Have family income mobility patterns changed?

We examine the mobility of individuals in the United States based on equiva lent family income-that is, total income of all family members adjusted for family size according to the equivalence scale implicit in the U.S. povert y line. Our analysis, which tracks movements across quintiles, centers on f our questions: How much movement is there across the family income distribu tion? How has this mobility changed over time? To what extent are the movem ents attributable to factors related to changes in family composition versu s events in the labor markets? In light of major socioeconomic changes occu rring in the quarter-century under study, have the determinants of mobility changed over time? Our findings indicate that mobility rates in the 1980s differed little from those in the 1970s. However individuals in families he aded by a young person or a person without a college education were less li kely to experience upward mobility in the 1980s than in the 1970s.