The effects of patent trolls

By Paul Walker 28/08/2014


There is a new organisational form, called the non-practicing entity (NPE), in the world of intellectual property. NPEs have recently emerged as a major driver of IP litigation. The idea is that NPEs amass patents not for the sake of producing any actual product, but rather they aim to prosecute infringements of their patent portfolios. (rent-seeking?) The rise of NPEs has sparked a debate regarding their value and their impact on innovation. Proponents argue that imperfections in the legal system implicitly reward large, well-funded organisations, enabling them to infringe at will on small innovators’ IP and that NPEs are there to protect small innovators from such abuse. Opponents cast NPEs as organisations that simply raise the costs of innovation by exploiting the fact that an imperfect legal system will rule in their favour sufficiently often—even if no infringement has actually occurred—that the credible threat of the legal process can yield rents from producing, innovative firms.

So what are the effects of these “patent trolls”? A new NBER working paper, Patent Trolls: Evidence from Targeted Firms by Lauren Cohen, Umit Gurun and Scott Duke Kominers, tries to find out. Cohen, Gurun and Kominers add to the debate on NPEs by providing the first large-sample evidence on precisely which corporations NPEs target in litigation, when NPE litigation occurs, and the impact of NPE litigation on the targeted firms’ innovative activity.

Cohen, Gurun and Kominers argue that there are two reasons that patent trolls can prevent welfare-increasing innovation from being brought to market.

  1. innovators with profitably commercialisable inventions but with a high enough probability of being sued to be deterred from production
  2. innovators that decide not to commercialise because the ex ante expected profitability of becoming a patent troll is higher than that of commercialisation

In their empirical work Cohen, Gurun and Kominers

[…] link patent-level data on NPEs and their activities to data on all publicly traded firms. Using this linked data, we show that NPEs behave opportunistically; that is, typically acting as patent trolls. Specifically: NPEs target firms that are flush with cash (controlling for all other characteristics) and firms that have had recent, positive cash shocks.

Indeed, a one standard-deviation increase in cash level increases the probability of being sued by an NPE by 11% (t = 6.84). Given that the mean probability is 2%, this is more than a fivefold increase.

In fact, NPEs even target conglomerate firms that earn all of their cash from segments having nothing to do with the allegedly infringing patents. For example, an NPE is likely sue a firm regarding a technology patent even if the firm is earning all its revenue from a lumber division entirely unrelated to the allegedly infringing technology patent—even if the division holding that patent is unprofitable. Indeed, we find that profitability in unrelated businesses is almost as predictive of NPE infringement lawsuits as is profitability in the segment related to the allegedly infringing patent.

Consistent with our model, we also find that NPEs target firms against which they have a higher ex ante likelihood of winning. We demonstrate this fact using multiple measures of ex ante likelihood of lawsuit success. First, we show that NPEs are significantly more likely to target firms that are busy dealing with a number of other litigation events unrelated to intellectual property. Being tied up with outside litigation roughly doubles the probability (t = 2.87) of being sued by an NPE. Moreover, we show that, controlling for all other characteristics, firms with larger legal teams have a significantly lower probability of being targeted by NPEs, consistent with large legal teams serving as a deterrent.

Of course, the true prediction of our model is on the ex ante expected profitability of NPE litigation. To capture this, we interact our measures of expected cash payouts with our measures of expected lawsuit success. We find that, as the model predicts, NPEs systematically target those firms for which the ex ante expected profitability of litigation is large. In particular, the payout probability interaction terms are significant and economically large. Our finding suggests that nearly all the firms targeted by NPEs have large pools of cash for potential payouts and are ex ante more likely to pay off in some form (either an out-of-court settlement or an in-court loss). To further explore this connection, we construct a measure of the ex ante expected outcome if a targeted firm were to go to court. This measure relies on the assumption that defendants often make predictions about the likely outcome based on observations of other firms in the same industry and location. We find that the interaction term of this expected outcome and expected payout is again large and significant, providing further evidence that NPEs choose targets based on expected profitability: suits with high probability of payoff against firms with deep pockets.

Non-practicing entities don’t have a monopoly on IP litigation. Practicing entities (PEs), such as IBM and Intel, also sue each other for patent infringement. If our results are simply picking up general characteristics of IP litigation, then we might expect to see PEs behaving in much the same way as NPEs. In order to compare PE and NPE behavior, we hand-collected the universe of patent infringement cases brought by PEs against other PEs in the same period (2001–2011). However, we find the opposite. If anything, PEs are slightly less likely to sue firms with high cash balances and less likely to sue firms with many ongoing cases. All of the other determinants of NPE targeting have (statistically and economically) no impact on PE litigation behavior. This comparison suggests that our results on NPE litigation behavior are not just reflections of general characteristics of IP litigation. Rather, our findings are consistent with agent-specific motivations for NPEs in targeting firms flush with cash just when favorable legal outcomes are more likely.

Lastly, we examine the real impacts of NPEs’ litigation activity. Comparing firms that are sued by NPEs and go to court (and in this way controlling for selection of firms targeted by NPEs), we find that firms that lose in court have significantly lower post-litigation patenting activity and fewer citations to their marginal post-litigation patents, relative to firms whose cases are dismissed. Furthermore, after losing to NPEs, firms significantly reduce R&D spending—both projects inside the firm and acquiring innovative R&D projects outside the firm. Our evidence suggests that it really is the NPE litigation event that causes this decrease in innovation. Prior to litigation, firms that subsequently lose to NPEs are identical to those that subsequently have suits dismissed. They have the same R&D, patenting, and patent quality. Moreover, patents of firms developed pre-litigation continue to accrue citations at exactly the same rate after litigation, whether or not the suit was dismissed. This is in stark contrast to the divergent amount of citations of firms’ post-litigation patents.

In short, NPEs behave as patent trolls.