1. Ladislaus von Bortkiewicz Chair of Statistics, C. A. S. E.-Center for Applied Statistics and Economics; Humboldt-Universität zu Berlin; Unter den Linden 6 10099 Berlin Germany
2. Lee Kong Chian School of Business; Singapore Management University; Singapore
3. Max Planck Institute for the History of Science; Boltzmannstraße 22 14195 Berlin Germany