Here is a new graph that covers territory I have covered in numerous ways before. These are simple standard deviations of relative median home price and relative median income for the 100 largest MSAs in the US. (For each year, US median = 1) In other words, if all cities had the same median income and home price, these measures would be zero. As cities diverge from one another, these measures increase.
The rise in home prices during the boom was the result of a bidding war to get into artificially exclusive cities where incomes are higher. We "fixed" the housing market by destroying the middle class mortgage market. Since this "fix" didn't address the fundamental problem, we have actually made the fundamental problem worse. So, the distribution of incomes has become worse since the bust began.
The "fix" did temporarily bring down the variance in home prices, but it couldn't really permanently do that. So, after the initial dislocation, the long term pressure on localized home prices re-asserted itself, and now the variance of home prices among MSAs is higher than ever.