Gravity equations have been used for more than 50 years to estimate ex post the partial effects of trade costs on international trade flows, and the well-known - and traditionally presumed exogenous - "trade-cost elasticity" plays a central role in computing general equilibrium trade-flow and...

Despite widespread anecdotal evidence that lower trade barriers increase international trade, there is little firm quantitative evidence of the ‘trade-cost elasticity’ of trade flows, one of the two key aggregate statistics that have recently been identified as sufficient to quantify the...