... Purdue and a few other universities have come up with I.S.A. programs that could point the way forward. They assess different rates and repayment durations depending on the borrower’s major. If you’re a chemical engineering major at Purdue, you enjoy better terms than if you study English: Under its I.S.A. schedule, chemical engineers are expected to repay $33,000 at the rate of about 8.5 percent of their income for seven years and four months, while for English majors it’s almost 15 percent for nine years and eight months. But these university I.S.A.s are meant to supplement rather than replace...