1. Fondazione Eni Enrico Mattei (FEEM) and Centro Euromediterraneo sui Cambiamenti Climatici (CMCC), 20123 Milan, Italy
2. Department of Management, Economics and Industrial Organization, Politecnico di Milano, 20156 Milan, Italy; and Fondazione Eni Enrico Mattei (FEEM) and Centro Euromediterraneo sui Cambiamenti Climatici (CMCC), 20123 Milan, Italy