Does motherhood affect productivity, relative performance, and earnings?

The Ladies Professional Golf Association provides a unique setting to examine productivity differences between women with children and women without children. In this paper, productivity is directly observed (e.g., the player's golf score), unlike most studies that use wage as a proxy for productivity. Therefore, discrimination cannot be a source of observed differences in productivity between mothers and nonmothers, since the earnings of players are strictly determined by relative performance. Using panel data on women professional golfers, I find that motherhood lowers productivity. The productivity of women who eventually become mothers increases in the years before giving birth and then declines thereafter. The results support the human-capital explanation and Becker's effort hypothesis of the family gap. One further finding is that marriage increases productivity.