Entry and regulation: evidence from health care professions
研究药店地理进入限制对药店和医生数量的影响，发现限制使药店减少超50%，间接使医生减少约7%，且取消限制并降低监管加价可让利消费者而不减少药店数量。
In many countries, pharmacies receive high regulated markups and are protected from competition through geographic entry restrictions. We develop an empirical entry model for pharmacies and physicians with two features: entry restrictions and strategic complementarities. We find that the entry restrictions have directly reduced the number of pharmacies by more than 50%, and also indirectly reduced the number of physicians by about 7%. A removal of the entry restrictions, combined with a reduction in the regulated markups, would generate a large shift in rents to consumers, without reducing the availability of pharmacies. The public interest motivation for the current regime therefore has no empirical support.