Cover Page -- Title Page -- Copyright Page -- Contents -- I Introduction -- II Trade Elasticities: Practice ahead of Theory -- A Practice -- B Theory -- 1 No Firm Entry -- 2 Allowing for Firm Entry -- 3 The Price Elasticity of Imports -- III Identification -- A Microeconomic Estimates -- B Homogeneous Estimates -- C Data -- IV Results and Relevance -- A Microeconomic Results -- 1 Microeconomic estimates of the elasticity of substitution -- B Macroeconomic Results -- 1 Estimation with common correlated effects -- C Relevance -- 2 The J-curve in a two-sector BKK model -- D Stability -- 2 Variants on the weights -- 3 Estimation without common correlated effects -- V Conclusion -- A Aggregation and Homogeneity -- B Heterogeneous Supply -- C The Price Elasticity of Imports -- D Derivation of the Supply Curve -- E Estimated Variances -- F A Two-Sector Version of BKK -- F. 1 Benchmark Parameter Values taken from BKK (1994) -- References -- Footnotes.