Does Intellectual Property Restrict Output? An Analysis of Pharmaceutical Markets
研究了药品专利到期后产出不升反降的现象，发现专利通过激励营销（非价格竞争）抵消部分垄断成本，短期专利到期减少产出和消费者福利，长期福利改善幅度比仅考虑价格下降时低30%。
Standard analysis of intellectual property focuses on the balance between incentives for research and the welfare costs of restraining output through monopoly pricing. We present evidence from the pharmaceutical industry that output often fails to rise after patent expirations. Patents restrict output by allowing monopoly pricing but may also boost output and welfare by improving incentives for marketing, a form of nonprice competition. We analyze how nonprice factors such as marketing mitigate and even offset the costs of monopoly associated with intellectual property. Empirical analysis of pharmaceutical patents suggests that, in the short run, patent expirations reduce output and consumer welfare by decreasing marketing. In the long run, patent expirations benefit consumers, but by 30 percent less than would be implied by the reduction in price alone. Focusing only on the pricing issues of intellectual property may lead to incomplete or even inaccurate conclusions for welfare.