Patents vs trade secrets: knowledge licensing and spillover

We develop a model of two-stage cumulative research and development (R&D), in which one Research Unit (RU) with an innovative idea bargains to license her nonverifiable interim knowledge exclusively to one of two competing Development Units (DUs) via one of two alternative modes: an Open sale after patenting this knowledge, or a Closed sale in which precluding further disclosure to a competing DU requires the RU to hold a stake in the licensed DU’s post-invention revenues. Both modes lead to partial leakage of RU’s knowledge from its description, to the licensed DU alone in a closed sale, and to both DUs in an open sale. We find that higher levels of interim knowledge are more likely to be licensed via closed sales. If the extent of leakage is lower, more RUs choose open sales, generating a non-monotonic relationship between the strength of Intellectual Property Rights (IPR) and aggregate R&D expenditures and the overall likelihood of development by either DU