(2010-05-28) Fredriksson, Sami; Hyvärinen, Olli; Mattila, Mikko; Wass, Hanna; University of Helsinki. Department of Economics and Political Studies - Fredriksson, Sami; University of Helsinki. Department of Economics and Political Studies - Hyvärinen, Olli; University of Helsinki. Department of Economics and Political Studies - Mattila, Mikko; University of Helsinki. Department of Economics and Political Studies - Wass, Hanna