1 1. Although employment discrimination may be a factor contributing to the earnings differential between women and men, the family specialization hypothesis suggests that women make a trade-off between earnings and working conditions complementary with their household responsibilities. As a result, women are more likely to choose discontinuous labor force participation and forego job training. The fact that the F /M earnings ratio is m uch higher for singles than for married persons with spouse present is consistent with the view that the family specialization factors have an important impact on earnings according to sex. The earnings gap between men and women probably reflects both employment discrimination and family specialization.