This paper models the product cycle and explains how it relates to world inequality. In the model, both phenomena arise because skilled people have a comparative advantage in making high-tech products. The model can explain up to a 10:1 income differential between people and up to a 7:1...

If machines are indivisible, a vintage capital model must give rise to income inequality. If new machines are always better than old ones and if society cannot provide everyone with a new machine all of the time, inequality will result. I explore this mechanism in detail. If technology resides...

This paper analyzes how political stability depends on economic factors. Fluctuations in groups' economic capacities and in their abilities to engage in rent-seeking or predatory behavior create periodic incentives for those groups to renege on their social obligations. A constitution remains in...