立法中的损益权衡之道——法经济学能为立法者做些什么

The Trade-off Between Gains and Losses in Legislation——What Economists Can Do for Legislators

法律经济分析中最常用,也最为传统的决策标准,亦即帕累托标准、卡尔多—希克斯标准(财富最大化标准)、罗尔斯标准,各有其运用的范围与利弊,其中,帕累托标准所需要的信息最少,最为理想,但在实际生活中往往难以达成;卡尔多—希克斯标准要求比较受益者的收益与受损者的损失,当两者可比时,它总能判断法案是否值得实施,并且选择效率优先的方案;但它相对忽视了权利的保护和弱势群体的保障问题;罗尔斯标准对弱势群体保障力度相对最大,但它在促进效率方面具有相当的缺陷。立法者应当在这三种标准中进行有效的抉择,这种选择可以用一个分为两层次的模型来加以概括——在保障基本生活底线的情况下,应当尽量追求帕累托改进和带有充分补偿的卡尔多—希克斯改进,在此基础之上进行成本收益分析,通过并实施那些确能带来更高预期收益的法案,在开放立法和审议民主的前提下,法经济学家可以对立法中的权衡损益作出专业的成本收益评估,从而作出有建设性的贡献。

The most traditional and most widely used decision criteria in economic analysis of law are Pareto criterion,Kaldor-Hicks criterion and Rawls criterion,which respectively have their advantages and disadvantages and scopes for application.Pareto criterion needs the least information and can get most idealized results,but is unattainable in real life.Kaldor-Hicks criterion requires the comparison of benefits of beneficiaries and losses of sufferers.If the comparison can be made,it can always determine whether a proposed law should be implemented and choose the most efficient project.However,this criterion neglects the protection of rights and social security for the disadvantaged groups to some extent.Rawls criterion gives most powerful protection for the disadvantaged groups,but has defects in improving efficiency.The legislators must choose their standard among these three criteria,which can be summarized with in a two-level model.With a guaranteed bottom line of welfare,legislators should pursue Pareto improvements and Kaldor-Hicks improvements with sufficient compensation.On this basis,cost-benefits analysis can be made to discover the laws with more expected benefits.With legislation open to the people and deliberative democracy,economists can give professional assessments for the gains and losses of a particular law and make more contributions for legislation.