Patent race models assume that an innovator wins the only patent covering a product. But when technologies are complex, this property right is defective: ownership of a product's technology is shared, not exclusive. In that case I show that if patent standards are low, firms build "thickets" of...

We use detailed data to estimate the private costs and private rents of United States patents for publicly-traded firms. In analyzing costs, we first introduce a novel theoretical model to interpret our estimates. We then combine lawsuit data from Derwent Litalert with non-practicing entity...

Does the disclosure requirement of the patent system encourage the diffusion of inventions? This paper builds a simple model where firms choose between patents and trade secrecy to protect inventions. Diffusion is not necessarily more likely with a patent system nor is the market for technology...

When innovation is cumulative, early patentees can hold up later innovators. Under complete information, licensing before R&D avoids holdup. But when development costs are private information, ex ante licensing may only occur in regimes with sub-optimal patent policy

Does the disclosure requirement of the patent system encourage the diffusion of inventions? This paper builds a simple model where firms choose between patents and trade secrecy to protect inventions. Diffusion is not necessarily more likely with a patent system nor is the "market for...

When innovation is cumulative, early patentees hold claims against later innovators. Then potential hold-up may cause prospective second stage innovators to forego investing in R&D. It is sometimes argued that ex ante licensing (before R&D) avoids hold-up. This paper explores ex ante licensing...