Almost Ideal gravity associates zero trade flows with variable and fixed trade cost variation in a flexible demand system. Latent trade shares between non-partners are inferred from the Tobit estimator applied to trade among 75 countries and 25 sectors in 2006. Latent Trade Bias (LTB) is the...

Why does illegal trade often flourish without formal enforcement, but sometimes fail? Why do illegal trade-reducing policies often fail? Why do States often appear to tolerate illegal trade? A model of trade with cops and robbers provides answers. `Safety in numbers' is a key element: the...

The effects of geography and productivity on the global pattern of production are captured here in a specific factors gravity model. Simple enough for sharp results, the model is yet rich enough to contain the high dimensional productivity frictions in production and distribution of a many...

International economic integration yields large potential welfare effects, even in a static constant returns competitive world economy. Our method is novel. The effect of border barriers on trade flows is often inferred from gravity models. But their rather atheoretic structure precludes welfare...