水权交易比率制度的设计与模拟

A Trading-ratio System for Water Market

在传统水权交易制度下 ,不同用户之间的水权交易可能会减少交易双方之间河段、以及后续河段的留川水量。由于此第三者负效应的存在 ,水权交易一直难于应用与实施。本文设计了一套简单易行的水权交易比率制度。首先 ,政府规定各河段的最小留川水量需求 ;接着 ,根据留川水量需求决定各河段水权的初始分配 ,并根据交易双方用水的回流系数规定各用水者之间的交易比率。

Traditional water right trading between different users may bring third-party effects as reducing the instream flow of the intermediate stream and downstream. A set of simple trading rules of water market is designed to avoid third-party effects. The initial water right is distributed to meet the minimum instream flow standard which the authority sets exogenously, and the trading ratios are set by the authority too. The trading ratios are set exogenously based on return flow parameters to ensure that any trading would not violate minimum instream flow standards and consequently to reduce the transation costs. This paper shows that the trading rules can take care of the location effects of users and can achieve social optimal when only local return flows occurs. While in the case of cross-zonal return flows, the trading may not bring the optimal outcome which dues to the minimum instream flow standard which is used to avoid third-party effects.