The Medium-Term Impact of Medicare Part D on Pharmaceutical Prices
研究了美国医疗保险D部分实施四年后对药品价格的影响，发现价格下降至少持续到第三年，对评估政策效果和药品定价机制有参考价值。
Medicare Part D began coverage of prescription drugs in 2006. Using data from the first year of the program we found that Part D reduced pharmaceutical prices for Medicare recipients, with these effects driven by enrollees previously without drug coverage. In this paper we extend our analysis through 2009, the fourth year of the program, to investigate whether plans continued to extract price concessions in return for favorable formulary placement, or if consumer inertia or other factors caused prices to bounce back after their initial decline. We find price declines persisted through at least the third year of the program.