Abstract

One of the more curious features of patent law is that patents can be challenged by anyone worried about being sued. This challenge right allows potential defendants to file a declaratory relief lawsuit in their local federal district court, seeking a judgment that a patent is invalid or noninfringed. To avoid this home-court advantage, patent owners may file a patent infringement lawsuit first and, by doing so, retain the case in the patent owner's venue of choice. But there is an unfortunate side effect to such preemptive lawsuits: they escalate the dispute when the parties may want to instead settle for a license. Thus, policies that allow challenges are favored, but they are tempered by escalation caused by preemptive lawsuits. To the extent a particular challenge rule leads to more preemptive lawsuits, it might be disfavored.

This Article tests one such important challenge rule. In MedImmune v. Genentech, the Supreme Court made it easier for a potential defendant to sue first. Whereas the prior rule required threat of immediate injury, the Supreme Court made clear that any case or controversy would allow a challenger to file a declaratory relief action. This ruling had a real practical effect, allowing recipients of letters that boiled down to "Let's discuss my patent" to file a lawsuit when they could not before.

This was supposed to help alleged infringers, but not everyone was convinced. Many observers at the time predicted that the new rule would lead to more preemptive infringement lawsuits filed by patent holders. They would sue first and negotiate later rather than open themselves up to a challenge by sending a demand letter. Further, most who predicted this behavior—including parties to lawsuits themselves—thought that nonpracticing entities ("NPEs") would lead the charge. Indeed, as time passed, most reports suggested that this is exactly what happened: that patent trolls uniquely were suing first and negotiating later. But to date, no study has empirically considered the effect of the MedImmune ruling to determine who filed preemptive lawsuits. This Article tests MedImmune's unintended consequences. The answer matters: lawsuits are costly, and while "quickie" settlements may be relatively inexpensive, increased incentive to file challenges and preemptive infringement suits can lead to entrenchment instead of settlement. 

Using a novel longitudinal dataset, this Article considers whether MedImmune led to more preemptive infringement lawsuits by NPEs. It does so in three ways: first, it performs a differences-in-differences analysis to test whether case duration for the most active NPEs grew shorter after MedImmune. One would expect that preemptive suits would settle more quickly because they are proxies for quick-settlement cases rather than signals of drawn-out litigation. Second, it considers whether, other factors equal, the rate of short-lived case filings increased after MedImmune. That is, even if cases grew longer on average, the share of shorter cases should grow if there are more placeholders. Third, it considers whether plaintiffs themselves disclosed sending a demand letter prior to suing.

It turns out that the conventional wisdom is wrong. Not only did cases not grow shorter, cases with similar characteristics grew longer after MedImmune. Furthermore, NPEs were not the only ones who sued first and negotiated later. Instead, every type of plaintiff sent fewer demand letters—NPEs and product companies alike. If anything, the MedImmune experience shows that everyone likes to sue in their preferred venue. As a matter of policy, it means that efforts to dissuade filing lawsuits should be broadly targeted because all may be susceptible.

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