Characterizing Some Gorman Engel Curves
刻画了所有效用导出的需求系统，其恩格尔曲线在收入和收入的任意函数上都是线性的，涵盖了过去使用加总数据估计的几乎所有需求系统，并扩展了戈尔曼对秩二系统的研究。
This paper characterizes all utility derived demand systmes having Engel curves that are linear in both income and an arbitrary function of income. This class encompasses virtually all utility derived demand systems that have been estimated in the past using ag gregate data with explicit treatment of the problem of aggregation ac ross individuals. It includes extensions of the PIGLOG and PIGL class es that have similar properties to these classes, but allow for more general Engel curve shapes. This paper extends W. M. Gorman's study o f these forms primarily by characterizing systems of rank two. The ap plication of the characterized systems to problems of nesting, separa bility, flexibility, Engel curve analysis, estimation, and aggregatio n are briefly discussed. Copyright 1987 by The Econometric Society.