They focus instead on the top and bottom quintiles—but miss substantial mobility there too. Of children reared in the top quintile, 62% fell to one of the lower quintiles, including more than 9% to the bottom quintile. A significant number of the children reared in the top quintile who stayed in the top quintile as adults had incomes far greater than their parents, but statistically they could not rise out of the top quintile.
With few advantages and often trapped in failing public schools, 63% of children who grew up in bottom quintile families rose to a higher quintile, 6.1% rising all the way to the top quintile. A significant number of those who failed to rise would have been the adult children who didn’t work as public assistance soared. The share of the bottom quintile who worked fell from 68% in the parents’ generation to 36% in the children’s generation.
But even these impressive numbers understate real income mobility in America. These studies measure relative mobility by comparing the children’s income quintile then and now. Relative mobility is a zero-sum game—by definition, 20% of households are in the lowest quintile and only 20% in the highest—but income growth isn’t. The vast majority of adult children had higher real incomes than their parents. To rise out of the bottom quintile, children’s inflation-adjusted income had to increase by more than the growth of the income ceiling for the bottom quintile during the years between generations—35% in Mr. Strain’s study. Children reared in any other quintile had to see their real income as adults rise on average by roughly 50% above their parents’ income simply to avoid falling into a lower quintile than their parents. The climb to a higher quintile is steeper still.
Fortunately, data from the Strain study can be used to measure mobility in a way that takes into account the extraordinary income growth in America between the parents’ generation and the adult children’s generation. When the income of the children is compared with the inflation-adjusted income of their parents using the real income quintiles of their childhood in 1982–86 rather than the income quintiles of 2013–17, measured mobility is dramatically greater. Only 28% of children reared in the bottom quintile had adult incomes that would put them in the bottom childhood quintile, and 26% rose all the way to the childhood top quintile, which required a minimum income of only $111,416 (in 2016 dollars) for a family of four in 1982–86. A family of four with that income in 2013–17 would have been in the middle quintile based on 2013–17 income distribution.
During the 35 years of the study, adult children who worked rode up the American economic escalator as average incomes rose dramatically. Those who climbed as the escalator rose moved up faster. Those who stood still or stumbled down rose more slowly, and those who stayed off the escalator by not working missed the ride. The mobility studies shown in the chart capture the effect of climbing, stumbling and choosing not to ride, but they miss the escalator effect, which came from the growth of the American economy. Many of today’s middle-income adults have a real standard of living that would have put them in the top quintile in their parents’ era.
This incredible income mobility is measured only over one generation. Parents struggle and sacrifice to provide their children with education and opportunities they themselves lacked. Millions of parents have lived out their dreams through the achievements of their children, generation after generation. As a result, America’s real mobility is most visible over multiple generations. Many historians believe George Washington’s grandmother came to America as an indentured worker. Washington became one of the richest men in colonial America and, in the words of King George III, “the greatest man in the world.”
It is better to be born rich, brilliant and beautiful, but poor, ordinary and homely people succeed in America every day. The American dream is alive and well.