Ruhm, Christopher J. 2004. "Parental Employment and Child Cognitive Development." Journal of Human Resources 39(1): 155-192.

Maternal employment during the first three years of the child's life has a small deleterious effect on estimated verbal ability of three- and four-year-olds and a larger negative impact on reading and mathematics achievement of five- and six-year-olds. This study provides a more pessimistic assessment than most prior research for two reasons. First, previous analyses often control crudely for differences in child and household characteristics. Second, the negative relationships are more pronounced for the reading and mathematics performance of five- and six-year-old children than for the verbal scores of three- and four-year-olds.

Christopher J. Ruhm is a professor of economics at the University of North Carolina at Greensboro and a research associate at the National Bureau of Economic Research. He thanks Carey Borkoski for research assistance and Li Gan, Hilary Hoynes, Dan Rosenbaum, Donna Ruane Morrison, David Wildesin, and seminar participants at Case Western Reserve University, Georgetown University, the Institute for the Study of Labor, University of California at Berkeley, University of Kentucky, University of Texas, University of Virginia, University of Washington, and Vanderbilt University for helpful comments. Financial support from the University of North Carolina Greensboro, the National Science Foundation (SES-9876511), and the National Institute of Child Health and Human Development (HD38521-01A1) is gratefully acknowledged. All opinions, findings, and conclusions or recommendations are those of the author and do not necessarily reflect the views of the funding agencies. The data used in this article can be obtained beginning August 2004 through July 2007 from Ruhm.