Raymond Barre, Giscard said in naming him prime minister, was "le meilleur économiste en France." It didn't endear him to the French. Neither did Giscard's own claimed competence in economics. On the other hand, Pierre Mendès France was also an economist of sorts, and his rigor in this realm earned him more than a little respect. By "economist" in this context I don't mean Paul Samuelson or John Maynard Keynes, just somebody who recognizes certain constraints on what is and is not feasible. There are times when voters appreciate the restraint that economic sobriety imposes, and other times when they don't. But it's not simply a matter of conjuncture whether they like to hear what the numerate economist has to say. He also has to convince them that the numbers are not merely decoys laid out to distract attention from distributional decisions made sotto voce.
This will be Dominique Strauss-Kahn's challenge, since he will be running, if he runs, in part on his credentials as an economist. He has to make sure that this word means something other than "scold" or, worse, "tool of capital." On key economic issues, such as the necessity of retirement reform, his analysis is not very different from Sarkozy's. Hence he must take extra pains to prove that this analysis is only part of a broader vision of France's economic future that does differ in significant respects from his opponent's. This is a larger challenge than he has yet to acknowledge. It will be interesting to see how he meets it.