the american dream

[...] prime-age families are working in the paid labor market now relative to the labor supply of earlier cohorts. In that sense, today's families are running faster yet gaining less ground.

These mobility and cohort analyses consistently reveal some degree of income mobility and growth in America. By no means does the United States have a totally stagnant, immobile society, where people are stuck in their place in the income scale, decade after decade. But neither are they moving that far from where they start. Most who start at the top and the bottom are there a decade later. Most who start out in the middle-class are still in or near the middle-class a decade later; of those who start out in the middle fifth, about 75% are in one of the middle three-fifths a decade later.

Moreover, the rate of mobility has not changed over time. The data [...] cover roughly the last two decades, but the last edition of this book took the analysis back yet another decade [...] and showed the same result. This finding is important in the context of the inequality debate. It is true that greater mobility can offset higher inequality. But that is not happening in America.

Lawrence Mishel, The State of Working America 2008-2009