ECONOMIC

and estimates of some of these effects are given. While those omitted sourceswhich would decrease family income inequality have been growing in importanceover time, there exists no such presumption concerning the omittedsources that would increase it.Many factors, such as schooling and on-the-job training, determine theinequality of earnings among workers. Differentials in the earnings of whitesand blacks, and of males and females, are analyzed with respect to the contributionto the differential made by training and other factors that influenceproductivity. Past discrimination has contributed to current differences inproductivity because of the once widespread barriers to equivalent schoolingand on-the-job training. Because of the difficulties of measuring productivity,no conclusion could be reached about the magnitude of current labormarket discrimination against blacks or women. For the same reason it isdifficult to determine whether labor market discrimination has declined withtime, although there is a strong presumption that it has. For men, the blackwhiteearnings differential has narrowed, and much of the change may bedue to a narrowing of educational differences. The narrowing of the differentialhas been much more dramatic for black women, however, andoutside the South black women now receive a higher wage rate than whitewomen. This development is largely due to black women's greater lifetimeattachment to the labor force, and hence their greater level of experience andtraining.The differential in hourly earnings between men and women has widenedover time, and this change reflects the relative decline in education andexperience of women in the labor force. With the rapid increase in thelabor force participation of women, the female labor force has becomeincreasingly composed of recent entrants with fewer years of schooling and ofexperience. Younger women are, however, showing less tendency to withdrawfrom the labor force for a prolonged period; as the age of these cohortsincreases and they come to comprise a larger proportion of women in thelabor force, the experience and earnings differential between men andwomen should decrease.Widespread concern is felt about those whose incomes fall below a levelneeded to maintain an adequate living standard. There has been a markeddecline in poverty, as conventionally defined, from 39 million persons in1959 to 24 million persons in 1972, in large part because of economicgrowth, which increased wage rates and employment opportunities for menand women, and permitted larger social security and pension benefits. Increasinglythe poor are living in families in which there is no adult worker,and increasingly the family is headed by a female.The Federal Government has several programs—some operated on itsown, others in conjunction with the States—which are intended to decreasepoverty. Aid to Families with Dependent Children (AFDC) is themost important Federal-State program designed explicitly for poor familiesin which there is no employed male head. The 3.1 million AFDC families138