Using data from the first 2 phases of the NICHD Study of Early Child Care, we examine the links between maternal employment in the first 12 months of life and cognitive, social, and emotional outcomes for children at age 3, at age 4.5, and in first grade. Drawing on theory and prior research from developmental psychology as well as economics and sociology, we address 3 main questions. First, what associations exist between 1st year maternal employment and cognitive, social, and emotional outcomes for children in the first seven years of life? Second, to what extent do any such associations vary by the child's gender and temperament or the mother's occupation? Third, to what extent do mother's earnings, the home environment (maternal depressive symptoms, sensitivity, and HOME scores), and the type and quality of child care mediate or offset any associations between 1st-year employment and child outcomes, and what is the net effect of 1st-year maternal employment once these factors are taken into account?

We compare families in which mothers worked full time (55%), part time (23%), or did not work (22%) in the first year. Our main results pertain to non-Hispanic White children (N = 900) although we also carry out some analyses for a small sample of African-American children (N = 113). Our findings provide new insight as to the net effects of 1st-year maternal employment as well as the potential pathways through which associations between 1st-year maternal employment and later child outcomes, where present, come about. Our structural equation modeling results indicate that, on average, the associations between 1st-year maternal employment and later cognitive, social, and emotional outcomes are neutral because negative effects, where present, are offset by positive effects. These results confirm that maternal employment in the 1st year of life may confer both advantages and disadvantages and that for the average non-Hispanic White child those effects balance each other.

Jeanne Brooks-Gunn is the Virginia and Leonard Marx Professor of Child Development and Education at Teachers College and the College of Physicians and Surgeons at Columbia University, and she directs the National Center for Children and Families (http: //www.policyforchildren.org). She is interested in factors that contribute to both positive and negative outcomes across childhood, adolescence, and adulthood, with a particular focus on key social and biological transitions over the life course. She designs and evaluates intervention programs for children and parents (Early Head Start, Infant Health and Development Program, Head Start Quality Program). Other large-scale longitudinal studies include the Fragile Families and Child Well-being Study and the Project on Human Development in Chicago Neighborhoods (co-PI of both). She is the author of 4 books and over 500 publications. She has been elected into the Institute of Medicine of the National Academies and she has received life-time achievement awards from the Society for Research in Child Development, the American Academy of Political and Social Science, the American Psychological Society, the American Psychological Association, and the Society for Research on Adolescence.

Wen-Jui Han is an associate professor at the Columbia University School of Social Work. Her research focuses on the areas of child care, parental employment, and child well-being, paying particular attention to links between parental work schedules and child well-being. Her recent research has also examined the developmental experiences of U.S. young children in immigrant families with particular attention on how school environments and children's language backgrounds may shape these children's well-being. Her work has been published in leading academic journals including the American Journal of Public Health, Child Development, Demography, Developmental Psychology, Early Childhood Research Quarterly, Journal of Marriage and Family, and Journal of Adolescence.

Jane Waldfogel is a professor of social work and public affairs at Columbia University School of Social Work and a visiting professor at the Centre for Analysis of Social Exclusion at the London School of Economics. She has written extensively on the impact of public policies on child and family wellbeing. Her current research includes studies of work-family policies, fragile families and child well-being, poverty, and inequality in early child outcomes across countries. Waldfogel's publications include five books and over 100 articles and book chapters. Her work has been published in leading academic journals including the American Economic Review, American Educational Research Journal, American Sociological Review, Child Development, Demography, Developmental Psychology, Economic Journal, Journal of Economic Perspectives, Journal of Policy Analysis and Management, Journal of Human Resources, Journal of Labor Economics, Journal of Population Economics, Monthly Labor Review, and Pediatrics.