In 2007, following the Supreme Court’s first opinion addressing obviousness in the Federal Circuit era ofpatent law, Rebecca Eisenberg and Harold Wegner, two of the most prominent voices in patent law, offered competing predictions about the effect KSR International Co. v. Teleflex, Inc. would have on the Federal Circuit’s obviousness jurisprudence. Seeing KSR as part of a broader admonishment against the use of rigid rules rather than providing any substantive guidance, Eisenberg foresaw a future in which KSR changed what the Federal Circuit said about obviousness but not what it did. Wegner, in contrast, predicted that KSR would change case outcomes: inventions that were nonobvious the day before KSR would suddenly become obvious after the Court’s opinion.

This study empirically examines these two predictions using a novel dataset comprised of all pre- and post-KSR Federal Circuit decisions on obviousness over a fifteen-year period. This data reveals strong evidence that KSR has indeed altered the outcomes of the Federal Circuit’s obviousness determinations, a change that has manifested in large part through an increase in the deference that the Federal Circuit is giving to district court determinations that patents are obvious as opposed to a shift in the substance of the law itself.

Moving beyond an examination of outcomes alone, this study uses the technique of content analysis to explore the heart of the second prediction: that KSR would affect what the Federal Circuit says about obviousness. This analysis demonstrates that the Federal Circuit has indeed changed what it says. Essentially gone is the use of the Federal Circuit’s ubiquitous pre-KSR “teaching, suggestion, or motivation” (“TSAI”) framework in analyzing obviousness. Furthermore, while the underlying requirement that patent challengers identify some “reason to combine” or “reason to modify” prior art references has endured, it is hardly a reincarnation of TSAI, either in terms of vigor or structure. Instead, the Federal Circuit’s new obviousness framework allows substantial flexibilily in the obviousness analysis.