He is also an Adjunct Research Fellow at Korea Development Institute (KDI). He has a Ph.D. in economics from University of British Columbia, and a M.A. in economics and a B.A. in business administration both from Beijing University. His research interests center on institutions, development and subjective well-being. His has been published in journals such as Social Indicators Research and Journal of Happiness Studies. He also co-authored chapters on the ranking and dynamics of world happiness in the World Happiness Report 2012 and 2013.