Patent Assertion Entity Activity

defendants that will arise in the lawsuit. 82 A PAE that would have joined five accused infringers as
defendants in a single lawsuit pre-AIA might instead file five separate lawsuits post-AIA because of the
anti-joinder rule. Or that PAE might still file one lawsuit, but only against a single accused infringer
because of the new rule.
Two recent studies have examined whether the AIA has affected the share of patent infringement
suits filed by NPEs or PAEs. Feldman et al. (2013) considered this possible effect in their analysis of
patent cases filed in 2012. They reported that the number of defendants sued by PMEs declined
following passage of the AIA, which, in their view, “may suggest that changes in the [AIA] had at least
some initial success in encouraging patent monetization entities not to cast their nets so widely.” 83 But
even with the AIA, they noted, patent cases filed by PMEs were still much higher in 2012 than they
were in 2007 and 2008. 84
Christopher Cotropia, Jay Kesan, and David Schwartz (2014) also studied the effect of the AIA on PAE
litigation activity. 85 They collected 2,520 infringement lawsuits filed in 2010 and 5,185 lawsuits filed in
2012 and coded each plaintiff into one of eight entity types: operating company, university, individual
inventor, patent aggregator, technology development company, failed start-up, IP holding subsidiary of
an operating company, or patent holding company. 86 Despite the fact that 2012 saw twice as many
filed cases as 2010, Cotropia et al. found essentially no change in the number of unique patent holders
that initiated patent infringement suits (1,667 versus 1,588) or in the number of unique defendants
(9,419 versus 9,894). 87 Consequently, the authors concluded that the increase in the number of filed
cases could likely be attributed in large part to the AIA’s anti-joinder rule. 88 Cotropia et al. found that
82
Id. § 19(d), 125 Stat. at 332 (codified at 35 U.S.C. § 299).
83
Feldman et al., supra note 2, at 7.
84
Id.
85
Cotropia et al., supra note 2.
86
Id. at 654. Patent aggregators and patent holding companies filed 448 cases in 2010 and 2,278 cases in 2012.
87
Id. at 675–76, 678.
88
Id. at 683 (“One way to consider this is that the AIA has added substantial cost to the system, by increasing the number of
lawsuits, without decreasing the number of patentees or defendants.”).
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