1. Faculty of Economics, Soka University, Hachioji, Tokyo, Japan
2. Department of Quantitative Finance, National Tsing Hua University, Hsinchu, Taiwan
3. Econometric Institute, Erasmus School of Economics, Erasmus University Rotterdam, Rotterdam, The Netherlands
4. Department of Quantitative Economics, Complutense University of Madrid, Madrid, Spain
5. Institute of Advanced Sciences, Yokohama National University, Yokohama, Japan