Judd is an experimental economist who conducts research in the fields of market design, public economics, and labor economics. 

Judd’s market design research places particular emphasis on bringing innovations from theory to practice. Applications include course allocation and priority systems for life-saving donor organs. Judd also investigates the forces that motivate people to contribute to public goods. Applications include worker effort, job choice, organ donation, and charitable giving. Judd is a world expert on summer youth employment programs, their impact on youth outcomes, and how they can be improved. He also conducts research on gender differences that might impact labor market outcomes and on discrimination in labor markets.

Judd is an NBER Research Associate and a J–PAL Affiliate. His research has appeared in general interest journals including the American Economic Review, The Quarterly Journal of Economics, Econometrica, the Proceedings of the National Academy of Sciences, and Management Science. In 2021, Judd was awarded the Vernon L. Smith Ascending Scholar Prize.