Adversarial and Inquisitorial Procedures with Information Acquisition

This article examines the properties of the two most commonly used legal institutions: the inquisitorial system and the adversarial system. In the former system, the judge makes a decision based on her own acquired information, whereas in the latter system, the advocates are required to present their acquired information to the uninformed judge. Within the binary decision framework, I study the circumstances in which one system is superior to the other in terms of accuracy. The following two effects are notable in the adversarial system: The advocates exert more effort regarding information acquisition than the judge, and the adversarial judge gleans additional information from non-disclosure events. However, one inherent weakness of the adversarial system is its communication problem. In cases in which such a problem is more pronounced, the inquisitorial system should prevail despite its lack of incentives for information collection. (JEL D74, D82, D83, K41)