Josh Mitchell and Michelle Hackman:

But when Upjohn looked at how many students from the 2006 through 2012 high-school classes earned a bachelor’s degree within six years of their graduation, it found the rate for white students, 46%, was triple the rate for black students.

And among high-school graduates from mid/high-income households—defined as those not eligible for free or reduced-cost school lunches—the percentage of students earning some kind of college credential jumped to 56% from 43%, a contrast to the nearly unchanged figure for black students. The institute’s Mr. Hershbein said this is where the other layers of the onion—the societal problems preventing students from being prepared for college—are revealed.

About 55% of children in Kalamazoo come from single-parent households, U.S. Education Department figures show. In recent years, as many as 7% of the city’s public-school students were homeless, twice the national average, also based on Education Department data. The teen pregnancy rate in Kalamazoo County is nearly 50% higher than the national rate, according to state and federal data.

Mr. Hershbein said such problems undermine students’ ability to persist in college even with tuition costs covered. Some drop out to take care of family members. Others weren’t academically prepared for college and are overwhelmed when they get there, he said.

Mr. Hershbein said his research tells a more encouraging story. College graduation rates among minorities have indeed been flat in Kalamazoo. But they fell in other Michigan cities with similar demographics in the most recent recession and early in the expansion, he said.