Abstract: The authors use the Quadratic Almost Ideal Demand System (QUAIDS) to analyze the household water demand of Beijing which holds multi-attributes as the case study with comparison to double logarithmic demand model and Almost Ideal Demand System (AIDS). The results show that 1) for the lowest income groups, Engel Curves of household water demand are linear, however, for the higher income groups, Engel Curves are non-linear; 2) values of income elasticity of different income groups from QUAIDS are generally higher than those from double logarithmic demand model and AIDS and values of price elasticity are close.

Key words: QUAIDS, AIDS, double logarithmic demand, income elasticity, price elasticity

摘要： 以北京市城市居民用水消费为例, 应用能更准确刻画恩格尔曲线的二次近似完美的需求体系(QUAIDS), 对用水需求弹性进行分析, 并与双对数和近似完美的需求函数(AIDS)所分析的结果进行对比。结果表明: 1) 对于收入较低的前两个群组, 用水消费的恩格尔曲线为线性, 而收入较高的其他群组的恩格尔曲线呈现非线性特征; 2) 应用二次近似完美的需求体系估计得到的不同收入群组的收入弹性要普遍高于其他两类需求函数的估计结果, 而价格弹性的估计结果则较接近。研究结果从一定程度上反映出二次近似完美的需求体系是针对收入弹性估计的改进, 对价格弹性的估计并不产生显著影响。

关键词: QUAIDS, AIDS, 双对数需求模型, 收入弹性, 价格弹性