Functional Forms, Exogenous Shifts, and Economic Surplus Changes
研究了均衡位移模型中精确福利度量的条件，涉及供需函数形式、外生变动类型和百分比变化定义，并分析了不满足条件时的近似误差。
Abstract Conditions for exact welfare measures in equilibrium displacement modeling are examined. These relate to the functional form of supply and demand, the nature of the exogenous shift, and the definition of percentage changes. Approximation errors when these conditions are not met in empirical applications are investigated and analytical expressions for the errors derived. Significant errors are possible when a proportional shift is assumed. The assumptions underlying Alston and Wohlgenant's empirical findings are identified. The restriction that supply must be elastic is shown to be unnecessary.