Mother or market? Effects of maternal employment on the intellectual ability of 4-year-old children.

This article uses the 1986 Children of the National Longitudinal Survey of Youth data set to investigate the impact of maternal employment on children's intellectual ability, as measured at the age of 4 by using the Peabody Picture Vocabulary Test (PPVT). Results from multivariate regression analysis show a statistically significant adverse effect of mother's employment on children's intellectual ability, but only for boys in higher income families. Furthermore, the negative impact was related to the timing of maternal employment: employment during the boys' infancy had a statistically significant negative effect on PPVT scores at the age of 4. This pattern was not found for girls, for children in low-income families, or for families in which mothers resumed their employment after the child's first year of life. The impact of other demographic trends in recent years--declining fertility and rising marital instability--are also investigated. The results show an adverse effect of the presence of other siblings on children's PPVT scores; but holding family income constant, the effect of the parents' marital status on children's intellectual ability is not statistically significant. In addition, several family background factors are highly correlated with children's test scores.