making the information system more informative or by forming a jury with a higher (more conservative) threshold of reasonable doubt.