International trade and monopolistic competition without CES : estimating translog gravity

This paper derives a micro-founded gravity equation in general equilibrium based on a translog demand system that allows for endogenous markups and rich substitution patterns across goods. In contrast to standard CES-based gravity equations, trade is more sensitive to trade costs if the exporting country only provides a small share of the destination country's imports. As a result, trade costs have a heterogeneous impact across country pairs, with some trade flows predicted to be zero. I test the translog gravity equation and find strong empirical support in its favor. In an application to the currency union effect, I find that a currency union is only associated with substantially higher bilateral trade if the exporting country provides a small share of the destination country's imports. For other pairs, the currency union effect is modest or indistinguishable from zero. -- translog ; trade costs ; gravity ; currency union ; monopolistic competition ; trade cost elasticity ; heterogeneity ; zero trade