Following Dominique Strauss-Kahn’s resignation, the International Monetary Fund needs a new head. There is much talk of the candidate’s nationality but much less about another vital issue: that the fund’s next leader should not be an active politician.

The case for a politician, especially a European politician, at first seems strong. Many of the fund’s largest programmes are in Europe. The new head must enjoy the confidence of European leaders if they are to have hope of forging consensus among them. He or she also needs to understand the nuances of European politics, to avoid pressing for genuinely infeasible actions.

The most able candidates may even want the job as a path to political redemption, or a stepping stone towards higher office. Yet these are precisely the reasons why someone whose primary skill is political would be an unwise choice. The fund is designed to push tough policies to straighten out countries that have mismanaged finances, not win a popularity contest.