Gilbert Koenig BETA- University of Strasbourg   1 rue du banc strasbourg, 67100 FRANCE   koenig@unistra.fr   http://www.beta-umr7522.fr/-KOENIG-Gilbert           JEL Areas: E6 : Macroeconomic Policy, Macroeconomic Aspects of Public Finance, and General F4 : Macroeconomic Aspects of International Trade and Finance: General