演講者簡介 : Prof. Tsai, Tsung-Sheng為Ph.D. in Economics，University of Wisconsin-Madison (2002)。
現為本所助研究員。
其主要研究領域為Public Economics、Microeconomics及Political Economics。
演講摘要 : Judicial torture to elicit information or confession is a common practice in pre-modern societies, both in the East and the West. Moreover, often it was applied not only on the suspects, but also to the witnesses and plaintiffs as well. This paper proposes a theory for judicial torture. It is shown that if the judge aims to balance type I and type II errors in decision-making, then torture can improve social welfare by forcing the guilty to confess with higher probability than the innocent, and thereby decrease type I error, although at the cost of increase in type II error. In that case torturing the witnesses might also be welfare-improving, as it helps to screen the cases so that only those with greater merits come into the court. When the information revealed during investigation improved as a result of technological advance, a judicial system based on torture becomes inferior to one based on evidence. This explains the historical development of the judicial system.
