Patent Law & Policy

The patent system operates within a dynamic legal and institutional context. Over the past half century, landmark legislation, Supreme Court decisions, and policy changes have fundamentally reshaped the rules governing patents — who may obtain them, what subject matter is patent-eligible, and how patents may be enforced. These legal shifts have had substantial effects on patenting behavior, with observable impacts on the trends documented throughout this book.

The timeline below chronicles the most consequential changes to United States patent law and policy from 1980 to the present. Each event entry includes a description of its impact and references to published academic research examining its effects.

Several of the legal events documented above exhibit observable effects on the patent data examined in earlier chapters:

• Bayh-Dole Act (1980): Coincided with a substantial increase in university patenting, though scholars debate whether the Act catalyzed the trend or formalized an existing one. Government-funded patents (Public Investment) began rising in the 1980s as universities established technology transfer offices.
• Court of Appeals for the Federal Circuit (1982): Unified and strengthened patent rights, a change widely cited as a factor in the upward trend in patent grants through the 1990s and 2000s (Patent Count).
• State Street Bank v. Signature Financial Group (1998): Established the patentability of business methods. The subsequent acceleration in software patent filings is consistent with this ruling, observable as the acceleration of Section G (Physics) and H (Electricity) patents in the late 1990s (Patent Fields).
• America Invents Act (2011): Created the PTAB inter partes review system, providing a faster and cheaper alternative to litigation for challenging patent validity. The shift to first-inventor-to-file changed priority rules for all patents filed after March 2013.
• Alice Corp. v. CLS Bank International (2014): The Court held that abstract ideas implemented on generic computers are not patent-eligible under 35 U.S.C. § 101, substantially narrowing patent eligibility. This holding may have contributed to a moderation in software-related patenting in subsequent years, though Sections G and H continued to grow in absolute terms.

The efficiency of the patent system in processing inventions warrants examination. Comparing the number of patent applications filed each year against the grants issued allows tracking of the USPTO's throughput and the growing gap between filing and granting activity. The ratio of grants to applications indicates how the system's selectivity and backlog have evolved over time.

The Alice Corp. decision (2014) restricted patent eligibility for abstract ideas implemented on generic computers. Despite widespread concern that the ruling would curtail software patenting, an aggregate comparison of software patents against a control group shows continued growth in both patent counts and claim complexity. To assess the impact more precisely, this section then examines Alice-affected USPTO art groups (treatment) against unaffected art groups (control), with values indexed to 2013 = 100.

A terminal disclaimerA legal mechanism in which a patent owner voluntarily shortens a patent's term to match a related earlier patent, typically to overcome an obviousness-type double patenting rejection. Terminal disclaimers tie the enforceability of the later patent to the earlier one. is a mechanism by which a patent owner voluntarily limits the patent's enforceable life to match that of a related patent, typically filed to overcome a double-patenting rejection. The rate of terminal disclaimer usage provides insight into patent portfolio strategy: higher rates suggest more intensive efforts to obtain overlapping patent claims on related inventions.

When the USPTO delays in examining a patent application beyond statutory deadlines, the patent term is extended through Patent Term Adjustment (PTA). The median PTA provides a measure of examination delay beyond what the statute envisions as timely processing. Tracking PTA over time reveals the USPTO's evolving capacity to meet statutory examination timelines.

Having examined the legal and policy framework that governs the patent system, the analysis turns to the role of public investment in shaping innovation. The following chapter investigates how government funding and public research expenditures have shaped patenting activity, and what the evolving relationship between federal investment and patent output reveals about the foundations of the innovation ecosystem.