Chapter,环境价值评估概念说课.ppt

3.决策的规范性标准Normative Criteria for Decision-Making 现在，如何用该种分析方法评估行动方案：It is now possible to show how this analysis can be used to evaluate actions. 首先，计算行动方案的净效益现值 First， calculate the present value of net benefits from the action 其次，如果现值大于0 ，则支持该方案，否则则不支持该方案。 If the present value is greater than zero, the action should be supported. Otherwise it should not. 4.获得最优的解决方案Finding the Optimal Outcome 4.1 如何应用经济学成本收益方法识别最优方案 4.2 静态效率 4.3 动态效率 4.获得最优的解决方案Finding the Optimal Outcome 4.1 如何用成本收益法识别最佳或最优方案？ 三个步骤展开规范性分析：Three steps proceeded by normative analysis: First，识别最优方案 we will identify an optimal outcome. Second，识别机构制定的最优方案的程度，现实的方案与最佳方案的差异，揭示 产生上述问题的行为上的原因。 we will attempt to discern the extent to which our institutions produce optimal outcomes and, where divergences （分歧）occur between actual and optimal outcomes, to attempt to uncover the behavioral sources of the problems. Finally ，设计适宜政策 designing appropriate policy solutions. Examples:资源耗竭的海洋渔业 海洋渔业增加，鱼群数量减少威胁到了商业渔业的存在，不仅威胁海洋生物多样性，也使渔民和依赖渔业的社区构成威胁。 the rising number of depleted（废弃的）ocean fisheries（渔场）， Depleted fisheries not only jeopardize（危害）oceanic biodiversity（生物多样性）, but also pose a threat to both the individuals who make their living from the sea and the communities that have depended on fishing to support their local economies. 经济学家如何理解并解决这一问题？How would an economist attempt to understand and to resolve this problem? Examples:资源耗竭的海洋渔业 首先，定义渔业的最优存量或最优渔业捕捞率。The first step would involve defining the optimal stock （存量）or the optimal rate of harvest of the fishery. 其次，与渔业的实际存量、捕捞量比较。这里发现，实际存量低于最优水平，存在过度捕捞The second step would compare this level with the actual stock and harvest levels. 第三，相应的政策的实施，渔业资源得到恢复。The third step would reach the solutions. 人口，能源，矿产，农业，大气，水污染，及其他主题，都采用类似的分析方法。 所有这一切都从最优开始 经济学的分析方法有助于找到问题的解决之道。 4.2 静态效率 Static Efficiency 规范经济学中，静态效率（效率）是判断同一时点上不同资源配置方案的主要标准。The chief normative economic criterion（标准）for choosing among various allocations occurring at the same point in time is called