1. Center for Mathematics and Computer Science (CWI), Amsterdam 1098 XG, The Netherlands
2. Department of Economics, Middlesex University Business School, Hendon Campus, The Burroughs, London NW4 4BT, UK
3. EMLYON Business School, University of Lyon, GATE L-SE UMR 5824, 69131 Ecully, France
4. Business School, University of Nottingham, Jubilee Campus, Nottingham NG8 1BB, UK