The welfare costs of price controls and rent seeking in a class experiment
通过课堂实验，研究了价格管制带来的两种效率损失：标准福利损失三角和因无法排除高成本卖家或低价值买家导致的“不完美选择效应”，后者可能与传统哈伯格三角损失一样大。
Abstract There are two efficiency effects of price controls: an “output effect” measured by the standard welfare loss triangles, and an “imperfect selection effect” that arises when controls prevent price from excluding high-cost sellers or low-value buyers. Although not discussed in most textbooks, the imperfect selection effect can be as large as the standard Harberger triangle welfare loss in symmetric designs, as confirmed by a class experiment described in this paper. The experiment also permits an analysis of the ways random non-price allocations shift the relevant supply function, and the related effects of rent-seeking competition that can arise with price controls.