1. CAMS (CNRS/EHESS) 190, avenue de France, 75013 Paris, France
2. Institut des Systèmes Complexes Paris-Ile de France (ISC-PIF), 57-59 rue Lhomond, 75005 Paris, France
3. Department of Management Science and Innovation, University College London (UCL), Gower Street, London WC1E 6BT, UK
4. Centre for Advanced Spatial Analysis (CASA), University College London, 90 Tottenham Court Road, London W1N 6TR, UK
5. Institut de Physique Théorique, CEA, IPhT, CNRS-URA 2306, 91191 Gif-sur-Yvette, France