WHAT DETERMINES ENTREPRENEURIAL CLUSTERS?

We contrast two potential explanations of the substantial differences in entrepreneurial activity observed across geographical areas: entry costs and external effects. We extend the Lucas model of entrepreneurship to allow for heterogeneous entry costs and for externalities that shift the distribution of entrepreneurial talents. We show that these assumptions have opposite predictions on the relation between entrepreneurial activity and firm‐level TFP: with different entry costs, in areas with more entrepreneurs firms' average productivity should be lower; with heterogeneous external effects it should be higher. We test these implications on a sample of Italian firms and unambiguously reject the entry costs explanation in favor of the externalities explanation. We also investigate the sources of external effects, finding robust evidence that learning externalities are an important determinant of cross‐sectional differences in entrepreneurial activity.     

WHAT MEASURE OF INFLATION SHOULD A CENTRAL BANK TARGET?

This paper assumes that a central bank commits itself to maintaining an inflation target and then asks what measure of the inflation rate the central bank should use if it wants to maximize economic stability. The paper first formalizes this problem and examines its microeconomic foundations. It then shows how the weight of a sector in the stability price index depends on the sector's characteristics, including size, cyclical sensitivity, sluggishness of price adjustment, and magnitude of sectoral shocks. When a numerical illustration of the problem is calibrated to U.S. data, one tentative conclusion is that a central bank that wants to achieve maximum stability of economic activity should use a price index that gives substantial weight to the level of nominal wages. (JEL: E42, E52, E58)     

WHAT GOOD IS WEALTH WITHOUT HEALTH? THE EFFECT OF HEALTH ON THE MARGINAL UTILITY OF CONSUMPTION

We estimate how the marginal utility of consumption varies with health. To do so, we develop a simple model in which the impact of health on the marginal utility of consumption can be estimated from data on permanent income, health, and utility proxies. We estimate the model using the Health and Retirement Study's panel data on the elderly and near‐elderly, and proxy for utility with measures of subjective well‐being. Across a wide range of alternative specifications and assumptions, we find that the marginal utility of consumption declines as health deteriorates, and we are able to clearly reject the null of no state dependence. Our point estimates indicate that a one‐standard‐deviation increase in the number of chronic diseases is associated with a 10%–25% decline in the marginal utility of consumption relative to this marginal utility when the individual has no chronic diseases. We present some simple, illustrative calibration results that suggest that state dependence of the magnitude we estimate can have a substantial effect on important economic problems such as the optimal level of health insurance benefits and the optimal level of life‐cycle savings.