Endogenous On The Job Search And Frictional Wage Dispersion

This paper addresses the large degree of frictional wage dispersion in US data. The standard job matching model without on-the-job search cannot replicate this pattern. With on-the-job search, however, unemployed job searchers are more willing to accept low wage offers since they can continue to seek for better employment opportunities. This explains why observably identical workers may be paid very differently. Therefore, we examine the quantitative implications of on-the-job search in a stochastic job matching model. Our key result is that the inclusion of variable on-the-job search increases the degree of frictional wage dispersion by an order of a magnitude.

Standard search and matching models of equilibrium unemployment, once properly calibrated, can generate only a small amount of frictional wage dispersion, i.e., wage differentials among ex-ante similar workers induced purely by search frictions. We derive this result for a specific measure of wage dispersion -- the ratio between the average wage and the lowest (reservation) wage paid. We show that in a large class of search and matching models this statistic (the "mean-min ratio") can be obtained in closed form as a function of observable variables (i.e., the interest rate, the value of leisure, and statistics of labor market turnover). Various independent data sources suggest that actual residual wage dispersion (i.e., inequality among observationally similar workers) exceeds the model's prediction by a factor of 20. We discuss three extensions of the model (risk aversion, volatile wages during employment, and on-the-job search) and find that, in their simplest versions, they can improve its performance, but only modestly. We conclude that either frictions account for a tiny fraction of residual wage dispersion, or the standard model needs to be augmented to confront the data. In particular, the last generation of models with on-the-job search appears promising.

Dale T. Mortensen and Christopher A. Pissarides are the recipients (with Peter Diamond) of the Nobel memorial Prize in Economics 2010. They have made path-breaking contributions to the analysis of markets with search and matching frictions, which account for much of the success of job searchtheory and the flows approach in becoming a leading tool for microeconomic and macroeconomic analysis of labor markets. Both scientists have gained groundbreaking insights through individual as well as joint research. Consequently, this volume not only features several papers which helped shape theequilibrium search model, including some early contributions which have initiated the research on what is known today as the search and matching model of the labor market, but it also presents a joint paper by the IZA Prize Laureates, which is a complete statement of the equilibrium search andmatching model with endogenous job creation and job destruction.As part of the IZA Prize Series, the book presents a selection of their most important work which has highly enriched research on unemployment as an equilibrium phenomenon, on labor market dynamics, and on cyclical adjustment.

Standard search and matching models of equilibrium unemployment, once properly calibrated, can generate only a small amount of frictional wage dispersion, i.e., wage differentials among ex-ante similar workers induced purely by search frictions. We derive this result for a specific measure of wage dispersion -- the ratio between the average wage and the lowest (reservation) wage paid. We show that in a large class of search and matching models this statistic (the "mean-min ratio") can be obtained in closed form as a function of observable variables (i.e., the interest rate, the value of leisure, and statistics of labor market turnover). Various independent data sources suggest that actual residual wage dispersion (i.e., inequality among observationally similar workers) exceeds the model's prediction by a factor of 20. We discuss three extensions of the model (risk aversion, volatile wages during employment, and on-the-job search) and find that, in their simplest versions, they can improve its performance, but only modestly. We conclude that either frictions account for a tiny fraction of residual wage dispersion, or the standard model needs to be augmented to confront the data. In particular, the last generation of models with on-the-job search appears promising.

A theoretical and empirical examination of wage differentials findsthat traditional theories of competition do not explain why workers with identical skills are paid differently.