| Abstract: | 
How do non-practicing entities ("Patent Trolls") impact innovation and 
technological progress? Although this question has important implications for 
industrial policy, little direct evidence about it exists. This paper provides 
new theoretical and empirical evidence to fill that gap. In the process, we 
inform a debate that has historically portrayed non-practicing entities (NPEs) 
as either "benign middlemen", who help to reallocate IP to where it is most 
productive, or "stick-up artists", who exploit the patent system to extract 
rents and thereby hurt innovation. We employ unprecedented access to 
NPE-derived patent and financial data, as well as a novel model that guides 
our data analysis. We find that NPEs acquire patents from small firms and 
those that are more litigation-prone, as well as ones that are not core to the 
seller's business. When NPEs license patents, those that generate higher fees 
are closer to the licensee's business and more likely to be litigated. We also 
find that downstream innovation drops in fields where patents have been 
acquired by NPEs. Finally, our numerical analysis shows that the existence of 
NPEs encourages upstream innovation and discourages downstream innovation. The 
overall impact of NPEs depends on the share of patent infringements that come 
from non-innovating producers. Our results provide some support for both views 
of NPEs and suggests that a more nuanced perspective on NPEs and additional 
empirical work are needed to make informed policy decisions. |