Research Database

In this paper we present an analytically tractable general equilibrium overlapping-generations model of human capital accumulation, and study its implications for the evolution of the U.S. wage distribution from 1970 to 2000. The key feature of the model, and the only source of heterogeneity, is that individuals differ in their ability to accumulate human capital. Therefore, wage inequality results only from differences in human capital accumulation. We examine the response of this model to skill-biased technical change (SBTC) theoretically. We show that in response to SBTC, the model generates behavior consistent with the U.S. data including (i) a rise in overall wage inequality in both the short run and long run, (ii) an initial fall in the education premium followed by a strong recovery, leading to a higher premium in the long run, (iii) the fact that most of this fall and rise takes place among younger workers, (iv) stagnation in median wage growth (and a slowdown in aggregate labor productivity), and (v) a rise in consumption inequality that is much smaller than the rise in wage inequality. These results suggest that the heterogeneity in the ability to accumulate human capital is an important feature for understanding the effects of SBTC, and interpreting the transformation that the U.S. economy has gone through since the 1970s.

It is argued that economists ought to recognize that modeling in different styles will be appropriate for different purposes or different stages in the development of an area of economics. As an example, the paper displays simulations of a stochastic general equilibrium model which shed light on the interpretation of widely discussed small macroeconomic vector autoregressive models connecting monetary variables to output and prices.

This paper studies a version of the neoclassical growth model where heterogenous establishments are subject to partial irreversibilities in investment. Under such investment technology, the optimal decision rules of establishments are of the (S,s) variety. A novel contribution of the paper is the analysis of the general equilibrium dynamics arising from aggregate productivity shocks. This is a difficult task given the high dimensionality of the state vector, which includes the distribution of establishments across capital levels and idiosyncratic shocks. The paper overcomes this difficulty by developing a suitable computational approach. The model is used to study the importance of investment irreversibilities for macroeconomic dynamics. It is found that investment irreversibilities have no major implications for aggregate fluctuations, even though they are crucial for establishment level dynamics. This result contradicts previous conclusions in the literature which rely on partial equilibrium analysis.