New Market Power Models and Sex Differences in Pay

In the context of certain general equilibrium search models, it is possible to infer the elasticity of labor supply to the firm from the elasticity of the quit rate with respect to the wage. We use this framework to estimate the elasticity of labor supply for men and women workers at a chain of grocery stores operating in the southwestern United States, identifying separation elasticities from differences in wages and separation rates across different job titles within the firm. We estimate elasticities of labor supply to the firm of about 2.7 for men and about 1.5 for women, suggesting significant wage-setting power for the firm. Since women have lower elasticities of labor supply to the firm, a Robinson-style monopsony model might explain lower relative pay of women in the grocery industry. The wage gaps we observe among workers in US retail grocery stores are close to what the monopsony model predicts for the elasticities we have estimated.monopsony papers, labor supply, grocery stores, elasticity

Sex differences in pay in a new monopsony model of the labor market

We use a simple framework, adopted from general equilibrium search models, to estimate the extent to which monopsony power (or labor market frictions) can account for gender differences in pay, using data from a chain of regional grocery stores. In this framework, the elasticity of labor supply to the firm can be inferred from estimates of the elasticity of the separation rate with respect to the wage. We identify elasticities of separation from differences in wages and separation rates across job titles and across different years. We estimate elasticities of labor supply to the firm of about 3.5 for men and about 2.7 for women, suggesting significant wage-setting power for the firm. The differences in estimated elasticities of labor supply predict wage differences that are close to the observed male/female wage differences at the firm

Intrafirm Mobility and Sex Differences in Pay

In this paper we analyze eight years of employment data of a regional grocery store chain in the U.S. The data include job titles, wage rates, and earnings for all employees. We examine initial job assignments, mobility between departments, and mobility into supervisory and management positions in the firm. We model the flows of individuals between different departments and jobs within the firm as a Markov process. The estimated transition probabilities imply that expected seniority is greater for women. We find a pattern of intrafirm mobility and initial job assignment that generally penalizes women, even after taking account of individuals' characteristics

Auswirkungen wählbarer Selbstbehalte in der Krankenversicherung: Lehren aus der Schweiz?

In diesem Papier wird diskutiert, ob die Einführung wählbarer Selbstbehalte in der Gesetzlichen Krankenversicherung einen sinnvollen Weg zur Kosteneinsparung im Gesundheitswesen darstellt. Ausgehend von Befunden aus dem schweizerischen Gesundheitssystem, das solche wählbaren Selbstbehalte in der obligatorischen Grundversicherung seit 1996 kennt, wird argumentiert, dass die Wahlmöglichkeit des Selbstbehalts keinen starken Einfluss auf das Patientenverhalten zu haben scheint. Der Großteil der beobachteten Reduktion der Anzahl der Arztbesuche bei Versicherten mit höheren Selbstbehalten ist durch Selbstselektion zu erklären. Gesündere Versicherte oder Versicherte, die aufgrund ihrer Präferenzen weniger medizinische Leistungen in Anspruch nehmen, wählen höhere Selbstbehalte. Eine durch die gewählte höhere Selbstbeteiligung induzierte Verhaltensänderung in Richtung einer sparsameren Inanspruchnahme des Gesundheitswesens ist kaum festzustellen. Soll trotzdem eine Wahlmöglichkeit bei Selbstbehalten in Deutschland eingeführt werden, gilt es die Systemunterschiede zwischen der Individualversicherung (CH) und der Familienversicherung (D) zu beachten. Die Einführung von nicht wählbaren Kostenbeteiligungen der Patienten scheint leichter durchsetzbar, da die Selbstselektion von Gesunden und Kranken in verschiedene Versicherungskontrakte, die vielfach als unsolidarisch empfunden wird, nicht auftreten kann

Unexplained Gaps and Oaxaca-Blinder Decompositions

We analyze four methods to measure unexplained gaps in mean outcomes: three decompositions based on the seminal work of Oaxaca (1973) and Blinder (1973) and an approach involving a seemingly naive regression that includes a group indicator variable. Our analysis yields two principal findings. We show that the coefficient on a group indicator variable from an OLS regression is an attractive approach for obtaining a single measure of the unexplained gap. We also show that a commonly-used pooling decomposition systematically overstates the contribution of observable characteristics to mean outcome differences when compared to OLS regression, therefore understating unexplained differences. We then provide three empirical examples that explore the practical importance of our analytic results

A Comparison of Simple Mass Estimators for Galaxy Clusters

High-resolution N-body simulations are used to investigate systematic trends in the mass profiles and total masses of clusters as derived from 3 simple estimators: (1) the weak gravitational lensing shear field under the assumption of an isothermal cluster potential, (2) the dynamical mass obtained from the measured velocity dispersion under the assumption of an isothermal cluster potential, and (3) the classical virial estimator. The clusters consist of order 2.5e+05 particles of mass m_p \simeq 10^{10} \Msun, have triaxial mass distributions, and significant substructure exists within their virial radii. Not surprisingly, the level of agreement between the mass profiles obtained from the various estimators and the actual mass profiles is found to be scale-dependent. The virial estimator yields a good measurement of the total cluster mass, though it is systematically underestimated by of order 10%. This result suggests that, at least in the limit of ideal data, the virial estimator is quite robust to deviations from pure spherical symmetry and the presence of substructure. The dynamical mass estimate based upon a measurement of the cluster velocity dispersion and an assumption of an isothermal potential yields a poor measurement of the total mass. The weak lensing estimate yields a very good measurement of the total mass, provided the mean shear used to determine the equivalent cluster velocity dispersion is computed from an average of the lensing signal over the entire cluster (i.e. the mean shear is computed interior to the virial radius). [abridged]Comment: Accepted for publication in The Astrophysical Journal. Complete paper, including 3 large colour figures can also be obtained from http://bu-ast.bu.edu/~brainerd/preprints

An Extension of the Blinder-Oaxaca Decomposition to Non-Linear Models

In this paper, a general Blinder-Oaxaca decomposition is derived that can also be applied to non-linear models, which allows the differences in a non-linear outcome variable between two groups to be decomposed into a part that is explained by differences in observed characteristics and a part attributable to differences in the estimated coeffcients. Departing from this general model, we show how it can be applied to different models with discrete and limited dependent variables