The Effects of Comparable-Case Guidance on Awards for Pain and Suffering and Punitive Damages: Evidence from a Randomized Controlled Trial

Jurors receive little guidance in determining awards for pain and suffering and punitive damages. Consequently, these awards are notoriously unpredictable, undermining the law’s objectives and causing a wide range of harms. Among the methods that have been proposed for addressing the unpredictability of such awards is the use of information regarding awards in comparable cases (“prior-award information”) as guidance for award determinations. This paper reports and interprets the results of a factorial experiment designed to test the effects of prior-award information at different levels of bias, variability, and form of presentation on the magnitude, spread, and accuracy of awards for pain and suffering and punitive damages. The paper examines juror behavior in response to prior-award information, and interprets whether such information can be expected to improve awards under a robust set of conditions. In summary, the data provide strong evidence that prior-award information improves the accuracy of awards (as defined) and that its beneficial effect on the dispersion of awards generally dominates any distortion, or bias, caused by the information. Furthermore, the data provide evidence that triers of fact respond to prior-award information as predicted in recent literature, and in line with the “optimal” use of such information.