Economist Bernanke (3)
I believe the answer is:
ben
'economist bernanke' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ben that I've seen before include "A Scottish mountain like Nevis" , "High mountain (Scots)" , "He's big in London" , "Second part of 11" , "Mountain peak (Scot.)" .)