You could take a half-full approach and see this as a sign that over the past few decades, the economy at least hasn't become much more volatile for working people. But social advancement is all relative (especially in terms of public perception). Pew found that half of the people who saw their incomes decline over a ten-year period never returned to their previous income level over the following decade.

The risk of a severe income drop tended to fall especially hard on “those with no more than a high-school education, African Americans, and, especially, couples who split up”--three demographics that may often overlap, given historical household composition patterns.

The researchers noted that some gaps have narrowed over the years, but blacks remain more likely than whites to experience a sharp decline over a two-year period. On the other hand, Blacks also appeared more likely to see a significant two-year rise in their income.

Though the study doesn't show large swings in mobility along racial lines, but given the persistence of the racial wealth gap, stagnation in upward mobility could reflect the entrenchment of racial income stratification. Aside from income, people of color have historically lagged on other more complex measures of economic well-being.

In a study on socioeconomic change since the 1990s, the Economic Policy Institute concluded:

Overall, the economic condition of African Americans has worsened since 2000. Wage growth for the median black worker has stagnated, incomes and employment have declined, and poverty has increased.

Economic prospects are further dimmed by the criminalization of Black men, EPI noted, since a prison sentence is a pretty sure way to reduce income.

A separate analysis by EPI predicted that compared to the 1981 recession, the current economic crisis will result in a larger growth in unemployment for Black workers over a 16-month period. And between 2007 and 2010, poverty among Black children will grow by nearly 18 percentage points—about twice the growth rate for all children.

On an uneven playing field, even when “mobility” holds steady over time, those at the bottom always face a steeper climb and a harder fall. In good times and bad, entrenched inequality remains a stubborn fixture of the American workforce.

Image: Tim Robinson / NY Times