STUDENT loans are based on a simple idea: that a graduate's future flow of earnings will more than cover the costs of doing a degree. But with unemployment rates in parts of the rich world at post-war highs, that may no longer hold true for many people. The consequences will be felt by everybody. All over the world student indebtedness is causing problems—witness this month's violent protests in Chile (see article). In Britain, according to a recent parliamentary report, rising university fees mean that student debt is likely to treble to £70 billion by 2015. But, partly because higher education there is so expensive, the scale of the problem is far greater in America. When the next official estimates of outstanding student debt there are published, it is expected to be close to $1 trillion, higher than credit-card borrowing (see article). Credit quality in other classes of consumer debt has been improving; delinquency rates on student loans are rising. Many of the anti-Wall Street protesters push the idea of blanket debt forgiveness as a solution. But that is the wrong answer. Higher education is not a guarantee of employment, but it improves the odds immensely. Unemployment rates among university graduates stood at 4.4% on average across OECD countries in 2009. People who did not complete secondary school faced unemployment rates of 11.5%. Much of the debt that students are taking on is provided or guaranteed by the government. Imposing write-offs on all taxpayers to benefit those with the best job prospects is unfair; and ripping up contracts between borrowers and private lenders is usually a bad idea. That said, student-loan systems in America and elsewhere are often badly designed for an extended period of high unemployment. In contrast to the housing crash, the risk from student debt is not of a sudden explosion in losses but of gradual financial suffocation. The pressure needs to be eased.

One option is to change the bankruptcy laws. In America, Britain and elsewhere, these treat student debt as a special case: unlike other forms of debt, it cannot be wiped out. If student debt is not to shackle existing graduates and put off future ones, the rules could be changed so that it is dischargeable in bankruptcy. Yet the reasoning behind the current bankruptcy provisions is logical enough: education is an asset that cannot be repossessed and that keeps on benefiting the individual through his or her lifetime. Some worry that graduates would rush to declare bankruptcy, handing losses to taxpayers.

So a second option is preferable. Many countries, America included, have designed student debt primarily as a mortgage-like obligation: it is repaid to a fixed schedule. Other places, like Britain and Australia, make student-loan repayments contingent on reaching an income threshold so that the prospect of taking on debt is more palatable to people from poorer backgrounds. That approach makes sense, especially when jobs are scarce. Barack Obama this week proposed to limit loan payments for some struggling American graduates to 10% of discretionary income and forgive outstanding debt after 20 years. Income-based repayment ought to become the norm.

Degrees of clarity

Both changes would lead to a repricing of student debt. That would be a bad thing for taxpayers, but a good thing overall. Just as borrowers need to understand the risks they are exposing themselves to, voters need to understand the liabilities that governments are taking on when they subsidise students. If such information were made public, other useful data would follow—on the average financial returns to graduates of specific subjects, for example. Those studying less lucrative subjects would have to pay more, or be subsidised more. It would be a controversial approach, but a more educated one.