Changes

According the more economic literature, NPEs may be a good thing, as they may increase competition, innovation, lower downstream prices and enhance consumer choice, as Geradin et al. (2012) claim. However, most authors are somewhat neutral. A small literature has explored the role of NPEs in creating a market for intellectual property (IP). This includes Hagiu and Yoffie (2011), Wang (2010), Pohlmann and Opitz (2010), and Merges (2009), as well as more descriptive contributions from McDonough III (2006) and Abril and Plant (2007). The market for ideas papers explore questions like "What accounts for the relative differences between these different patent intermediation models? ", "Can patent intermediaries make the market more liquid, or will the inefficiencies persist? ", and "What are the efficiency implications of the emergence of these intermediaries for the patent market and society at large? ", as in Hagiu and Yoffie (2011), who conclude that patent intermediaries have so far failed to achieve meaningful scale, but that there are reasons to worry about inefficiencies for small firms, large operating companies and end-consumers. Wang (2010) distinguishes between offensive and defensive aggregators, and claims the former will be first to fall to directed legislation, while the second latter will evolve in standard-setting and licensing bodies. Pohlmann and Opitz (2010) reviews just five cases to find that while patent trolls are an efficient way to enforce IPR, their enforcement leads to excessive royalty fees. And Merges (2009) says "All the evidence points to a major incidence of rentseeking, mixed in with the emergence of a perhaps valuable market for independent ideas and inventions.". In work related to the market for ideas, Lu (2011a) claims that NPEs may deliberately assemble portfolios of complements. As such NPEs may act to reduce the anti-commons problem associated with patent thickets. And Beron and Kinsella (2011) suggests that problem of litigation costs for startups might be mitigated by 3rd party litigation.

One important question is how the patents and the enforcement of patent rights vary between NPEs and regular firms. In empirical work Shrestha (2010) finds that "NPEs in fact hold high value patents and do not engage in frivolous litigation as has been alleged by their critics". Similar findings are reported in Miller (2011) who says, "I am surprised to find as much evidence as I have supporting those who argue that NPEs serve a useful role in the patent system and generally do not assert weaker patents then those asserted by other litigation claimants. The evidence suggests NPEs may in fact assist foreigners and individuals in collecting the rewards they are entitled to by current patent law." Though Miller (2011) also warns that NPEs seem to litigate patents with broad claims, business method patents, and patents on emerging technologies more frequently than their practicing counterparts. Risch (2011) is even more supportive of NPEs, saying "There is no uniform story about NPE patents or where they come from. While some are business methods patents, most are not. While some litigated patents come from failed start-ups, most did not. While some patents were initially assigned to licensing NPEs, most were not. Indeed, some extremely large companies - and even the federal government - have turned to the very same NPEs to enforce some patents. Some patents enforced by NPEs are invalid, while most are not. NPEs litigate patents with objective indicia that are similar to other litigated patents and appear to be invalidated about as often as other litigated patents, so long as they are not repeatedly asserted." He concludes by saying "There is one marked difference, however. Individuals may face a significant disadvantage in high-stakes patent litigation unless they allow NPEs to enforce their patents. This means that NPE litigation may be the best way for garage inventors to capitalize on their patents if infringers refuse to license." Fischer and Henkel (2009) suggest that NPE patents are actually of high quality and have a high likelihood of being held up in court. They hint at the endogenous selection of patents into an NPE’s portfolio, but are more concerned with potential inefficiencies that might arise by separating the market for patents from the market for technologies.  On the issue of settlements and royalties, Layne-Farrar and Schmidt (2009) claim that "there is no justification for the presumption that non-integrated patent holders always charge higher royalties than vertically integrated companies. Moreover, even when non-integrated patent holders charge ’higher’ royalties than their vertically integrated counterparts, it does not imply that the rates are ’excessive’ or that the firm is exhibiting troll-like behavior. Rather, non-integrated patent holders naturally require higher royalty earnings because they earn no profits downstream and receive no payments in kind in the form of cross-licenses." Likewise, Mazzeo et al. (2011) provides evidence that settlement to patent trolls might not be excessive. Using a sample of settlements that are not related to trolls (or at trolls aren’t identified), they report that "... it does not appear that a systematic or pervasive problem of excessive patent damage awards exists." They also note that "[o]ver 75 percent of the variation in observed patent award levels can be explained by the assembled information about the cases, litigants, and patents-at-issue. As a result, infringement awards can be said to be highly predictable. Large awards are not excessive outliers with respect to the empirical analysis in this study." Reitzig et al. (2006, 2007) use a more theoretical approach to argue that troll settlements are excessive.  Love (2011) finds that NPEs litigate at a much later point in a patent’s term than practicing entities, and suggests that shortening patent terms might be beneficial. Related papers include Allison et al. (2010) who consider litigation frequency (NPEs are frequently involved in litigation), and Lu (2011b) who consider royalty rates (NPEs charge royalty rates that are not different from practicing companies). Liang (2010) consider whether NPEs forum shop and finds evidence that they do.

