Invalid but infringed? An analysis of the bifurcated patent litigation system
研究了分离式与非分离式专利诉讼系统的权衡，利用德国和英国的数据发现分离系统下专利被认定侵权后可能被无效，且被告更少挑战专利有效性，尤其资源受限的被告，同时更易和解。
In bifurcated patent litigation systems, claims of infringement and validity of a patent are decided independently of each other in separate court proceedings at different courts. In non-bifurcated systems, infringement and validity are decided jointly in the same proceedings at a single court. We build a model that shows the key trade-off between bifurcated and non-bifurcated systems and how it affects the incentives of plaintiffs and defendants in patent infringement cases. Using detailed data on patent litigation cases in Germany (bifurcated) and the U.K. (non-bifurcated), we show that bifurcation creates situations in which a patent is held infringed that is subsequently invalidated. We also show that having to challenge a patent's validity in separate court proceedings under bifurcation implies that alleged infringers are less likely to do so. We find this to apply in particular to more resource-constrained alleged infringers. Finally, we find parties to be more likely to settle in a bifurcated system.