America has gone through a rapid social experiment over the last 20 years. We have created a system, in large part through public disinvestment, where our young people take on large amounts of student debt in order to achieve a college degree. The sea change has been so quick it’s been difficult to gather even basic, solid numbers on it, making the consequences of such massive student debt subject to intense debate.

A new report from Beth Akers and Matthew M. Chingos of the Brookings Institution has further fueled that debate, arguing that the conventional story of escalating debt burdens due to student loans are overstated. Even though the number of young households with debt has increased from 14 percent to 36 percent between 1989 and 2010, the percentage of monthly income those people put toward their student debt payments is largely the same. Even though student loan debts are going up, they've been accompanied by rising incomes, largely balancing out the burden. The focus shouldn’t be on student loans broadly, and instead on more targeted solutions like focusing on those who drop out of college but still have debt.

But this study, like many arguments along these lines, suffers from a major problem: It focuses on a month-to-month comparison. When we look at the effects of a major economic change—whether it’s government debt, taxes, or replacing a system of publicly funded free colleges with a system of debt for a diploma—we can’t just look at what immediately happens. We need to also consider how people behave in the long run. And when we look at student loans from the point of view of a lifetime, the results are more worrisome.

How could this matter? An infamous study on student debt by Jesse Rothstein of the University of California, Berkeley, and Cecilia Elena Rouse of Princeton looked at the results of a highly selective university replacing loans with grants. It concluded “that debt causes graduates to choose substantially higher-salary jobs and reduces the probability that students choose low-paid ‘public interest’ jobs.”

Let’s imagine two scenarios. In the first you have high student loans, so you work for a corporation in the private sector for high wages. And in the second you have virtually no student loans, and you work for less wages in a job focused on the public interest, say as an educator or at a nonprofit. In both cases your student loan payment would be the same as a percentage of your income. The Brookings result would hold. However your lifetime choices will have radically changed as a result.