1. Department of Operative and Preventive Dentistry, Charité–Universitätsmedizin Berlin, Berlin, Germany
2. Department of Oral Sciences, Sir John Walsh Research Institute, School of Dentistry, The University of Otago, Dunedin, New Zealand
3. Department of Oral Rehabilitation, Sir John Walsh Research Institute, School of Dentistry, The University of Otago, Dunedin, New Zealand
4. Kiel Institute for the World Economy, Kiel, Germany