Anthony Hennen of the Martin Center devotes a column to the issue of parents taking on debt for their children’s higher education.

Student loan debt remains a burden for millions of college graduates and dropouts, but the federal government has not yet hit the brakes on its loan engine. Now, it’s becoming a greater problem for parents.

A recent analysis by Mark Kantrowitz, a higher education expert who publishes Saving for College and Private Student Loans, noted that student debt held by students is flattening, but student debt held by parents has increased almost 20 percent since 2012. A combination of more students hitting loan limits, and rising college costs, has shifted the burden to parents through the PLUS loan program, which has no borrowing limits.

Given the details of PLUS loans, abolishing them entirely might be a better policy objective than keeping them or trying to reform them.

PLUS loans are open to graduate and professional students, as well as parents of undergraduate students. Students and parents can borrow up to the cost of attendance set by the student’s university, minus other aid the student receives. What that means is the federal government imposes no direct borrowing limit. If a school sets tuition higher and higher every year, a PLUS loan will cover the increase.

And the participation rate for parents is rising rapidly. Almost one in every five undergraduate students had a parental PLUS loan attached to them in 2012, according to the National Center for Education Statistics.