Professionals and students in a lobbying experiment. Professional rules of conduct and subject surrogacy

Lobbying is studied in a series of signaling game experiments. Students as well as professional lobbyists are used as subjects. In contrast with some earlier studies, comparing students and professionals, we find significant differences in the behavior of the two subject pools. Professional subjects appear to behave more in line with the game-theoretic predictions, display a higher degree of separation, and earn more money. We show that professional rules of conduct and professionalization can explain these differences. Although our results suggest that subject surrogacy is a relevant issue in this field of research, arguments are provided why experimentation with student subjects remains useful to study lobbying.