“…Ideally, we could draw on patient‐level data and model the individual patients' choices of their physicians, similar to Kessler and McClellan (
2000) and Gowrisankaran et al. (
2018) in modeling patients' hospital choices, and derive the parameter β from these estimates. Lacking these data, we estimate Equation () with the spatial accessibility measures
and
, respectively, as well as regional fixed effects
and
as regressors.…”