Knowledge that Transforms

In the absence of perfect annuity markets, individual consumers generally undertake precautionary saving to provide resources for their future consumption in the event that they live longer than expected. Kotlikoff, Shoven, and Spivak (in this issue) (hereafter KSS) have provided us with a well-conceived and well-executed study of the effects of various annuity arrangements on individual and aggregate saving in the presence of lifetime uncertainty. Each of these authors has had a long-standing interest in this area, and their current paper reflects their accumulated expertise. Their results indicate that a potentially sizable fraction of U.S. household wealth represents precautionary saving resulting from the absence of perfect annuity market.

The proposition that there is a large and growing black middle class is a major tenet of much recent work on black economic progress. This paper examines one aspect of middle-class status for black families, namely, the stability of high earnings among young male household heads. It finds that, while such men are much less likely to have high earnings than are their white counterparts, there are only small racial differences in the stability of high earnings over time.

The classic case of nonconvexity in consumer opportunities is that of labor supply. While most studies of labor supply concentrate on the individual agent in partial equilibrium, this study considers general equilibrium. I show that even with nonconvex consumer opportunites, such as those involved in the labor supply decision, the standard theorems of general equilibrium models still hold.

Aggregate data exhibit procyclical movement in the rate of turnover. However, existing models of turnover have been unable to explain this phenomenon. In this model I generate turnover as an outcome of a second-best wage contract when there is asymmetry of information about workers' mobility costs. A wage contract that insures the "bad" ("unlucky") workers results in "good" ("lucky") workers earning less than their marginal productivity. Therefore, good workers with low mobility costs leave the firm for the spot market wage. This, combined with an aggregate shock, results in a procyclical rate of turnover.

Among fraternal pairs from the Wisconsin Longitudinal Study_(1980), the authors model the effects of measured and unmeasured family back ground factors, mental ability, and schooling on occupational status and earnings. The models are estimated from incomplete data with corrections for measurement error, and they permit direct comparisons of within- and between-family regressions. The authors find no evidence that the effects of family background lead to a bias in the effect of mental ability on schooling or in the effects of schooling on occupational status or earnings.

Contract and search theories are integrated to provide a consistent explanation of contract formation, the intertemporal structure of labor markets, the absence of ex post market clearing, and thus of unemployment in a contractual setting. Self-fulfilling equilibria are described in which low-productivity firms lay off some workers, while high-productivity firms' recruitment (search) intensity and the resulting degree of interfirm mobility are endogenous. The effects of severance pay on layoffs and mobility are identified. Finally, the market economy is shown to generate too few layoffs whenever high-productivity firms recruit new hires: without recruitment, laidoff workers are immobile, and equilibrium is constrained efficient.