Conventional aggregate trade elasticity estimates hardly vary across countries. We introduce an aggregate elasticity that is implied by theory: It is the value that equates the welfare gains from trade as implied by one‐ and multi‐sector versions of the model in Arkolakis et al. (American Economic Review, 102 (2012):94–130). These estimates are predicated on sector‐level values for trade elasticites, which we provide at three‐digit levels for 28 developed and developing countries. The values for this aggregate elasticity vary greatly across countries, and they do so because of countries' patterns of production and because a given sector‐level elasticity displays considerable cross‐country heterogeneity.