New paper in The RAND Journal of Economics

Abstract:

Many studies rely on patent citations to measure intellectual heritage and impact. In this article, we show that the nature of patent citations has changed dramatically in recent years. Today, a small minority of patent applications are generating a large majority of patent citations, and the mean technological similarity between citing and cited patents has fallen considerably. We replicate several well-known studies in industrial organization and innovation economics and demonstrate how generalized assumptions about the nature of patent citations have misled the field.

The paper is co-authored by Jeffrey M. Kuhn and Alan C. Marco.