"There isn't a prominent alternative, so especially politically this was the expedient thing to do," he said.
By his own admission Mr Bernanke was slow to recognise the severity of the mortgage meltdown at the heart of the recession.
But Mr Banerji is not surprised that many economists have welcomed his reappointment.
"The reason they have been so laudatory is that Bernanke's performance over the past year has simply dazzled economists," he said.
"But if you look at his record before that, and his culpability for creating the situation in the first place, it's much more of a mixed bag...."