Knowledge that Transforms

Reinforcement learning and stochastic fictitious play are apparent rivals as models of human learning. They embody quite different assumptions about the processing of information and optimization. This paper compares their properties and finds that they are far more similar than were thought. In particular, the expected motion of stochastic fictitious play and reinforcement learning with experimentation can both be written as a perturbed form of the evolutionary replicator dynamics. Therefore they will in many cases have the same asymptotic behavior. In particular, local stability of mixed equilibria under stochastic fictitious play implies local stability under perturbed reinforcement learning. The main identifiable difference between the two models is speed: stochastic fictitious play gives rise to faster learning. Copyright The Econometric Society 2002.

We construct and estimate an equilibrium search model with on–the–job–search. Firms make take–it–or–leave–it wage offers to workers conditional on their characteristics and they can respond to the outside job offers received by their employees. Unobserved worker productive heterogeneity is introduced in the form of cross–worker differences in a “competence” parameter. On the other side of the market, firms also are heterogeneous with respect to their marginal productivity of labor. The model delivers a theory of steady–state wage dispersion driven by heterogenous worker abilities and firm productivities, as well as by matching frictions. The structural model is estimated using matched employer and employee French panel data. The exogenous distributions of worker and firm heterogeneity components are nonparametrically estimated. We use this structural estimation to provide a decomposition of cross–employee wage variance. We find that the share of the cross–sectional wage variance that is explained by person effects varies across skill groups. Specifically, this share lies close to 40% for high–skilled white collars, and quickly decreases to 0% as the observed skill level decreases. The contribution of market imperfections to wage dispersion is typically around 50%.

This article presents evidence on the relationship between compensation ratios and spans of control within hierarchical organizations. We find that compensation ratios are lower than span of control at any position within the hierarchy, which is consistent with an elasticity of compensation to a number of subordinates lower than one. Managers’ human capital endowments determine a significant part of the salary differences throughout hierarchical levels, as predicted by models of talent allocation in hierarchies. Differences in the size of firms should be attributed more to differences in their number of hierarchical levels than to variations in the span of control.

Happiness is generally considered to be an ultimate goal in life; virtually everybody wants to be happy. The United States Declaration of Independence of 1776 takes it as a self-evident truth that the “pursuit of happiness” is an “unalienable right”, comparable to life and liberty. It follows that economics is – or should be – about individual happiness. In particular, the question is how do economic growth, unemployment and inflation, as well as institutional factors such as good governance, affect individual well-being? In addition to this intrinsic interest, there are three major reasons for economists to consider happiness. The first is economic policy. At the micro-level, it is often impossible to make a Pareto-optimal proposal, because a social action entails costs for some individuals. Hence an evaluation of the net effects, in terms of individual utilities, is needed. On an aggregate level, economic policy must deal with trade-offs, especially those between unemployment and inflation. Using happiness data for twelve European countries and the period 1975 to 1991, it has (cautiously) been calculated that a one percentage point increase in the unemployment rate is marginally compensated for by a 1.7 percentage point decrease in inflation (Rafael Di Tella, Robert MacCulloch, and Andrew Oswald 2001). This result significantly deviates from the “misery index ” which, for lack of information, has simply been defined as the sum of the percent unemployment rate and the percent annual inflation rate. Another trade-off that can be

McMillan and three anonymous referees for helpful comments, and to the National Institutes on Public opinion surveys uniformly show low support for medical care systems in developed countries. The longstanding conflict between equal access to care and efficient service provision partly explains this dissatisfaction. But the tradeoff is particularly acute in medical care, as new technologies developed over time have increased the cost of care and made the equity commitment even more expensive. Countries first dealt with rising costs by maintaining equal access and restricting total spending. Efficiency suffered, however. As a result, many countries are considering a move away from spending controls and towards incentive-based medical care reform.

This paper reviews the economics literature on welfare reform over the 1990s. A brief summary of the policy changes over this period is followed by a discussion of the methodological techniques utilized to analyze the effects of these changes on outcomes. The paper then critically reviews the econometric and experimental literature on caseload changes, labor force changes, poverty and income changes, and family formation changes. A growing body of evidence suggests that the recent policy changes have influenced economic behavior and well-being in a variety of ways. One particular set of "new-style" welfare programs seems to show especially promising results, with significantly increased work and earnings and reduced poverty.

This review culls noneconomic literature on education--by sociologists, anthropologists, and practitioners to present a new economic theory of students and schools. This theory elaborates two themes that have eluded economic analysis. First is the student as decision-maker whose primary motivation is her identity. Second is a conception of the school as a social institution. This framework suggests a new perspective on questions such as resource allocation and school reform. It explains why some educational policies succeed and others fail. We show how sociological variables may affect outcomes, and suggest ways economists can incorporate them into theoretical and empirical research.

We use data from a sample of child care centers to estimate the relationships between cost and child care quality, and between revenue and quality. We use a measure of child care quality, designed by developmental psychologists, that is positively associated with child development. Taking the estimated cost-quality and revenue-quality relationships as given, we estimate the objective functions of firms and compute the quality supply function. The results indicate that the supply of quality is moderately elastic with respect to price and the wages of child care center workers. Implications of the results for child care policy are discussed.