Many less developed countries are characterized by inefficient and fairly unstable policies. It is well understood that inefficient policies can result, in some cases, in lower measured productivity. When policies have a stochastic component, fluctuations can add to the standard inefficiencies...

This paper develops a model of HIV diffusion among heterosexual individuals who choose (i) whether to engage in sex, i.e. the source of potential infection, (ii) the nature of their relationship as measured by the endogenous rate of partnership destruction, (iii) the presence of extra-marital...

We develop a model of retirement and human capital investment to study the effects of tax and retirement policies. Workers choose the supply of raw labor (career length) and also the human capital embodied in their labor. Our model explains a significant fraction of the US-Europe difference in...

We develop a model that accounts for several stylized facts about immigrant earnings. First, it implies that new immigrants learn less than natives with the same level of schooling. Second, depending on the age of immigration, it implies that initially, immigrant earnings need not grow faster...

We build a model of retirement and assess what are the main forces that drove the macroeconomic pattern in retirement in the US economy during the 20th century. We in particular consider the role of technological progress, demographic change and the Social Security system.

The paper studies the effect of unstable policies on productivity

The paper analyzes dynamic principal–agent models with short period lengths. The two main contributions are: (i) an analytic characterization of the values of optimal contracts in the limit as the period length goes to 0, and (ii) the construction of relatively simple (almost) optimal...