Michael Rosenfeld questions the boomerang narrative:
Census data show that what is really new about young adulthood is the percentage of young adults who live on their own. From 1880 to 1970 the percentage of U.S. born women in their twenties who lived on their own (not with parents and not with a husband) was always less than 15 percent. By 1980, the percentage of young adult women who lived on their own had risen to 27 percent, and to 33 percent in 1990, to 39 percent in 2000, and to 42 percent today.
The delay of marriage and the extension of singleness can make it appear as if young people are more likely to return to the parental nest. If one examines single people in their twenties, who are the people who have the option of living with their parents, the percentage who live with their parents is now about 45 percent. That may seem high but it isn't: in the past single people in their 20s nearly always lived with their parents. The Great Recession has actually had no effect whatsoever on the percentage of young adults living with their parents in the United States. This is not so surprising; the (even greater) Great Depression did not affect family structure much, and neither did the Industrial Revolution. Family structure changes slowly over time. Economic ups and downs have little effect on who lives with whom.