Knowledge that Transforms

This article examines the responses of black and white workers to their employer's relocation from downtown Detroit to suburban Dearborn. Estimates of move and quit probabilities demonstrate that white employees whose commutes lengthened because of the relocation were more likely to move, but no more likely to quit, than white employees whose commute shortened. Black employees whose commutes lengthened were more likely to both move and quit in the wake of the relocation. In effect, the restrictions on black residential choice imposed by segregation forced approximately 11.3% of black workers to quit in the wake of the relocation.

This article investigates how human capital investment, labor turnover, and wages are jointly determined when the current employer knows more about a worker's productivity than potential employers. Results derived are quite different from, or unexplored by, the standard human capital theory. The authors show that the information asymmetry can cause an externality distortion in human capital investment because higher productivity due to the investment may not be recognized by the market. The investment level increases in the degree of firm specificity of human capital. The underinvestment problem is more severe when human capital is general than when it is firm-specific.

This article presents evidence that internal mobility, defined as a promotion or other position change, is an important source of wage growth. It accounts for approximately 15% of wage growth over the life cycle for white and black men, but less for women. The incidence of promotions and other position changes appears tied to the wage level: better paid workers are more likely to be promoted. The life-cycle incidence of internal mobility looks similar to that for conventionally defined job mobility. Most moves are made early in the career; mobility declines both with time in position, and with experience.

Risk aversion enters many theoretical models of human capital investment, but attitudes toward risk have not been incorporated in empirical models of human capital investment. This article develops a model of the joint investment in financial wealth and human wealth to show that human capital investment is an inverse function of the degree of relative risk aversion. Using data from the Survey of Consumer Finances, I find that wage growth is positively correlated with preferences for risk taking. More-educated individuals are also more likely to be risk takers, thus risk taking explains a portion of the returns to education.

This article analyzes the choice between internal promotion and external recruitment within the framework of an economic contest. Opening up the competition for a position to external candidates reduces the chance of promotion for existing workers and therefore their incentive to work. Increasing the prize for winning can maintain incentives but is limited by moral hazard and potentially disruptive office politics. Alternatively, a competitive handicap can be awarded to existing workers to boost their chances. This strategy is consistent with the general observation that an external candidate is recruited only if she is significantly superior to the internal contestants.

A firm's decision to contract out for business support services may be influenced by the wage and benefit savings it could realize, the volatility of its output demand, and the availability of specialized skills possessed by the outside contractor. Analysis of newly available establishment-level data shows that all three of these factors help to explain observed contracting behavior. The reported empirical findings are relevant both for understanding the recent growth in business support service contracting and for understanding firms' relationships with their own employees.

This article begins by reviewing the main body of evidence about the effectiveness of resources devoted to schools. It then discusses some of the central implications for policy and for economic research. The implications for educational policy draw heavily on the discussion of the Panel one the Economics of Education Reform (PEER), a group of economists who met over a four-year period to discuss economic aspects of educational investments. Those recommendations are only sketched here, but are detailed in its report, Making Schools Work (Hanushek and others, 1994).

Private Truths, Public Lies is a splendid book. It tackles a long list of interesting and important questions that have been discussed at length, and largely unsuccessfully, by scholars from each of the social sciences. Kuran blends the insights of economics, psychology, sociology, and political science into a behavioral model that moves the discussion forward on many fronts. His may not be the model that many traditional economists might have chosen, but it is one that most can live with.

Statistical significance as used in economics has weak theoretical justification. In particular it merges statistical and substantive significance. The 182 papers using regression analysis in the American Economic Review in the 1980s were tested against 19 criteria for the accepted use of statistical significance. Most, some three-quarters of the papers, did poorly. Likewise, textbooks in econometrics do not distinguish statistical and economic significance. Statistical significance should not be the focus of empirical economics.