Women's work, sibling competition and children's school performance
基于美国小样本面板数据，发现学前阶段同胞数量（尤其是年龄相近的兄弟）对儿童小学学业表现有显著负面影响，而母亲减少市场工作、增加育儿时间可缓解这一劣势，但全职工作对母亲收入增长重要，因此女性面临家庭与市场的权衡。
This research offers an interpretation of the relationship between fertility, child spacing, family resources, and market work by mothers, and the subsequent cognitive skills of grade schoolers as reported by their teachers. First, an approach to fertility as the outcome of a deliberate choice process is developed, and then empirical evidence from a small panel of U.S. households first interviewed in 1975-76 when they had preschool children is presented. In a 1981-82 reinterview, a supplementary project was that of obtaining teacher ratings of school performance of individual children. Large family size, as measured by the number of siblings of given age and sex in the household during preschool years (in 1975-76), has an important, negative impact on the child's subsequent grade-school performance. Boy siblings in nearby age ranges have the most negative impact on performance while teenage siblings of either sex have no systematic adverse effect. Parental resources, as measured by income, education, child-care time, and a mother's reduced market time are associated with greater cognitive skills, and can offset the apparent disadvantage of having siblings in nearby age intervals. There appears to be a significant tradeoff between a market career and a home career for women. Women who have more children spaced over wider age intervals and who devote more time to child care and less to market work presumably get more benefits from their home career in the form of enhanced child development. On the other hand, full-time market work (i.e., hours in the labor market for pay) is important for earnings growth of the mother (Mary Corcoran, Greg Duncan, and Michael Ponza, 1983), and family income has a favorable effect on school performance, so the apparent choices facing women are more equivocal.