US policy-makers must review the oversight of retail payments systems, as the Federal Reserve lacks powers available to many other major central banks, Lael Brainard warned in a February 5 speech.

The likely entry of firms such as Facebook into the digital currency market could further weaken the Fed’s ability to regulate payments, the Fed board of governors member said.

Brainard also signalled that she was more open to the possible advantages of a central bank-issued digital currency than she