Business visits, knowledge diffusion and productivity / Mariacristina Piva (Universitá Cattolica del Sacro Cuore), Massimiliano Tani (UNSW Canberra and IZA), Marco Vivarelli (Universitá Cattolica del Sacro Cuore, UNU-MERIT and IZA) ; IZA, Institute of Labor Economics. Bonn, Germany : IZA Institute of Labor Economics, December 2016