[1] Erasmus Univ, Rotterdam Sch Management, NL-3000 DR Rotterdam, Netherlands
[2] Erasmus Univ, Inst Econometr, NL-3000 DR Rotterdam, Netherlands
[3] Georgetown Univ, European Univ Inst, Washington, DC 20057 USA
[4] Georgetown Univ, Dept Econ, Washington, DC 20057 USA