As the super-wealthy have been sucking in more wealth since Repugs/conservatives got their Class War rolling with St Ronnie, income mobility has declined for the 30 years.
In short, income mobility is falling faster at the bottom of the ladder than at the top. And the poorer you get, the more likely you’re going to stay that way.
http://www.bnet.com/blog/financial-b...eam-fades/1160
http://www.bos.frb.org/economic/wp/wp2009/wp0907.pdf
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So if you're born high, you usually do well.
If you born low, you tend to stay low, more and more.
As the VRWC/corporate war on employees, unions continues to be won, winner take all, employees and household income has stagnated for 30 years.