WSJ: Growing Income Equality and Mobility

Interesting editorial in today's Wall Street Journal:  Movin' On Up:  A Treasury Study Refutes Populist Hokum About "Income Inequality":

If you've been listening to Mike Huckabee or John Edwards on the Presidential trail, you may have heard that the U.S. is becoming a nation of rising inequality and shrinking opportunity. We'd refer those campaigns to a new study of income mobility by the Treasury Department that exposes those claims as so much populist hokum.

OK, "hokum" is our word. The study, to be released today, is a careful, detailed piece of research by professional economists that avoids political judgments. But what it does do is show beyond doubt that the U.S. remains a dynamic society marked by rapid and mostly upward income mobility. Much as they always have, Americans on the bottom rungs of the economic ladder continue to climb into the middle and sometimes upper classes in remarkably short periods of time.

The Treasury study examined a huge sample of 96,700 income tax returns from 1996 and 2005 for Americans over the age of 25. The study tracks what happened to these tax filers over this 10-year period. One of the notable, and reassuring, findings is that nearly 58% of filers who were in the poorest income group in 1996 had moved into a higher income category by 2005. Nearly 25% jumped into the middle or upper-middle income groups, and 5.3% made it all the way to the highest quintile. ...

The key point is that the study shows that income mobility in the U.S. works down as well as up--another sign that opportunity and merit continue to drive American success, not accidents of birth. The "rich" are not the same people over time.

The Treasury Department report is Income Mobility in the U.S. From 1996 to 2005.  The Summary is below the fold:

This study examines income mobility of individuals over the past decade (1996 through 2005) using information reported on individual income tax returns.

While many studies have documented the long-term trend of increasing income inequality in the U.S. economy, there has been less focus on the dynamism of the U.S. economy and the opportunity for upward mobility. Comparisons of snapshots of the income distribution at points in time miss this important dimension and can sometimes be misleading.

Economic historian Joseph Schumpeter compared the income distribution to a hotel where some rooms are luxurious, but others are small and shabby. Important aspects of fairness are that those in the small rooms have an opportunity to move to a better one, and that the luxurious rooms are not always occupied by the same people. The frequency with which people move between rooms is a crucial aspect of the trends in income inequality in the United States.

The key findings of this study include:

• There was considerable income mobility of individuals in the U.S. economy during the 1996 through 2005 period with roughly half of taxpayers who began in the bottom quintile moving up to a higher income group within 10 years.
• About 55 percent of taxpayers moved to a different income quintile within 10 years.
• Among those with the very highest incomes in 1996 – the top 1/100 of 1 percent – only 25 percent remained in this group in 2005. Moreover, the median real income of these taxpayers declined over this period.
• The degree of mobility among income groups is unchanged from the prior decade (1987 through 1996).
• Economic growth resulted in rising incomes for most taxpayers over the period from 1996 to 2005. Median incomes of all taxpayers increased by 24 percent after adjusting for inflation. The real incomes of two-thirds of all taxpayers increased over this period. In addition, the median incomes of those initially in the lower income groups increased more than the median incomes of those initially in the higher income groups.

The degree of mobility in the overall population and movement out of the bottom quintile in this study are similar to the findings of prior research on income mobility.