This paper argues that openness of upstream research does not simply encourage higher levels of downstream exploitation, it also raises the incentives for additional upstream research by encouraging the establishment of entirely new research directions. We test this hypothesis by examining a “natural experiment” in openness within the academic community: NIH agreements signed during the late 1990s that limited the IP restrictions imposed on academics regarding certain genetically engineered mice. Using a sample of engineered mice that are linked to specific scientific papers (some affected by the NIH agreements and some not), we implement a differences-in-differences estimator to evaluate how the level and type of follow-on research using these mice changes after the NIH-induced increase in openness. We find a significant increase in the level of follow-on research. Moreover, this reflects increased exploration of more diverse research paths. Overall, our findings highlight a neglected cost of IP: reductions in the diversity of experimentation that follows from a single idea.