We derive a simple equation to calculate the global welfare impact of the simultaneous reduction of trade costs between multiple country-pairs. Interestingly, we find that we obtain the same equation for a broad class of trade models. Moreover, balanced trade is mostly not required for the...

We construct a tractable general equilibrium model of cumulative innovation and growth, in which new ideas strictly improve upon frontier technologies, and productivity improvements are drawn in a stochastic manner. The presence of positive knowledge spillovers implies that the decentralized...