Women's occupational attainment: The effects of work interruptions, self-selection, and unobserved characteristics

This paper addresses specification issues concerning the estimation of women's occupational attainment. Attainment models generally assume independence of error terms across equations, and whether this assumption is made or whether correlation of error terms is assumed is found to have important substantive implications, particularly with respect to education. While education affects first-job status, when first-job status is controlled, education has no significant effect on current attainment. A woman's first-job status appears, then, to be of major importance, and if she enters a job for which she is overqualified, education may not be relied upon to improve her occuppational status in the future. As in the analysis of earnings, it is important not only to include years of experience, as is usual in attainment models, but to include whether a recent work interruption has occurred. This is a significant and important variable in both the correlated and uncorrelated errors models, but the uncorrelated errors model appears to understate the magnitude of effect.     

One for Nine: The Shared Cataloging Program of the California Digital Library

Abstract

In 1999, the California Digital Library (CDL) began a new cooperative venture, the Shared Cataloging Program, to improve access to its growing collection of electronic resources. Now known within the University of California (UC) as the SCP, the Shared Cataloging Program, based at UC San Diego, distributes ready-to-use cataloging records for all electronic titles licensed by the CDL to each of the other eight (soon to be nine) physical UC campuses. The SCP is the result of an intensive systemwide planning process fostered by a desire for an innovative approach to providing traditional bibliographic access to large numbers of electronic resources. It was launched out of pragmatic necessity along with an institutional commitment to the cooperative ideals of labor-savings, experimentation, and the search for “best practices.” This article will describe its genesis, current operation, one library's use of the records, and issues for future development. Serials Review 2002; 28:4–12.     

Robust multivariate analysis of variability

A general testing procedure is proposed to multivariately test for equality of p variances among k groups. The procedure applies a multivariate analysis of variance on an appropriate measure of spread for the uncensored original observations. Three such measures of spread are compared in a simulation experiment which considered two and three variables with equal and unequal sample sizes for the null and alternative hypotheses for Gaussian, Student's t (8, 12, and 20 degrees of freedom) and gamma (α=2,4,6 and 10) distributions . The likelihood ratio test (Box, 1949) was included in the above simulations. The results suggest that if one chooses a measure of spread appropriate for the distribution of the original observations, the proposed MANOVA-based testing procedure is robust and reasonably powerful. Using this procedure for the normal distribution, similar power was observed to that of the likelihood ratio test when the variables were uncorrelated or had little positive correlation.