Patent law reform and innovation: An empirical assessment of the last 20 years

We ask whether four of the most important U.S. patent system reforms of the last 20 years—elimination of presumptive injunctive relief for victorious patent enforcers in eBay Inc. v. MercExchange, LLC, 547 U.S. 388 (2006); creation of the Patent Trial and Appeal Board (PTAB) in the America Invents Act; restriction of software’s eligibility for patent protection in Alice Corp. v. CLS Bank Int’l, 573 U.S. 208 (2014); and limitation of patent enforcers’ choice of forum in TC Heartland, LLC v. Kraft Foods Grp. Brands, LLC, 137 S. Ct. 1514 (2017)—had a measurable impact on innovation in the U.S. Specifically, we use a sample of publicly traded firms to construct firm-level measures of innovation and exposure to each reform and adopt a variety of difference-in-differences approaches that assesses how innovation-related activities changed post-reform at relatively exposed versus relatively unexposed firms. We find: a positive association between eBay and R&D spending by firms that were relatively more exposed to patent litigation prior to the Court’s decision; a positive association between the introduction of PTAB proceedings and R&D expenditures by firms that innovate in tech classes where PTAB has been most active; a positive association between Alice and R&D spending by software firms; and a positive association between TC Heartland and R&D spending by firms that thereafter could not be sued in the Eastern District of Texas, a court long associated with opportunistic forum shopping.