Le Wang's research focuses on questions in the subfields of microeconomics -- labor and demographic economics, development economics and public economics -- with a particular emphasis on the development and use of distributional/nonparametric and program evaluation methods to address issues in these areas. His work has been published in journals such as Journal of Political Economy, Journal of Econometrics, Journal of Applied Econometrics, Journal of Population Economics, Journal of Environmental Economics and Management Econometrics Journal, Economic Development and Cultural Change, Health Economics, and Industrial Relations. He has received the 2018 Kuznets Prize for his article (with Chunbei Wang) “Knot yet: Minimum marriage age law, marriage delay, and earnings,” which was published in the Journal of Population Economics (2017), 30(3), pp. 771-804.