International Finance Discussion Papers (IFDP)
January 2003
Long-Run Supply Effects and the Elasticities Approach to Trade
Joseph E. Gagnon
Abstract:
Krugman (1989) argued that differences across countries in estimated income elasticities of import demand are due to omission of an exporter supply effect. He showed that such an effect can be derived in a theoretical model with economies of scale in production and a taste for variety in consumption. In his model, countries grow by producing new varieties of goods, and they are able to export these goods without suffering any deterioration in their terms of trade. This paper analyzes U.S. import demand from different source countries and finds strong evidence of a supply effect of roughly half the magnitude (0.75) of the income elasticity (1.5). Price elasticities for the most part are estimated close to -1, which is typical for the literature. Exclusion of the supply effect leads to overestimation of the income elasticity. Results based on U.S. exports to different destinations are less robust, but largely corroborate these findings.
Keywords: Import demand, income elasticity, international trade, product differentiation
PDF: Full Paper
Disclaimer: The economic research that is linked from this page represents the views of the authors and does not indicate concurrence either by other members of the Board's staff or by the Board of Governors. The economic research and their conclusions are often preliminary and are circulated to stimulate discussion and critical comment. The Board values having a staff that conducts research on a wide range of economic topics and that explores a diverse array of perspectives on those topics. The resulting conversations in academia, the economic policy community, and the broader public are important to sharpening our collective thinking.