Affiliation: | The author is an economist at the Centre d'Etudes Prospectives d'Economie Mathématique Appliquées à la Planification, Paris, and at the Centre for Economic Policy Research, London. He thanks Violeta Rosenthal for her invaluable assistance, and Nicholas Hope, Homi Kharas, Violeta Rosenthal, and John Underwood for their comments on previous versions of this article. |