New product varieties and the measurement of international prices
指出美国进口的高收入弹性可能源于价格指数遗漏新产品种类，并提出修正方法，应用于六类制成品后发现修正指数能部分解释高弹性。
The high income elasticity of demand often estimated for U.S. imports may be a spurious result of omitting new product varieties from the import price indexes. The purpose of this paper is to demonstrate how to incorporate new product varieties into a constant-elasticity-of-substitution aggregate of import prices. This method is applied to U.S. imports of six disaggregate manufactured goods. It is shown that the corrected indexes are able to account for part--but not all--of the high income elasticities. Copyright 1994 by American Economic Association.