1. Department of Economics; Ruhr University of Bochum; D-44801 Bochum Germany
2. Kiel Institute for the World Economy; D-24105 Kiel Germany
3. Department of Economics and Business Administration; Chemnitz University of Technology; D-09126 Chemnitz Germany
4. FOM Hochschule für Oekonomie and Management; University of Applied Sciences; D-45127 Essen Germany