PHILIPPE THALMANN is Professor of Economic at the Swiss Federal Institute of Technology in Lausanne. He teaches and writes on the economics of the housing, property and construction markets; the economics of the environment; and sustainable development. - MILAD ZARIN-NEJADAN is Professor of Economics at the University of Neuchatel in Switzerland. He is also a regular consultant to the Swiss Ministry of Economy and the OECD. His areas of expertise include economic policy, public economics and public finance. -