The findings add to a growing body of evidence that in most cases, a college degree helps to boost employment and earning potential -- the underemployment rate of those with just a high school diploma is 12.9%, the analysis found. But for many Americans, a college degree is out of reach without taking on debt. That’s particularly true for African-Americans. More than half of young black households hold student debt, according to a recent analysis from Demos, a left-leaning think tank, and Brandeis University’s Institute on Assets and Social Policy.