Costly Evidence and Systems of Fact Finding

This paper compares the relative merits of adversarial and inquisitorial systems of civil procedure in the presence of evidence suppression. Each party has the incentive to suppress evidence that may damage her case, and to reveal any evidence that strengthens her case. I model the decision of a litigant to suppress evidence. The court conditions its action (transfers between the parties) upon the evidence which is revealed. Enforcement costs, which are the cost of suppression and the cost of requesting evidence, are a loss to the relationship and form the basis for my evaluation of the relative merits of each system. I find that neither system always outperforms the other. The strength of the inquisitorial system is that it allows for randomization over evidence requests, which leads to lower expected enforcement cost. Litigants cannot commit to randomize as they are motivated by the expected award in litigation. The strength of the adversarial system is that it sometimes allows litigants to utilize their information about the level of suppression.