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...