Hall, Bronwyn H. MPI for Innovation and Competition, Max Planck Society;
http://www.nber.org/papers/w21455 (Preprint)
https://doi.org/10.1093/oep/gpaa034 (Publisher version)
Hall, B. H., Helmers, C., & von Graevenitz, G. (2017). Technology Entry in the Presence of Patent Thickets. NBER Working Paper Series, 21455.