The Value of Information in the Court - Get it Right, Keep it Tight

Abstract

We estimate an equilibrium model of decision-making in the US Supreme Court which takes into account both private information and ideological differences between justices. We present a measure of the value of information in the court. Our measure is the probability that a justice votes differently that what she would have voted for in the absence of case specific information. We show that in roughly 44% of cases, justices' initial leanings - based on their priors and ideological biases - are changed by justices' personal assessments of the case. The results suggest a sizeable value of information. We evaluate the performance of the Court in different issues and time periods, and use counterfactual simulations to draw implications for institutional design.

Keywords: supreme court, strategic voting, common values, mixture model

JEL Classification: D72, D78, C13