The Federal Reserve’s “temporary” dollar swap lines with other major central banks are beginning to look like anything but temporary. The facilities were first introduced in December 2007, closed in February 2010, reopened in May 2010, and recently extended through August 2012. Under these agreements, the Fed offers unlimited dollar liquidity to other central banks, which in turn offer the funds to local banks that find it difficult to borrow in interbank markets.

The “re-emergence of strains in short-term US dollar funding markets” was cited by the Fed when it revived the programme last year after its brief hiatus. The recent extension of the swap lines—previously scheduled to expire next month—suggests that officials believe that these strains remain, or may be worsening. But so far the move looks like more of a precaution than a sign of imminent distress. Since announcing the extension on June 29th, no central bank has drawn on the facility (the data is reported weekly, on Thursdays). In fact, the swap lines have not been used since March, when only US$70m was drawn, a small fraction of the hundreds of billions borrowed during the depths of the crisis following the collapse of Lehman Brothers.