1. Group of Researchers for Applications of Physics in Economy and Sociology, GRAPES, B5a Sart-Tilman, B-4000 Liège, Belgium
2. The Virtual Knowledge Studio for the Humanities and Social, Sciences at the Royal Netherlands Academy of Arts and Sciences, VKS-KNAW, Cruqiusweg 31, 1019 AT Amsterdam, The Netherlands
3. Faculty of Earth and Life Sciences (FALW), De Boelelaan 1085, 1081HV Amsterdam, The Netherlands