Cross-Examination

Two opposed parties seek to influence an uninformed decision maker. They invest in acquiringinformation and select what to disclose. The decision maker then adjudicates. We compare thisbenchmark with a procedure allowing adversarial cross-examination. A cross-examiner tests theopponent in order to persuade the decision maker that the opponent is deceitful. How doesthe opportunity or threat of cross-examination affect the parties' behavior? How does it affectthe quality of decision-making? We show that decision-making deteriorates because parties areless likely to acquire information and because cross-examination too often makes the truthappear as falsehood. Next, we consider a form of controlled cross-examination by permittingthe cross-examined to be re-examined by his own advocate, i.e., counter-persuasion. Moreinformation then reaches the decision maker. Decision-making may or may not improvecompared to the benchmark depending on how examination is able to trade off type 1 and 2errors