We construct a Blanchard-style overlapping generations model consisting of long-lived individuals who have uninsurable idiosyncratic risk resulting from uncertain retirement periods and medical costs in retirement. Without social insurance, such individuals must save for these eventualities. We...

This article studies socially optimal allocations, from the point of view of a benevolent social planner, in environments characterized by fixed resources, endogenous fertility, and full information. Individuals in our environment are fully rational and altruistic toward their descendants. Our...

I study the effect of task difficulty on workers' effort. I find that task difficulty has an inverse-U effect on effort and that this effect is quantitatively large, especially when compared to the effect of conditional monetary rewards. Difficulty acts as a mediator of monetary rewards:...

Traditionally, observed fluctuations in aggregate economic time series have been mainly modeled as being the result of exogenous disturbances. A better understanding of macroeconomic phenomena, however, surely requires looking directly at the relations between variables that may trigger...

The present paper presents a standard overlapping generations model with external habits formation and environmental quality in the utility function. Our main objective is to study the impact of external habits on capital accumulation and environmental quality on the intertemporal competitive...

This paper studies recursive exchange economies with short sales. Agents maximize discounted expected utility. The asset structure is general and includes real securities, infinite-lived stocks, options, and other derivatives. The main result shows the existence of a competitive equilibrium...

I model an incomplete markets economy where unaware agents do not perceive all states of nature, so unintended default can occur when asset returns differ from what was perceived. The presence of default plays a crucial role in the proof of existence - particularly in economies where beliefs are...

This paper examines a stochastic model to determine optimal pricing, waiting time, output, and sizing decisions for service firms which compete on time in an uncertain environment. Sizing decisions concern optimal service capacity and maximum physical waiting room (with a given probability)....