THE QUEST is on to find a new editor of the Economist. The leading inside candidate is Bill Emmott, business editor. Nicholas Colchester, deputy editor, is also in the running, with Mike Elliott, Washington bureau chief, and Duncan Campbell-Smith, a former Financial Times Lex editor, also tipped. Matt Ridley, its former American editor, has also applied. Outsiders include Peter Jay, the BBC's economics editor, and possibly Sarah Hogg, head of John Major's policy unit and the person some credit with creating the gap in the first place, with Rupert Pennant- Rea's elevation from the editorship to deputy governor of the Bank of England. The kingmaker, Sir John Harvey-Jones, chairman of the Economist board, is following time- honoured tradition and asking staff to write in with their views. Staffer David Lipsey is running a book on the outcome: Mr Emmott's chances are put at 11:8; Mr Colchester's at 13:8. The staff's preference for Mr Pennant-Rea over Dudley Fishburn last time round is said to have swung the day.