St. John's Law Review

The Stakes Matter: Empirical Evidence of Hypothetical Bias in Case Evaluation and the Curative Power of Economic Incentives

By:  Daniel R. Cahoy & Min Ding

The ability to effectively preview a jury's opinion of a legal case though hypothetical simulation is becoming ever more important in modern litigation.  Today, it is common for large corporate clients to sponsor mock jury studies to obtain feedback on the effectiveness of particular arguments and potential for liability.  Similarly, many courts utilize summary jury trials to provide a neutral evaluation of a case and facilitate settlement.  However, there is good reason to question the results of such simulations.  The problem is "hypothetical bias," a phenomenon that has been well documented in a variety of experimental contexts in which the lack of real world consequences causes the decision-maker to provide different responses.  The common experimental remedy is the use of rewards or compensation to align subject behavior with the task.  Unfortunately, such measures are not useful in the context of jury decision-making because jurors are not driven by self-interest, but rather by their impact on the welfare of others. 

This paper addresses the problem by proposing a novel incentive structure for jury studies that achieves realistic incentive alignment.  It also presents the results of two experiments using this incentive structure that confirm the existence of the hypothetical bias in a limited context and the effectiveness of the incentive structure.