NBER Working Papers by Nancy Stokey

Recent estimates of the potential growth effects of tax reform vary widely, ranging from zero (Lucas 1990) to eight percentage points (Jones, Manuelli, and Rossi 1993). Using an endogenous growth model, we assess which model features and parameter values are important for determining the quantitative impact of tax reform. We find that the critical parameters are factor shares, depreciation rates, the elasticity of intertemporal substitution, and the elasticity of labor supply. The elasticities of substitution in production, on the other hand, are relatively unimportant. The quantitative estimates in several recent papers are compared with each other and with some of the evidence from U.S. experience.

A growth model is developed in which finite-lived individuals invest in human capital, and investments have a positive external effect on the human capital of later cohorts. Heterogeneous labor is the only factor of production, and higher-quality labor produces higher-quality goods. Stationary growth paths, along which human capital and the quality of consumption goods grow at a common, constant rate, are studied. It is also shown that if a small economy is very advanced or very backward relative to the rest of the world, then its rate of investment in human capital is lower under free trade than under autarky.

In this paper we analyze an aggregative general equilibrimi model in which the use of money is motivated by a cash-in-advance constraint, applied to purchases of a subset of consumption goods. The system is subject to both real and monetary shocks, which are economy-wide and observed by all. We develop methods for verifying the existence of, characterizing, and explicitly calculating equilibria. A main result of the analysis is that current money growth affects the current real allocation only insofar as it affects expectations about future money growth, i.e., only through its value as a signal.

Tournaments, reward structures based on rank order, are compared with individual contracts in a model with one risk-neutral principal and many risk-averse agents. Each agents' output is a stochastic function of his effort level plus an additive shock term that is common to all the agents. The principal observes only the output levels of the agents. It is shown that in the absence of a common shock, using optimal independent contracts dominates using the optimal tournament. Conversely, if the distribution of the common shock is sufficiently diffuse, using the optimal tournament dominates using optimal independent contracts. Finally, it is shown that for a sufficiently large number of agents, a principal who cannot observe the common shock but uses the optimal tournament, does as well as one...