This grant funds a suite of three research projects by Heidi Williams of MIT to estimate the returns on R&D investments. All three projects deal with how private and public interests diverge and to what extent that divergence is mitigated or created by the patent system. The first study asks how much “stealing” from previous innovations may increase private returns without necessarily increasing social returns. Working with Daron Acemoglu (MIT), Williams will measure “citations stolen” from patents that served as “prior art” for a given innovation. Because advances do not always come about due to new knowledge per se, but rather due to marginal or technical improvements on existing technologies, “follow-on innovations” can earn more private returns than warranted by the new social value they create. Williams will compare citation data between successful and unsuccessful patent applications to help quantify the extent to which progress depends on substituting new ideas for old ones, rather than the generation of completely new or disruptive capabilities. For the second study, Williams and co-authors Pat Kline (University of California, Berkeley), Nevianna Petkova (U.S. Office of Tax Analysis), and Owen Zidar (University of Chicago Booth School of Business) will merge data on U.S. patent applications with IRS tax records to investigate which firms and which workers profit from a patent. By carrying out event studies, the team will specifically trace how spillovers accrue to private parties other than the original inventors. The third study, with Eric Budish (Chicago Booth) and Ben Roin (MIT Sloan School of Management), seeks evidence to support the common but unproven assumption that patents increase innovation. What happens, for example, when the patent for a basic ingredient expires, but a “new use” is found during the unprotected period? Preliminary findings indicate a drop-off in for-profit (but not publicly funded) research on a drug once a generic competitor can enter the market. Williams and her collaborators will estimate the social value of “missing” research investments that private interests are not undertaking now, but would if incentive systems were different.