The law literature has focused mainly on judicial reform and whether NPE infrigement cases should fall under the property rule or the liability rule. Farrand et al. (2011) and Helm and Lee (2008) tackle judicial reform in the patent system related to NPEs and Jones (2006) considers NPEs head on. Likewise there is a large sub-literature that considers the impact of the eBay/Merx decision from the Superb Court, which effective prevents NPEs, as well as many other inventors, from seeking injunctive relief. Typical papers include Eddings (2005),Golden (2006),Mersino (2007) and Maughan (2012). Helm (2006) explains that Pharmaceutical firms supported the NPE position because the injunctive relief differentially affects different industries ability to innovate, and Casagrande (2006) suggests that true problem at issue was business method patents, and the Supreme Court’s decision missed the mark. Other judicial reform papers include Chan and Fawcett (2005), who considers the 2005 Patent Reform Act; Reitzig et al. (2006) who argues that courts make unrealistic trade-offs in cases involving NPEs (and should be stricter); and Ferrill (2004) who suggests the creation of Patent Investment Trusts. On whether the property rule or the liability rule is appropriate, and whether the liability rule can be contracted around, Sichelman (2011) and Lemley (2011) provide seminal comments. Finally, Hricik (2010) who considers the ethics of representing each side (and suggests the ethical quandary is in representing the infringer, not the NPE).

