- 2020/04 - 現在 Distinguished Professor, Keio University Senior Institute Member
- 1998/06 - 現在 大学教授(経済学部)
- 1998/06 - 現在 大学院経済学研究科委員
- 1998/06 - 2020/03 Member, Graduate School of Economics, Keio University
- 1998/06 - 2020/03 Professor, Department of Economics, Keio University
- 2001/09 - 2001/12 Visiting Professor, California Institute of Technolocy
- 1999/10 - 2001/09 大学国際センター学習指導主任
- 1992/04 - 2000/03 Visiting Research Fellow, International Research Center for Japanese Studies
- 1993/04 - 1998/05 Associate Professor, College of Economics, Nihon University
- 1989/04 - 1993/03 Associate Professor, Population Research Institute, Nihon University
- 1987/04 - 1989/03 Research Fellow, Population Research Institute, Nihon University
- 1985/12 - 1987/02 Research Fellow, Population Institute, East-West Center
- 1985/12 - 1987/02 米国東西センター人口研究所 ,リサーチ・フェロウ
- 1982/09 - 1985/11 Research Assistant, Population Research Center, University of Chicago
- 1982/09 - 1985/11 シカゴ大学人口研究センター ,リサーチ・アシスタント