Modeling inter-regional patient mobility : does distance go far enough?

This paper estimates a theory-guided gravity equation of regional patient flows. In our model, a patient's choice to consult a physician in a particular region depends on a measure of spatial accessibility that accounts for the exact locations of both patients and physicians. Introducing this concept in a spatial economics model, we derive an augmented gravity-type equation and show that our measure of accessibility performs better in explaining patient flows than bilateral distance. We conduct a rich set of counterfactual simulations, illustrating that the effects of physicians' market exits on patient mobility crucially depend on their exact locations.