Jean Chateau is senior economist (principal modeler) at the Environment Directorate of the OECD. He earned a MS in Econometric (1992) and a Ph.D. in Economics (1997) from the University Pantheon-Sorbonne, Paris. Before coming in OECD he held positions as an Economist in the CEPII, and before in the Commissariat Général du Plan. He had also been Visiting Scholar at the IMF in the research department. Jean Chateau is a macro-economic modeler, since 2000, specialist of ageing, macro-economic and environmental issues; he is actually managing the OECD “ENV-Linkages” model (CGE type of model). Since 2009 he actively collaborates each year with the IEA for its World Energy Outlook. He is also sharing the OECD representation at the GTAP board.