Emily Beller and Michael Hout examine trends in U.S. social mobility, especially as it relates to the degree to which a person's income or occupation depends on his or her parents' background and to the independent contribution of economic growth. They also compare U.S. social mobility with that in other countries. They conclude that slower economic growth since 1975 and the concentration of that growth among the wealthy have slowed the pace of U.S. social mobility.
In measuring mobility, economists tend to look at income and sociologists, occupation. The consensus among those measuring occupational mobility is that the average correlation between the occupations of fathers and sons today ranges from 0.30 to 0.40, meaning that most variation in the ranking of occupations is independent of social origins. Those measuring income mobility tend to agree that the elasticity between fathers' and sons' earnings in the United States today is about 0.4, meaning that 40 percent of the difference in incomes between families in the parents' generation also shows up in differences in incomes in the sons' generation.
Beller and Hout show that occupational mobility increased during the 1970s, compared with the 1940s–1960s, but there is some evidence to suggest that by the 1980s and 1990s it had declined to past levels. Existing data on income mobility show no clear trends over time, but increases in economic inequality during the 1980s made mobility more consequential by making economic differences between families persist for a longer time.
In international comparisons, the United States occupies a middle ground in occupational mobility but ranks lower in income mobility. Researchers have used the variation in mobility to study whether aspects of a country's policy regime, such as the educational or social welfare systems, might be driving these results. There is as yet, however, no scholarly consensus about the sources of cross-national differences in mobility.