Effects of Copyrights on Science. Evidence from the WWII Book Republication Program

Copyrights, which establish intellectual property in music, science, and other creative goods, are intended to encourage creativity. Yet, copyrights also raise the cost of accessing existing work - potentially discouraging future innovation. This paper uses an exogenous shift towards weak copyrights (and low access costs) during WWII to examine the potentially adverse effects of copyrights on science. Using two alternative identification strategies, we show that weaker copyrights encouraged the creation of follow-on science, measured by citations. This change is driven by a reduction in access costs, allowing scientists at less affluent institutions to use existing knowledge in new follow-on research.