We use longitudinal data to examine the relationship between parenthood, wages, and hours worked for married men and women. We find evidence of negative selection into parenthood, substantial child-related reallocations of time within the household, and heterogeneity in the effects of children on household behavior. In households in which the wife experiences an interruption in employment, mothers' wages and hours worked fall, while fathers' hours and wages increase. In households in which the mother remains continuously attached to the labor force, however, there is no evidence of a wage decline for mothers, and the hours worked by fathers decrease substantially. (C) 2000 Elsevier Science B.V. All rights reserved. JEL classification: D10; J13; J22.