William Julius Wilson has argued convincingly that increasing levels of nonmarriage and female-headed households are a manifestation of the high levels of economic dislocation experienced by lower-class black men in recent decades.' When joblessness is combined with high rates of incarceration and premature mortality among black men, it becomes clearer that there are fewer marriageable black men relative to black women, men who are able to provide the economic support needed to sustain a family. While joblessness is a reasonable explanation for the growth of female headed families among lower-class blacks, joblessness does not explain why upper-class blacks, for whom joblessness is not a problem, also have high rates of family-formation problems and female-headed household.
The post-World War I1 mass migration of blacks to inner city areas, particularly in the North, presaged their family formation problems because it both facilitated the civil rights mobilization and made the inner-city residents vulnerable to postindustrial changes in the economy that transformed the opportunity structure of the inner city. While urbanization and economic change have created adverse job market conditions for lower-class blacks, the civil rights revolution and affirmative action programs have opened up opportunities for upper-class blacks. Ironically, it may be that the economic uncertainty inherent in the rapid upward mobility experienced by upper-class blacks has generated high levels of marital instability and female-headed families among that group. Hence perhaps the unprecedented levels of economic uncertainty in the postwar era are a major cause of family-formation problems for both upper- and lower class blacks. How does economic uncertainty affect family-formation behavior? In general, uncertainty affects the sense of predictability of life decisions-the sense of being