The Wage Penalty for Motherhood

Motherhood is associated with lower hourly pay, but the causes of this are not well understood. Mothers may earn less than other women because having children causes them to (1) lose job experience, (2) be less productive at work, (3) trade off higher wages for motherfriendly jobs, or (4) be discriminated against by employers. Or the relationship may be spurious rather than causal; women with lower earning potential may have children at higher rates. Using 1982-1993 NLSY data, we examine the motherhood penalty with fixed-effects models chosen to avoid spuriousness. We find penalties of 7 percent per child. Penalties are larger for married women. We show that women with (more) children have less job experience; after controlling for this, a penalty of 5 percent per child remains. We examine whether potentially mother-friendly characteristics of the jobs held by mothers explain any of the penalty, but find little evidence of this beyond the tendency of more mothers to work part-time. The portion of the motherhood penalty we cannot explain probably results from effects of motherhood on productivity and/or from employers discrimination against mothers. While the benefits of mothering diffuse widely, to the employers, neighbors, friends, spouses, and children of the adult who previously received the mothering, the costs are borne disproportionately by mothers.