正当防卫证明问题的法律经济学分析

我国刑事诉讼中正当防卫的证明责任、证明标准及证明方式等问题，在理论、制度和实践上都有太多争议，以致出现要么无罪要么死刑的极端差异裁判结果。借助法律经济学一以贯之的成本效益分析工具，通过权衡证明成本、预期错案损失、未来类似案件的社会总成本和法院裁判成本等因素，应要求被告人首先建立以合理怀疑为标准的争点，再由控方排除合理怀疑地予以证伪。辩方形成正当防卫争点时无需完整的印证链条，法官可通过自由心证进行判断。如此方能在合理的证明成本和裁判成本范围内尽可能发现真相，且即便出现错案也能确保损失最小，并引导人们在未来选择成本最低的行为方案。
Proof of Self-defense in China, including the allocation of burden of proof, the setting of standard of proof, as well as the application of proof method, is highly controversial in both theories and practice, which resulted in extreme cases where similar facts led to acquittal in one case, but death penalty in another case. By the cost-benefit analysis of Law & Economics research, after balancing the cost of proof, potential damage of erroneous verdict and overall social disutility of similar cases, the defendant should be asked to establish reasonable doubt of self-defense first, and then the prosecution will exclude the doubt. The defendant does not need a chain of corroborative evidence to raise the issue of self-defense, and the judge shall decide the issue with free proof. Such a proposal will ensure that 1) factual truth can be ascertained to the best within reasonable limitation of costs, 2) even if erroneous verdicts arise, their damages are kept to the minimum, and 3) reasonable people will choose the lowest cost behavior plan in the future.