An Experimental Comparison of Adversarial Versus Inquisitorial Procedural Regimes

This article reports the results of a multiyear series of economic experiments comparing the two dominant types of legal procedures used in adjudication: (1) the 'adversarial' model of party-controlled procedure versus (2) the 'inquisitorial' model of judge-controlled procedure. The principal finding is that the relative fact-finding efficiency of the two systems, in terms of both the 'revelation' of hidden facts and the 'accuracy' of decision, depends significantly upon the information structure. Under a 'private' information structure, inquisitorial procedure is relatively more efficient, whereas under a 'correlated' information structure, adversarial procedure is relatively more efficient