Scale, Scope, and Spillovers: The Determinants of Research Productivity in Drug Discovery
利用企业内部数据，发现大型药企的研发更高效，不仅因规模经济，更因项目组合多样化带来的范围经济和知识溢出，这解释了为何容忍大企业市场势力以换取创新优势。
We examine the relationship between firm size and research productivity in the pharmaceutical industry. Using detailed internal firm data, we find that larger research efforts are more productive, not only because they enjoy economies of scale, but also because they realize economies of scope by sustaining diverse portfolios of research projects that capture internal and external knowledge spillovers. In pharmaceuticals, economies of scope in research are important in shaping the boundaries of the firm, and it may be worth tolerating the static efficiency loss attributable to the market power of large firms in exchange for their superior innovative performance.