Do Patents Weaken the Localization of Innovations? Evidence from World's Fairs
利用19世纪化学行业专利制度的外生变化，研究专利是否促进了创新的地理扩散。基于1851-1915年四届世界博览会上的美国创新数据，发现专利率上升后创新活动本地化程度降低。
This article takes advantage of an exogenous shift towards patenting in chemicals to test whether patents contribute to the geographic diffusion of innovations. Data on U.S. innovations that were exhibited at four world fairs between 1851 and 1915 suggest that innovative activity became less localized after patenting rates increased. These changes cannot be explained by changes in the localization of chemical production or economy-wide changes in the localization of innovations.