In late March, the Urban League issued its 2009 “State of Black America” report, which declared that “African Americans remain twice as likely as whites to be unemployed, three times more likely to live in poverty, and more than six times as likely to be incarcerated.” A week earlier, the National Center for Health Statistics (NCHS) released figures showing that in 2007, 71.6 percent of black births were to unmarried women, compared with 27.8 percent of non-Hispanic white births. The NCHS numbers came out shortly after the Census Bureau published data from its Current Population Survey (CPS). Among other things, the CPS found that in 2008, only 38 percent of black children lived with two parents, compared with 78 percent of non-Hispanic white children.

These statistics are inextricably connected. Just ask Barack Obama. “More than half of all black children live in single-parent households, a number that has doubled — doubled — since we were children,” Obama told a predominantly black congregation at Chicago’s Apostolic Church of God on Father’s Day 2008. “Children who grow up without a father are five times more likely to live in poverty and commit crime, nine times more likely to drop out of schools, and 20 times more likely to end up in prison.”

Indeed, while family breakdown is hardly the only cause of persistent racial gaps in areas such as income and education, it poses a major obstacle to reducing those gaps. More broadly, disparities in family environments are closely related to overall U.S. economic inequality, which has increased during the past few decades.

In their book The Race Between Education and Technology, Harvard economists Claudia Goldin and Lawrence Katz argue that since the early 1980s, the combination of “skill-biased technological change” (the computer revolution) and “a sharp decrease in the growth rate of the relative supply of educated workers” has greatly boosted returns to education and sent the college wage premium soaring. According to Goldin and Katz, “the wage premium for college graduates relative to high school workers” spiked from 36.7 percent to 86.6 percent between 1950 and 2005, with “most of the increase” taking place after 1980.

Meanwhile, says University of Chicago economist Derek Neal, the black-white skill gap stopped narrowing around 1990, at a time when the skill premium was skyrocketing. “There’s a pattern of consistent progress all through the Forties, Fifties, Sixties, Seventies, and Eighties,” he says. But there was no discernible progress on closing the gap between 1990 and 2000; if anything, Neal indicates, the gap may have actually widened over that period.

What explains this? Neal, director of Chicago Workshop on Black-White Inequality, says there is no clear answer. But he has written that “beginning around 1980, many factors worked together to diminish the resources available to black children. Two-parent families became even more rare in the black community, and for the first time, never-married motherhood became quite common. Further, real wages for less skilled workers fell, and the real value of transfers offered by various welfare programs declined.” Neal contends that “the magnitude of the overall relative decline in black family income since 1980 is related to changes in black family structure and the weak growth of household income among black single parents.”

Columbia social scientist Jane Waldfogel reckons that black-white skill levels began converging again in the late 1990s, citing evidence from the National Assessment of Educational Progress long-term trend tests. “When you look at the period from 1999 to 2008, you see the gap starting to close again, particularly in reading for 9- and 13-year-olds,” she says. Waldfogel notes that “there was a big decline in black child poverty in the late 1990s,” which she attributes to a booming economy, the expansion of the Earned Income Tax Credit, and welfare reform. She also credits school-accountability initiatives such as the No Child Left Behind Act with helping to trim the black-white skill gap. Neal is less optimistic. “I’m not convinced that progress has started again,” he says.

Harvard economist Roland Fryer emphasizes that blacks and whites enjoy the same rate of return on their educational investments, yet blacks aren’t investing at the same rate as whites. He points out that the black-white skill gap emerges before children enter kindergarten. After analyzing data from the Department of Education’s Early Childhood Longitudinal Study, Fryer and University of Chicago economist Steven Levitt concluded that the racial achievement gap among incoming kindergartners could be virtually eliminated by controlling for several background characteristics. However, even “observationally equivalent” black and white students diverged once they were in school.

Neal has written that the early appearance of a black-white test-score gap “is consistent with the idea that the black-white skill gap among young adults can be traced, in large measure, to black-white differences in the types of investments made in children at early ages.” And “at the dawn of the 21st century, black-white differences in family environments are by far the most important source of black-white differences in levels of resources devoted to children.”

Economist James Heckman, Neal’s University of Chicago colleague, has conducted related research on the development of cognitive and non-cognitive abilities. He believes there is a divide emerging between the children born into disadvantaged family environments and those born into better family environments. “The proper measure of disadvantage is not necessarily family poverty or parental education,” Heckman explains. “The available evidence suggests that the quality of parenting is the important scarce resource.”

This has implications for anti-inequality measures. “In designing policies to combat inequality,” Heckman writes, “it is important to recognize that about 50 percent of the variance in inequality in lifetime earnings is determined by age 18. The family plays a powerful role in shaping adult outcomes that is not fully appreciated by current American policies.”

The more we appreciate the linkage between family environments and inequality, the more we appreciate the significance of out-of-wedlock birthrates. “All measures of childbearing by unmarried women rose to historic levels in 2007,” the NCHS reports. The overall out-of-wedlock birthrate in 2007 stood at nearly 40 percent, while the rate among Hispanics passed 50 percent.

In his controversial 1965 Labor Department report calling for “a national effort” to stabilize African-American families, Daniel Patrick Moynihan noted that the black out-of-wedlock birthrate had jumped from 16.8 percent in 1940 to 23.6 percent in 1963 (over that same period, the rate among whites had increased from 2 percent to just over 3 percent). At the time, 23.6 percent seemed startlingly high — but compared with 71.6 percent (the black rate in 2007), it seems relatively low. The rate among non-Hispanic whites in 2007 was higher than the rate among blacks in 1963.

What if black family composition had not changed between 1960 and 1988? Under those conditions, according to sociologists David Eggebeen of Penn State and Daniel Lichter of Cornell, the black child poverty rate in 1988 would have been 17.2 percentage points lower. Eggebeen and Lichter detailed their findings in a 1991 American Sociological Review article. They wrote that “the changing family structure among black and white children has clearly exacerbated long-standing racial differences in child poverty. Indeed, in the absence of widening racial differences in family structure, the 1960–1988 period would have brought substantial convergence in racial differences in official, deep, and relative child poverty.”

Among others, Urban Institute economist Robert Lerman has done valuable work on the economic benefits of marriage. “The apparent gains from marriage are particularly high among black households,” he wrote in a 2002 paper. In a separate report coauthored with Israeli economist Avner Ahituv, Lerman demonstrated that, on balance, married black men earn higher wages and work longer hours than never-married black men. In a more recent study of middle-class households, Lerman estimated that between 1989 and 2004, the net worth of “middle-income married parents” increased by 52 percent while that of “middle-income unmarried parents” actually decreased by 15 percent.

President Obama is now in a unique position to shape black attitudes toward marriage and fatherhood. His 2008 Father’s Day message was clear: “We need fathers to realize that responsibility does not end at conception. We need them to realize that what makes you a man is not the ability to have a child — it’s the courage to raise one.” That is a message well worth repeating.