Following Treasury Secretary Janet Yellen’s announcement Monday about running out of time to pay bills, borrowing costs for the U.S. government soared to more than 5% for June.

This was predictable. In fact, the U.S. did default once, by accident. In 1979, a series of events including the failure of word-processing equipment caused a temporary delay in payments to investors redeeming U.S. Treasury bills, Reuters has reported.

Afterward, the cost of borrowing money for the U.S. increased by 0.6%, the wire service said, adding that an academic paper published a decade later argued that the ratcheting up of borrowing costs for the U.S was permanent.

If the U.S. were to default again, the result would be the same, said Howard Gleckman, senior fellow in the Urban-Brookings Tax Policy Center at the Urban Institute, a nonprofit research group.

NBC How Americans could be affected if the debt crisis isn’t resolved