生态补偿中减少信息租金的机制设计——以张掖市为例

In Payments for Environmental Services(PES) scheme, the opportunity costs of providing Environmental Services(ES) are the landowners’ private information, which farmers tend to hide and overstate. Because of the asymmetric information between landowners and conservation agents in the markets, there is problem of “information rents”, which can limit the effectiveness of PES systems and can make them expensive to implement. The research topic of this project is the mechanism design for reduction of information rents in PES based on Asymmetric Information. There are three policy mechanisms which can reduce information rents in varying degrees in PES programs: (1) gathering more information on landowners in the form of costly-to-fake signals, and then using this information to deduce landowners’ true opportunity costs; (2) screening contracts to differentiate the various types of landowners; and (3) using procurement auctions to introduce competitive forces so as to reduce the information rents.. This project proposes to use panel data model, Principal-agent model, mechanism design theory and auction theory to design the three policy mechanisms as above. Then use field investigation and experiment to analyze the ability of reducing information rent in the study area. The results of this project would provide scientific evidence to formulate the compensation in PES.

在生态补偿项目中，因为参与项目的机会成本是生态系统服务提供者的私人信息，所以在确立补偿标准时提供者与购买者之间存在信息不对称的现象，继而会引发信息租金的问题，导致了生态补偿整体效率的降低。本项目拟以甘肃省张掖市为研究区，以退耕还林和退牧还草两类生态补偿项目为分析对象，利用面板数据模型、委托-代理模型、机制设计原理和拍卖理论的方法，设计信息披露、筛选合同和拍卖三种机制，并通过入户调查和野外试验分析这三种机制在生态补偿项目中减少信息租金的高低和优劣，评估这三种方案在研究区的适用性，为生态补偿项目制定合适的补偿标准提供科学依据。

在生态补偿项目中，因为参与项目的机会成本是提供者的私人信息，所以在确立补偿标准时提供者与购买者之间存在信息不对称的现象，继而会引发信息租金的问题，导致了生态补偿整体效率的降低。本项目以甘肃省张掖市为研究区，以退耕还林和退牧还草两类生态补偿项目为分析对象，设计了信息披露、筛选合同和拍卖三种减少信息租金机制，并通过入户调查和野外试验分析这三种机制在生态补偿项目中减少信息租金的高低和优劣，评估这三种方案在研究区的适用性。首先利用信息披露推导机会成本。项目披露了归一化植被指数（NDVI）、土纲类型和道路网加权密度值并构建这些信息与农牧民机会成本的计量模型，发现这三类信息能较好的披露张掖市退耕还林和退牧还草项目的机会成本。其次项目利用筛选合同判定机会成本类型。项目构建了筛选合同的模型，确立了合同的关键参数并对模型进行分析发现，设计出满足激励相容的自我选择机制合同是筛选合同的关键。继而项目组织试验拍卖判定机会成本。首先构建了最优投标报价模型，并基于此在张掖市肃南县组织了退牧还草生态补偿项目的拍卖试验，分析了统一支付（一刀切支付）、差异支付（报价不同支付不同）和机会成本支付三种拍卖方式下的赢得拍卖人数（可参与项目的人数）、平均投标价、总支付额度以及减少信息租金的差异。最后项目从理论分析和实证分析两个角度比较信息披露、筛选合同和拍卖这三种机制的差异，并选择合适的方案制定补偿标准。