An Empirical Study of U.S. Copyright Fair Use Opinions Updated, 1978-2019

This article presents a brief update through 2019 of the author’s previous quantitative study of all reported federal court opinions that applied the Copyright Act’s four-factor test for copyright fair use. This updated study systematically analyzes 579 copyright fair use opinions from 435 cases over the 42-year period from 1978 through 2019. The updated data show that, for better and worse, much has remained the same in our fair use case law since 2005. Most notably, the fourth factor, going to the effect of the defendant’s use on the market for the plaintiff’s work, continues ultimately to dominate the test. However, the data record a significant shift toward summary adjudication of the fair use defense, a decline in the influence of the courts of the Second Circuit, and a substantial recovery in recent years in courts’ attention to the transformativeness test for fair use.