The purpose of the paper is to measure the potential bias in the U.S. import price index due to the appearance of new product varieties, or new foreign suppliers, and determine the effect of this bias on the estimated income elasticity of import demand. Existing import price indexes are based on...

This paper argues that the theoretical foundations for the gravity equation are general, while the empirical performance of the gravity equation is specific to the type of goods examined. Most existing theory for the gravity equation depends on the assumption of differentiated goods. We show...

This paper describes the updating of the NBER trade dataset, which now provides U.S. import and export values to the year 2001, disaggregated by Harmonized System (HS), Standard International Trade Classification (SITC), and the U.S. Standard Industrial Classification (SIC) categories. In...