Data from the Panel Study of Income Dynamics, the November 1989 Current Population Survey, and the National Longitudinal Study of Women suggest that women with sisters may have completed less schooling than women without sisters. This hypothesis follows a long tradition of theories about the effects of sibling number and configuration. There is relatively weak evidence for this hypothesis in the analysis on which the findings are based. Analyses of the effects of sibling gender composition on educational attainment among cohorts of women in the Occupational Changes in a Generation Survey, the Survey of Income and Program Participation, and the National Survey of Families and Households offer no support for this hypothesis or for other related hypotheses about the effects of the gender composition of sibships.

Robert M. Hauser is a professor of sociology at the Center for Demography and Ecology University of Wisconsin-Madison. Hsiang-Hui Daphne Kuo is an assistant professor of sociology at the University of Washington. This research was supported by grants from the National Institute on Aging (AG-9775) and the Vilas Estate Trust. It was carried out using facilities of the Center for Demography and Ecology at the University of Wisconsin-Madison, for which core support comes from the National Institute of Child Health and Human Development. Statistical tabulation and estimation were performed using SPSS and LIMDEP under VMS. All of the data used herein are in the public domain. The data used in this article can be obtained beginning November, 1998 through October, 2001 from the senior author at the address below. The opinions expressed herein are those of the authors. The authors thank Kathryn Wilson for the suggestion that effects of gender composition might vary across cohorts. Correspondence should be directed to Robert M. Hauser, Department of Sociology, University of Wisconsin-Madison, 1180 Observatory Drive, Madison, Wisconsin 53706; e-mail hauser@ssc.wisc.edu.