“…We also link individual physicians' behavior to administrative data about their practice characteristics to address potential heterogeneity in individuals' health service provision and the quality of care in the experiment. We thus explore how experimental behavior relates to physicians' real-world characteristics and contribute to the generalizability of experimental results (Levitt andList, 2007, 2009; Czibor et al, 2019). The practice characteristics we consider comprise annual practice profit, location (city, outer conurbation, rural area), patient-related characteristics (share of patients in the statutory health insurance (SHI) scheme, revenue share, and time spent on SHI patients), 6 and whether more than one physician is employed in the practice.…”