I wonder if the increase in serious delinquency is being disproportionately driven by loans to for-profit institutions.

This article addresses the issue directly:

"Student debt a harsh math lesson for US graduates as wages lag" - https://www.nola.com/education/index.ssf/2018/03/student_deb...

For instance:

> Compared to their peers at other colleges, students attending for-profit institutions -- mostly those classified as inclusive, part-time or two-year -- are falling behind in their debt repayments. Twenty-two percent at for-profit schools were behind on their academic loan payments compared with six percent of students at public institutions, according to a survey by the Federal Reserve.