The study is impressive work, and I would encourage our Philadelphia readers to put it on their list of weekend long reads. As always, context matters. While there is much that is good in this study, how best to link it into the city's economic and social policy is going to be a matter of intense debate. So take a moment now to read up on what this study does and doesn’t say.
The study brought to mind Michael Smerconish's recent Inquirer column that cites another study identifying marriage as a factor in growing income inequality — specifically, the marriage of highly educated people to other highly educated people (resulting in higher incomes). The study is a great example of what Larry Mishel at the Economic Policy Institute (EPI) calls "misdirection" (more on that later). The essential problem is that it identifies demographic trends, rather than changes in the distribution of income, as the reason we have rising income inequality.