城市水价预测模型研究与GMM参数校验

Forecasting Water Pricing model based on Marginal-cost

摘要:

主要介绍城市水价预测边际成本方法数学模型及其GMM估计的研究。首次将水价模型分割为可变成本函数与固定成本函数两部分，为了减小预测误差对每部分函数参数进行了GMM估计与校验。并从水的供应与需求两个方面对水价数学模型进行了详细描述，以我国某地区实际数据为样本对水价预测模型与GMM估计进行了应用；在水价预测模型中还以城市给水管网长度为规模参数，模拟了边际成本定价及其社会剩余变化对管网规模效应的影响。揭示了水价边际价格与边际成本之间的差异，以及城市给水管网规模效应范围及其与水价之间的敏感程度，表明了城市水价预测最优定价的特点。

Abstract:

The purpose of this paper is to evaluate the pricing of water utilities by GMM (generalized method of moments) estimation. An econometric model describing both water supply and demand is specified and estimated on utilities located east in China. Based on the GMM estimated technology and demand parameters, simulate marginal-cost pricing and social surplus variations. We derive the estimated parameters and discuss estimates of returns to scale and elasticities of water demand, analyze the current pricing of water utilities by comparing marginal costs and marginal prices. These estimates are then used to simulate first-best optimal pricing by solving a supply-demand system in prices and quantities. We show that the optimal pricing scheme is characterized, first by higher marginal prices and second by a lower fixed charge.