National policies take varied approaches to encouraging university-based innovation. This paper studies a natural experiment: the end of the "professor's privilege" in Norway, where university researchers previously enjoyed full rights to their innovations. Upon the reform, Norway moved toward the typical US model, where the university holds majority rights. Using comprehensive data on Norwegian workers, firms, and patents, we find a 50 percent decline in both entrepreneurship and patenting rates by university researchers after the reform. Quality measures for university start-ups and patents also decline. Applications to literature on university technology transfer, innovation incentives, and taxes and entrepreneurship are considered.