Family Structure and Inequality

At The Wall Street Journal, Robert Maranto and Michael Crouch write:

Suppose a scientific conference on cancer prevention never addressed smoking, on the grounds that in a free society you can't change private behavior, and anyway, maybe the statistical relationships between smoking and cancer are really caused by some other third variable. Wouldn't some suspect that the scientists who raised these claims were driven by something—ideology, tobacco money—other than science?

Yet in the current discussions about increased inequality, few researchers, fewer reporters, and no one in the executive branch of government directly addresses what seems to be the strongest statistical correlate of inequality in the United States: the rise of single-parent families during the past half century.
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More than 20% of children in single-parent families live in poverty long-term, compared with 2% of those raised in two-parent families, according to education-policy analyst Mitch Pearlstein's 2011 book "From Family Collapse to America's Decline." The poverty rate would be 25% lower if today's family structure resembled that of 1970, according to the 2009 report "Creating an Opportunity Society" from Brookings Institution analysts Ron Haskins and Isabel Sawhill. A 2006 article in the journal Demography by Penn State sociologist Molly Martin estimates that 41% of the economic inequality created between 1976-2000 was the result of changed family structure.

The authors identify three reasons why family structure is getting less attention than it should. First, some analysts do not want to give the appearance of taking the side of social conservatives.  Second, there is concern about the racial correlates of data on family structure.  Third, the problem does not lend itself to a quick fix.