6,322 research outputs found
Selection, Investment, and Women's Relative Wages Since 1975
In theory, growing wage inequality within gender should cause women to invest more in their market productivity and should differentially pull able women into the workforce, thereby closing the measured gender gap even though women's wages might have grown less than men's had their behavior been held constant. Using the CPS repeated cross-sections between 1975 and 2001, we use control function (Heckit) methods to correct married women's conditional mean wages for selectivity and investment biases. Our estimates suggest that selection of women into the labor market has changed sign, from negative to positive, or at least that positive selectivity bias has come to overwhelm investment bias. The estimates also explain why measured women's relative wage growth coincided with growth of wage inequality within-gender, and attribute the measured gender wage gap closure to changing selectivity and investment biases, rather than relative increases in women's earning potential. Using PSID waves 1975-93 to control for the changing female workforce with person-fixed effects, we also find little growth in women's mean log wages. Finally, we make a first attempt to gauge the relative importance of selection versus investment biases, by examining the family and cognitive backgrounds of members of the female workforce. PSID, NLS, and NLSY data sets show how the cross-section correlation between female employment and family/cognitive background has changed from "negative" to "positive" over the last thirty years, in amounts that might be large enough to attribute most of women's relative wage growth to changing selectivity bias.
Household vs. Personal Accounts of the U.S. Labor Market, 1965-2000
The empirical labor supply literature includes some simple aggregate studies, and some individual-level studies explicitly accounting for heterogeneity and the discrete choice, but sometimes leaving open the ultimately aggregate questions that motivated the study. As a middle ground, we construct household-based measures of labor supply by within-household aggregating answers to the usual weeks and hours worked questionnaire items. Household (H) measures are substantially different than the more familiar person (P) measures: H employment rates are relatively higher, with little trend, and relatively little fluctuations. From the H point of view, essentially all aggregate hours trends and fluctuations can be attributed to changes on the intensive' margin and not the extensive' margin a characterization that is opposite of that derived from P measures. The cross-H distribution of hours is richer, and less spiked, than the cross-P distribution. Labor supply is more wage elastic from an H point of view.
The Closing of the Gender Gap as a Roy Model Illusion
Rising wage inequality within-gender since 1975 has created the illusion of rising wage equality between genders. In the 1970's, women were relatively equal (to each other) in terms of their earnings potential, so that nonwage factors may have dominated female labor supply decisions and nonworking women actually had more earnings potential than working women. By 1990, wages had become unequal enough that they dominated nonwage factors, so that nonworking women tended to be the ones with less earnings potential, and the wage gap between workers and nonworkers was large. Accounting for the growing selection bias using both parametric and semi-parametric versions of the Roy model, we show how the earning power of the median woman has not caught up to the earning power of a median man, even while the earning power of the median working woman has. As an illustration, we give some attention to wives with advanced degrees -- they have high and stable labor force participation rates -- and show how their measured wages have grown at about the same rate as those of men with advanced degrees.
CO2 laser transoral laser microsurgery of head and neck cancer: lessons learned over ten years
Autocorrelation of Random Matrix Polynomials
We calculate the autocorrelation functions (or shifted moments) of the
characteristic polynomials of matrices drawn uniformly with respect to Haar
measure from the groups U(N), O(2N) and USp(2N). In each case the result can be
expressed in three equivalent forms: as a determinant sum (and hence in terms
of symmetric polynomials), as a combinatorial sum, and as a multiple contour
integral. These formulae are analogous to those previously obtained for the
Gaussian ensembles of Random Matrix Theory, but in this case are identities for
any size of matrix, rather than large-matrix asymptotic approximations. They
also mirror exactly autocorrelation formulae conjectured to hold for
L-functions in a companion paper. This then provides further evidence in
support of the connection between Random Matrix Theory and the theory of
L-functions
Validating maps from single particle electron cryomicroscopy
Progress in single particle cryo-EM, most recently due to the introduction of direct detector devices, has made the high-resolution structure determination of biological assemblies smaller than 500kDa more routine, but has also increased attention on the need for tools to demonstrate the validity of single particle maps. Although map validation is a continuing subject of research, some consensus has been reached on procedures that reduce model bias and over-fitting during map refinement as well as specific tests that demonstrate map validity. Tilt-pair analysis may be used as a method for demonstrating the consistency at low resolution of a map with image data. For higher-resolution maps, new procedures for more robust resolution assessment and for validating the refinement of atomic coordinate models into single particle maps have been developed
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