[1] New Econ Sch, Moscow 117418, Russia
[2] CEFIR, Moscow 117418, Russia
[3] CEPR, Moscow 117418, Russia
[4] WDI, Moscow 117418, Russia
[5] CNRS, ROSES, F-75647 Paris 13, France
[6] CEPR, F-75647 Paris 13, France
[7] MIT, Alfred P Sloan Sch Management, Cambridge, MA 02142 USA