Econ Papers Daily / 期刊论文
证人证言的附条件认罪协议
Contingent plea agreements for witness testimony
摘要
A prosecutor can offer leniency to an eyewitness in exchange for testimony. There is a concern that allowing the prosecutor to make the leniency contingent upon a successful conviction will produce more perjury and the court has thrown out some testimony obtained through such contingent agreements. This article uses a Bayesian jury model to examine the impact of allowing a conviction-motivated prosecutor to design a contingent scheme. It finds that the impact of allowing contingency on the Type 1 error of innocent conviction and the Type 2 error of wrongful acquittal depends on the precision of the additional evidence in the trial. In particular, when the additional evidence is very precise, allowing contingency may reduce both errors. Under a properly designed limit on the amount of leniency, allowing contingency can reduce both innocent conviction and wrongful acquittal.
中文摘要
检察官可以向目击证人提供宽大处理以换取证词。然而，允许检察官将宽大处理与成功定罪挂钩，可能引发更多伪证问题，法院已因此否决了部分通过此类附条件协议获取的证词。本文运用贝叶斯陪审团模型，探讨允许以定罪为动机的检察官设计附条件方案的影响。研究发现，允许附条件协议对无辜者定罪的第一类错误和错误无罪释放的第二类错误的影响，取决于审判中额外证据的精确度。特别是，当额外证据非常精确时，允许附条件协议可能同时减少这两类错误。在适当设计宽大处理限度的情况下，允许附条件协议能够同时降低无辜者定罪和错误无罪释放的发生率。