Consumer's Surplus as an Exact Approximation When Prices are Appropriately Deflated
提出一种价格归一化形式，推广了常用的消费者剩余表达式，并证明在价格适当缩减时，消费者剩余三角形-矩形方法可作为理论上有意义的等价变差或支付意愿函数的精确近似。
A canonical price-normalized form is proposed as a generalization of the ordinary consumer's surplus expression commonly used to evaluate changes in economic welfare. This familiar-looking formula, it is proved, can be rigorously interpreted as representing the first- and second-order terms of a Taylor-series expansion for the equivalent-variation or willingness-to-pay function of a single consumer. In principle, the lowly consumer's surplus triangle-and-rectangle methodology can be rigorously defended as an exact approximation to a theoretically meaningful measure as long as prices are appropriately deflated. The appropriate price deflator is derived, and some implications are discussed.