Using our own data on Artificial Intelligence publications merged with Burning Glass vacancy data for 2007-2019, we investigate whether online vacancies for jobs requiring AI skills grow more slowly in U.S. locations farther from pre-2007 AI innovation hotspots. We find that a commuting zone...

Technological breakthroughs occasionally set off floods of inventions and associated patents. The decline of the business method exception to patentability is likely to increase the frequency of patent floods. Future technological breakthroughs might now cause two different patent floods: a...

International comparisons of patent systems are essential to harmonization treaties and to analyze economic growth. Yet these comparisons often rely on little but conventional wisdom. This paper develops an empirical method to compare the economic strength and quality of patent systems by using...

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

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...

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...