DURING the financial crisis of 2008, LIBOR was a gauge of fear. The London inter-bank offered rate—at which banks are willing to lend to one another—leapt. (Even then it may have been too reassuring: banks have since been fined billions, and traders jailed, for rigging it.) Lately it has been climbing again: on August 22nd three-month dollar LIBOR rose above 0.82%. That is no cause for panic, but it is a seven-year high and 0.2 percentage points more than in June. What’s going on?

Increases in LIBOR, a benchmark used to set rates for trillions of dollars’ worth of loans, usually reflect either strains on banks or expected rises in central banks’ policy rates. Although the Federal Reserve has been toying with tightening, this time LIBOR’s ascent has another explanation, traceable to the turmoil of 2008. A change by the Securities and Exchange Commission (SEC) in the regulation of American money-market funds has made borrowing pricier, especially for foreign banks.

Before the crisis investors in money-market funds—which lend for short periods to banks, other companies and the government—had become accustomed to...Continue reading