1. Department of Law and Economics, Chair of Applied Microeconomics, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany;
2. Department of Economics, King’s Business School, King’s College London, London WC2B4BG, United Kingdom;
3. Faculty of Economics, UniDistance Suisse, 3900 Brig, Switzerland;
4. School of Management and Law, Zurich University of Applied Sciences (ZHAW), Center for Energy and the Environment, 8400 Winterthur, Switzerland;
5. Department of Economics, George Mason University, Fairfax, Virginia 22030