The effect of group purchasing on prices hospitals pay for medicines
利用法国医院2009-2014年加入区域采购团体的数据，研究发现团购略微降低药品整体价格，但对无替代药品的价格无影响，而对寡头市场药品价格影响显著。
I estimate the impact of group purchasing on medicine prices in French hospitals, taking advantage of the entry of hospitals into regional purchasing groups between 2009 and 2014. Based on a new database providing the average annual prices paid for all innovative and high-priced medicines in public hospitals, I use a two-way fixed effects model that controls for hospitals' medicine-specific bargaining power and medicine-specific price trends. I find that group purchasing slightly reduces the overall prices of medicines but has no impact on the prices of medicines that have no alternative on the market. On the contrary, prices of medicines in oligopoly markets are extensively impacted.