Research visit at Stanford in Washington (Washington DC, United States), on invitation from David D. Laitin in January 2011 (3 weeks).

Research visit at IZA – Institute of Labor Economics (Bonn, Germany), on invitation from Klaus F. Zimmermann in August 2010 (2 weeks).

Research visit at the Department of Political Science at Stanford University (Palo Alto, United States), on invitation from David D. Laitin in January 2010 (3 weeks).

Research visit at the Department of Politics at New York University (New York, United States), on invitation from Léonard Wantchekon from February to April 2008 (3 months).