We set up two rival Computable General Equilibrium (CGE) models of world trade, one based on classical theories of comparative advantage, the other based on recent gravity theories. We have tested them by indirect inference on the time-series of trade facts for five major countries or country...

We estimate productivities at the sector level for 72 countries and 5 decades, and examine how they evolve over time in both developed and developing countries. In both country groups, comparative advantage has become weaker: productivity grew systematically faster in sectors that were initially...