In this paper we study the social, demographic and economic origins of social security. The data for the U.S. and for a cross section of countries make it clear that urbanization and industrialization are strongly associated with the rise of social insurance. We describe a model economy in which...

We develop a span-of-control model where managerial skills are endogenous and the outcome of investments over the life cycle of managers. We calibrate this model to U.S plant-size data to quantify the effects of distortions that are correlated with the size of production units. These distortions...