Case in point: A former student with debt of $10,000 is more likely to default on her loans than a student owing $100,000, according to federal data. That’s because the lower debt total signals the student probably dropped out before completing school. And evidence suggests that taking some college courses without ever earning a degree gives workers a paltry wage boost compared to those who actually graduate. The obverse is also telling: Students with heavy debt loads are more likely to have earned graduate degrees that often lead to much higher incomes.

The type of school a student attends also can predict her ability to pay down her debt. New federal data about how often students repay their loans show those who attended for-profit colleges, such as the 35,000 students at the recently shuttered ITT technical colleges, have a three-year repayment rate of 46 percent—meaning less than half are able to pay down their debt by at least a dollar. That’s the lowest among all the types of schools The Institute for College Access and Success analyzed, well below four-year public schools (81 percent); community colleges (57 percent); and private, nonprofit schools (78 percent) such as Duke and the University of Southern California.

The story of loan defaults is about for-profit colleges, too. The most recent available data show 8 million borrowers have defaulted on $128 billion in federally issued loans. Though in recent years the rate of defaulters has declined, these people—who haven’t made a payment on their debt in 270 days—are ineligible for the federal government’s repayment plans. These plans cap what one owes each month to a percentage of what she or he earns, and defaulters cannot utilize them unless they rehabilitate their loan status. Even though roughly a tenth of college students in the U.S. are in for-profit schools, they account for nearly 40 percent of all college-related defaults.

Some students who were enrolled at for-profit colleges that have shut down are eligible for debt forgiveness, but they must make a choice between having their loans expunged or keeping the credits they earned from these schools in hopes of transferring them to a new college. This transfer process is easier said than done, though, as multiple reports indicate community colleges are rejecting most of those credits anyway. In a press call with reporters last week, Under Secretary of Education Ted Mitchell said students who were enrolled at ITT on May 6 or later are eligible for debt relief under the education department’s closed-school provision.

But those students can’t recover the Pell grants—federal aid reserved for low-income students—they used to attend the closed colleges. And education benefits used by veterans are also presently irretrievable.

Roughly 7,400 students affected by last year’s collapse of Corinthian Colleges had their debts pardoned via the closed-school rule. Another nearly 3,800 received debt jubilees through a relief program available to students who can show they were defrauded by their schools. As more state attorneys general build cases against the alleged deceptive tactics Corinthian Colleges and ITT used to recruit students, potentially hundreds of thousands of former students could see their debts pardoned—with taxpayers effectively eating the costs. The ITT fallout alone could cost the U.S. Treasury approximately $500 million of revenue if every student who’s eligible for closed-school debt relief applies for it. Should more for-profit colleges fall, which some analysts predict, these sums could mushroom.