More are falling behind on student loans

More student debtors are dropping behind on their federal student loans, after three years of declines in late payments - and with no clear explanation, experts aren't sure whether to take it as a sign of distress or a temporary blip.

The share of Americans at least 31 days late on loans from the U.S. Department of Education ticked up to 18.8 percent as of June 30, up from 18.6 percent the same time last year, new federal data show.

About 3.3 million Americans have gone more than a month without making a required payment on their Education Department loans - up about 320,000 borrowers.

The rise interrupts a period of 12 straight quarters of declines in delinquency rates, according to numbers dating to 2013, and comes despite the fact that the economy has improved, which normally would mean richer borrowers better able to afford their bills.

The uptick may be small compared to the 17 million debtors repaying their loans, but it surprised economists and government officials, who struggled to explain the reasons behind it.

'There's no fundamental reason for that to be happening,” said Yelena Shulyatyeva, senior U.S. economist for Bloomberg Intelligence. After all, she said, the economy has improved since June of last year, with lower unemployment, higher household incomes and increased wealth, federal data show.

Consumers are more confident about the economy and their own personal finances, too, according to Bloomberg Consumer Comfort data.

'The fact that the trend has stalled is not yet a warning sign, but it is a question mark,” said James Kvaal, who was deputy director of the White House Domestic Policy Council under President Barack Obama.

Kvaal attributed the last few years' fall in delinquency rates from a high of 27.1 percent in 2013 to the stronger economy and to the Obama administration's policies, including its expansion of generous government plans that let debtors make monthly payments based on their income, not on what they owe.