| 来源类型 | Working Paper |
| 规范类型 | 报告 |
| DOI | 10.3386/w23640 |
| 来源ID | Working Paper 23640 |
| The Landscape of US Generic Prescription Drug Markets, 2004-2016 | |
| Ernst R. Berndt; Rena M. Conti; Stephen J. Murphy | |
| 发表日期 | 2017-07-31 |
| 出版年 | 2017 |
| 语种 | 英语 |
| 摘要 | Since the 1984 passage of the Waxman-Hatch Act, generic prescription drugs have become central to disease treatment and generic drug entry and price competition has been vigorous in the U.S. Nonetheless, recent policy concern has focused on potential supply inadequacy and price increases among selected generic drugs. Details regarding the supply of generic drugs throughout the product life cycle are surprisingly unstudied. Here, we examine manufacturer entry, exit, the extent of competition and the relationship between supply structure and inflation adjusted prices among generic drugs. Our empirical approach is descriptive and reduced form, following recent innovations on the older structure-conduct-performance tradition. We employ quarterly national data on quantities, wholesale dollar sales and manufacturers from QuintilesIMS National Sales Perspective data, 2004Q4–2016Q3. Defining a market as the molecule-dosage-form, we observe that median sizes of drug markets are predominantly small, with annual inflation adjusted sales revenues of less than $10 million but increasing over time. The median number of manufacturers in each market is about two, the mean about four. We find evidence to suggest decreasing numbers of suppliers over our study period, particularly following implementation of the Affordable Care Act in 2010 and the Generic Drug User Fee Amendments of 2012, attributable both to more exit and less entry. Approximately 40 percent of markets are supplied by one manufacturer; the share of markets supplied by one or two manufacturers is observed to increase over time and is more likely among non-oral drugs and those belonging to selected therapeutic classes. We find evidence to suggest prices of generic drugs are statistically significantly increasing over time, particularly following the implementation of the 2010 Affordable Care Act and the 2012 Generic Drug User Fee Amendments. Price increases are positively correlated with reduced manufacturer counts and alternative measures of increased supplier concentration, holding all else constant. Our results suggest the market for generic drugs is largely comprised of small revenue products the supply of which has tended towards duopoly or monopoly in recent years. Therefore, it is surprising generic drug prices have not been observed to be higher and potentially risen more over our study period. This issue merits further study; we suggest several testable hypotheses based in economic theory. |
| 主题 | Health, Education, and Welfare ; Health |
| URL | https://www.nber.org/papers/w23640 |
| 来源智库 | National Bureau of Economic Research (United States) |
| 引用统计 | |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/581314 |
| 推荐引用方式 GB/T 7714 | Ernst R. Berndt,Rena M. Conti,Stephen J. Murphy. The Landscape of US Generic Prescription Drug Markets, 2004-2016. 2017. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 资源类型 | 版本类型 | 开放类型 | 使用许可 | ||
| w23640.pdf（697KB） | 智库出版物 | 限制开放 | CC BY-NC-SA | 浏览 | ||
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