*Abril, P.S. Plant, R. 2007. The patent holder’s dilemma: buy, sell, or troll? Communications of the ACM, vol. 50 50 (1), pp. 36-44.[http://www.edegan.com/pdfs/Abril%20Plant%20(2007)%20-%20The%20patent%20holders%20dilemma.pdf pdf]*Allison, Lemley Walker2010allisonpatent Allison, J.R., Lemley, M.A., Walker, J. 2010. Patent quality and risk aversion among repeat patent litigants.*Beron, B[http://www.Ledegan. com/pdfs/Allison%20Lemley%20Walker%20(2010)%20-%20Patent%20Quality%20and%20Risk%20Aversion%20Among%20Repeat%20Patent%20Litigants.pdf pdf]*Beron, B.L. Kinsella, J.E. 2011. David vs. goliath patent cases: A search for the most practical mechanism of third party litigation financing for small plaintiffs. N. Ky. L. Rev., vol. 3838, pp. 605-687.*Casagrande, T.L. 2006. The reach of ebay inc. v. mercexchange, llc: Not just for trolls and patents. Hous. Law., vol. 4444, pp. 10-11.*Chan, J[http://www.edegan. com/pdfs/Casagrande%20(2006)%20-%20The%20Reach%20of%20eBay%20Inc%20v%20MercExchange%20LLC.pdf pdf]*Chan, J. Fawcett, M. 2005. Footsteps of the patent troll. Intell. Prop. L. Bull., vol. 1010, p. 11.*Chien, C[http://www.Vedegan. 2008com/pdfs/Chan%20Fawcett%20(2005)%20-%20Footsteps%20of%20the%20Patent%20Troll.pdf pdf]*Chien, C.V. 2008. Of trolls, davids, goliaths, and kings: Narratives and evidence in the litigation of high-tech patents. NCL Rev., vol. 8787, p. 1571.*Chien, C[http://www.V. 2010edegan.com/pdfs/Chien%20(2008)%20-%20Of%20Trolls%20Davids%20Goliaths%20and%20Kings.pdf pdf]*Chien, C.V. 2010. From arms race to marketplace: The new complex patent ecosystem. Hastings Law Journal, vol. 6262.*Cooper Feldman, R[http://www. Ewing, Tedegan. 2011. The giants among uscom/pdfs/Chien%20(2010)%20-%20From%20Arms%20Race%20to%20Marketplace.pdf pdf]*EddingsChuang, RA. 20052006. 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Elves or trolls? the role of non-practicing entities: Being on patent owners in the receiving end matters tooinnovation economy. Santa Clara Computer & High Tech. LJIndustrial and Corporate Change, vol. 2721 (1), pp. 79373-79394.[http://www.edegan.com/pdfs/Geradin%20LayneFarrar%20Padilla%20(2012)%20-%20Elves%20or%20Trolls.pdf pdf]*JonesGolden, J.M. 2006. Permanent injunction, a remedy by any other name is patently not the same: How ebay v. mercexchange affects the patent right of non-practicing entities. GeoPatent trolls and patent remedies. Tex. Mason L. Rev., vol. 1485, p. 10352111.[http://www.edegan.com/pdfs/Golden%20(2006)%20-%20Patent%20Trolls%20and%20Patent%20Remedies.pdf pdf]*Layne-FarrarGregory, AJ.K. 20122006. The brothers grimm book of business models: A survey of literature and developments in patent acquisition and litigation.*LemleyTroll next door, Mthe. 2011J. Contracting around liability rulesMarshall Rev.*Lemley, M.A. 2007. Are universities patent trolls. 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Myth of the patent trollLegal ethics and non-practicing entities: An alternative view of the function of patent dealers in an idea economy, Being on thereceiving end matters too. Emory LJSanta Clara Computer & High Tech. LJ, vol. 5627, ppp. 189793-793.*MergesJones, RM.P2006. 2009. The trouble with trolls: InnovationPermanent injunction, renta remedy by any other name is patently not the same: How ebay v. mercexchange affects the patent right of non-seeking, and patent law reformpracticing entities. Berkeley TechGeo. Mason L. Rev. LJ, vol. 2414, ppp. 1035. [http://www.edegan. 1583com/pdfs/Jones%20(2006)%20-1647%20Permanent%20Injunction%20A%20Remedy%20by%20Any%20Other%20Name%20is%20Patently%20Not%20the%20Same.pdf pdf]*MersinoLayne-Farrar, PA.M2012. 2007. Patents, trolls, The brothers grimm book of business models: A survey of literature and personal property: Will ebay auction away a patent holder’s right to excludedevelopments in patent acquisition and litigation. 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Below are the most cited economic papers included in the references of the NPE papers in this review. I have grouped them into three groups. In the first group is the literature that outlines markets for technologies, the existence and characteristics of patent thickets, the suggests that patents are 'probabilistic' (perhaps arising from failures at the patent office). Also included in this group is Josh Lerner's "Trolls on State Street" paper, which was very heavily referenced, and provides the seminal reference for the economic concept of a troll (as far as I can see). I will review Josh's paper shortly.

In the second group, is are the broader references that back up the first group. The same themes are present, but generally less developed. Also included in this group is some key papers from the patent pools literature and the litigation of patents literature (the economic branch of it anyway). These are two literatures are complementary to the NPE literature, but distinctfrom it. They also build of off the papers in the first group. And in the third group is the 'classics'. These are universally referenced and fundamental building blocks.

I estimate that the four five most cited papers in the literature (all included in the first group) are: