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`A Window into Expectations of the World Technological Frontier
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`Honors Thesis
`Alexander M. Bell∗
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`Departments of Economics and Computer Science
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`Brown University
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`Abstract
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`A “submarine patent” is one whose issuance and publication has been intentionally delayed
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`by its inventor with the hope that firms will independently discover and come to rely on
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`a similar innovation at some later time, at which point the inventor causes his patent to
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`issue and claims infringement. Although submarine patents are harmful to an innovation-led
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`economy, previous research has struggled with how to discriminate between these subversive
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`patents and patents whose issuance was delayed for legitimate reasons. I propose a novel
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`identification strategy that exploits self-sorting by inventors around a 1995 policy change
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`that was unfavorable to submarine patents. Using a regression-discontinuity design, I find
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`that submarine patents are on average much more likely to be asserted for infringement in
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`court cases. In addition, I conclude that submarines were more common in certain industries
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`than others as evidenced by differential responses of industries to the policy change. Finally,
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`I show that the failure of submarine patents within specific industries to ultimately assert
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`infringement seems to be an indicator of which industries in the world economy experienced
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`shifts in technological paradigms during this time, providing an additional method to asses
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`the determinants of differences in income per capita across countries. I also describe how this
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`result can be generalized across timeperiods.
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`April 17, 2013
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`∗The author acknowledges the guidance of his thesis advisor, Oded Galor, and comments from his reader in the computer
`science department, Tom Doeppner. The author is also grateful for helpful comments from Erez Yoeli and a number of friends,
`including those in other disciplines who helped relate these findings to the nature and history of technological progress in other
`fields. Finally, the author acknowledges previous work that laid the framework for this paper while studying the patent backlog
`at the USPTO in combination with Alan Marco, Stu Graham, and Conny Chen.
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`
`
`Alex Bell
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`1 Introduction
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`An Autopsy on Submarine Patents
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`A little-known Texas-based company filed a patent infringement complaint against social gaming giant Zynga
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`in early 2012, alleging infringement on four patents. The issue dates of Personalized Media Communications’
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`four patents were between June of 2010 and March of 2011, but all were filed in 1995: one on May 23, one
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`on June 6, and two on June 7.
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`These four patents, and others like them, are sometimes termed “submarine patents.” This term refers
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`to a patent whose inventor does not wish to market his invention. Instead, after filing his non-public patent
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`application, the inventor hopes for another inventor to discover the same invention and develop it into a
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`successful product. When this happens, like a submarine emerging from the depths, the inventor finishes
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`the paperwork for his patent to issue and sues the now-infringing producer for a share of his profits.
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`Submarine patenting can be thought of in the context of the free-rider problem. If the costs of developing
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`an invention into a marketable good are high, an inventor might choose to wait for another firm to invest in
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`development, then extract royalties from that firm’s success. Submarine patenting may also be considered
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`to cause a deadweight loss to society in the sense that some fraction of innovators who wish to sell their
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`products must pay an additional “tax” on their products to submarine patenters.
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`The economic rationale for patents is to encourage innovation. The government grants a fixed-term
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`monopoly to an inventor in exchange for fully disclosing his invention early so that society might learn from
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`it. At the same time, there are standards for patentability. Patents must be useful, novel, and non-obvious.
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`The applicant carries the burden of proof of patentability, but the US Patent and Trademark Office would
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`not be doing its job of aiding innovation if it risked disenfranchising inventors of their patents. Thus, if an
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`inventor botches his application, he is given leniency to amend it without fear of losing his patent rights to
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`others who would file after his original application. Section 2 discusses other legitimate reasons why a patent
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`application may be delayed in more depth.
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`This paper proposes a novel strategy for identifying a large group of submarine patents. I first show that
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`patent applicants intending to take advantage of this loophole self-sorted to file before a policy change that
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`made submarining future patents infeasible. Having shown that patents on either side of the discontinuity
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`are similar in all ways other than their likelihood of being submarine patents, I examine characteristics
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`of submarine patents and find that they are on average much more likely to be involved in infringement
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`litigation. However, I find starkly different litigation outcomes for different industry classes, and conclude
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`that this is due to shifts in technological paradigms within certain industries.
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`I discuss the relevance of
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`submarine patents to measure the expectations of technological change and provide a strategy to generalize
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`the results of this paper to construct a measure of technological expectations and identify shifts in techno-
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`1
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`Alex Bell
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`An Autopsy on Submarine Patents
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`logical paradigms over time and within industries. Such information can be useful for assessing differences
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`in income across countries if economies that are engaged in the use of technologies that undergo paradigm
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`shifts benefit from such technological revolutions.
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`The remainder of this paper is as follows. Section 2 provides background on the policy change and a
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`review of literature within the economics of innovation. Section 3 describes the dataset of patent grants I have
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`compiled including outward linkages to outcomes such as litigation. Section 4 puts forward a theoretical
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`model for submarining and testable hypotheses. Section 5 conveys my findings, while Section 6 offers
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`discussion of the wider implications of these findings to studying the economics of innovation and Section 7
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`finally concludes.
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`2 Background and Motivation
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`This section describes the history of the submarine loophole before proceeding to survey relevant literature.
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`2.1 A 21st Century Vantage Point
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`In order for a patent system to be susceptible to submarine patents, I argue that it must have two traits:
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`(1) While the patent application is pending, other firms must have no knowledge of it. If they do, they will
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`not use the technology.
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`(2) Regardless of how long the patent pends for, once granted it must have a long enough term of force to
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`be worth enforcing against profitable firms that rely on the invention.
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`Issue (1) was resolved by the American Inventors Protection Act of 1999. Since 2000, most US applications
`are published 18 months after filing, regardless of their status as denied, issued, or still pending.∗ This policy
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`change seems to have been aimed at bringing the US in line with what other countries were doing, speeding
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`the diffusion of knowledge, and reducing the feasibility of submarine patents.
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`Issue (2), however, was resolved earlier, when an agreement was signed by member nations of what was to
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`become the World Trade Organization in 1994. With the goal of a more globally homogeneous system of IP
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`enforcement to foster international trade, the Agreement on Trade-Related Aspects of Intellectual Property
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`Rights contained a number of standards for laws pertaining to copyright, patenting, and other intellectual
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`property.
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`One of the many standards introduced was a harmonization of patent term. TRIPS, agreed on near the
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`end of the 1994 Uruguay Round of the General Agreement on Tariffs and Trade (GATT), mandated that
`∗There are a few exceptions to mandatory application publication, the most notable of which occurs when applicants certify
`that they do not intend to file for the same invention in other countries.
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`2
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`Alex Bell
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`An Autopsy on Submarine Patents
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`WTO members grant patent protection of at least 20 years, starting the clock at the filing date of a patent.
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`Prior to TRIPS, applicants in the US were granted a patent term of 17 years from issue date. President
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`Clinton signed the GATT on December 8, 1994, with patent term reforms set to take effect six months later,
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`on June 8.
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`The effect of the policy change was a tremendous flood of patent applications just prior to the shift. On
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`June 7, ten times as many applications were filed as any other day excluding the month leading up. The
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`Appendix contains a press release from the USPTO from June 28 explaining that it received a quarter of
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`the year’s projected filings in just nine days. From the vantage point of 1995, this is a curious anomaly. But
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`now that most of these applications have either issued or been abandoned, we see that this cohort of patent
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`applications differs in important ways from other cohorts, and I will argue in Section 4 that it offers a unique
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`window into the behavior of submarine patents.
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`2.2 Related Literature
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`This section begins with a survey of metrics that other studies have used to measure patent value, then
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`discusses ways that economists believe inventors appropriate revenue from their inventions in different in-
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`dustries. After a brief summary of the sparse literature on submarine patents, I overview the vast literature
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`concerned with the effects on the economy of differing rates of technological progress.
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`2.2.1 Measures of Patent Value
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`The patent literature is rich with a variety of metrics for patent value and quality. Much of the earliest
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`work in defining the roll of patent statistics within economics was done by Griliches (1991) and others at
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`the NBER’s research program in productivity. The underlying motive was to better understand economic
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`processes that lead to productivity gains – pursuing “the dream of getting hold of an output indicator of
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`inventive activity,” in Griliches’ words. Following after Scherer (1984), who linked 15,000 patents to the
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`443 largest US manufacturing firms in the FTC’s Line of Business Survey, Griliches and others explored
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`outward linkages to R&D figures and stock market data for publicly traded corporations. 16 Griliches (1991)
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`summarizes that a strong relationship can be identified at the cross-sectional level between R&D expenditure
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`and the number of patents a firm has received. He further concludes that there may be evidence of diminishing
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`returns to R&D expenditures. 8
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`Hall, Jaffe, and Trajtenberg (2001) provide a more modern approach to patent data characteristic of
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`the growing availability of digital information, particularly for patents. Of the 400 three-digit classes the
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`USPTO groups patents into, the authors condensed the data into 36 two-digit technological sub-categories,
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`An Autopsy on Submarine Patents
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`and ultimately into six higher-level categories: Chemical (excluding drugs), Computers and Communica-
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`tions, Drugs and Medical, Electrical and Engineering, Mechanical, and Others. However, their study reflects
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`the difficulties of others who have attempted similar groupings, and they suggest that “while convenient,
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`the present classification should be used with great care, and reexamined critically for specific applications.”
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`They also discuss the usefulness of backward citations (citations a patent makes) as constituting a “paper
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`trail” to measure knowledge spillovers and forward citations (citations received) as indicative of the “im-
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`portance” of a patent. They put forward new measures in the form of Herfindahl concentration indices:
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`Generality – the percentage of citations a patent makes in classes other than its own – and Originality – the
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`percentage of citations received from other classes. They briefly discuss some validation strategies for these
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`metrics. For example, Computers and Communications scores high on Generality, consistent with the view
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`that it is a general purpose technology, and high on originality, in accordance with a view that it tends to
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`break traditional models in terms of innovation. 11
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`Hall, Jaffe, and Trajtenberg (2000) provide further insight into outside linkages of patent data. The study
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`found that, in predicting firms’ market value from patent counts, weighting patents by their citation counts
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`could better predict firms’ market value, indicating that forward citations are in some way tied to a notion
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`of a patent’s “value.” 10
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`In a different vein, a comprehensive survey by Scherer and others of US and German firms found payment
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`of renewal fees to be a reliable proxy for patent value. They also confirm that the distribution of patent
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`values is highly skewed, with a few patents being extremely profitable. 17
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`Table 1 summarizes and expands upon a dichotomy proposed in van Zeebroeck et al (2008), which
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`classifies the strategies used by economists to view patent data as either patent-based or market-based. 18
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`Many of these techniques are revisited in Section 4, in which the feasibility and applicability of their use for
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`this project are discussed.
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`2.2.2 Appropriability of Inventions
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`Within the field of economics, two major investigations have been carried out into how firms appropriate
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`rents from their innovations. The first, published in 1987, was a survey of 650 R&D executives in 130 different
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`lines of business (as defined by the FTC). It is sometimes referred to as the Yale survey. 13 The second was
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`administered in 1994 to 1478 R&D labs, and is sometimes referred to as the Carnegie Mellon survey. 5
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`The Yale survey divided its questions into product and process patents.
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`In general, firms reported
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`capturing profits from product innovations with patents more often than with process innovations, perhaps
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`because it is more difficult (and less desirable) to keep product innovations secret. For processes, lead time
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`and learning advantages were rated much more useful than patents. In general, patents were rated more
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`4
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`Alex Bell
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`An Autopsy on Submarine Patents
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`Table 1: Established Metrics of Patent Value and Related Dimensions
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`Metric
`—Patent-Based —
`Backward Citations
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`Forward Citations
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`Generality
`Originality
`Maintenance fee payments
`Legal disputes
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`Parents
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`—Market-Based —
`Firm value
`Estimated patent value
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`Description
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`citations the patent makes; commonly used to track knowledge
`spillovers
`citations the patent receives; generally accepted to be measure of
`“importance”
`diverse classes of forward citations
`diverse classes of backwards citations
`indicator of how much owner values patent
`incidences and outcomes of infringement suits; usually believed to
`be indicative of valuable patents
`count of parents or earliest parent’s filing date to show “entrance”
`into system
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`Stock market performance, R&D statistics, Tobin’s q
`Royalties, valuation by inventors or managers, buy-outs
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`important to businesses for preventing duplication by competitors than for amassing royalties. The industries
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`that reported relying on patents the most to capture revenues on their innovations were chemicals and drugs,
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`perhaps because in those industries, infringement is more clear-cut. The authors found that responses to
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`their appropriability survey were consistently significant predictors of industries’ R&D intensities.
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`The Carnegie Mellon survey some years later asked similar questions to the Yale survey, but extended the
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`investigation into why firms use patents, even if they are not a valuable means of protecting their inventions
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`(as most industries indicated). The most common reasons for not patenting were ease of inventing around
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`products and concern over disclosing the invention. For small firms, the cost of defending their patents was
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`a commonly raised issue. In examining individuals’ responses as to why their firms patent, the authors saw
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`two groups naturally emerging. They define “complex” industries as those in which new products typically
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`contain many patented inventions (eg, electronics) compared to “discrete industries” such as drugs and
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`chemicals. Respondents in discrete industries tended to report use of patents not only for maintaining a
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`monopoly on their innovations, but also to block rivals’ entry via similar inventions (“patent fences”). In
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`contrast, the bulk of respondents who reported using patents to enter into licensing negotiations were in
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`complex industries.
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`2.2.3 Submarine Patents
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`A limited literature exists within economics on issues relating to submarine patents. It seems the reason for
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`the dearth of research on this topic is that submarine patents are generally difficult to identify.
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`Graham and Mowery (2002) was one of the first papers within economics to analyze the effect of the
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`patent application continuation process. A continuation is a legal term within patenting; it allows a rejected
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`application to be restarted while claiming its original priority (filing) date. Of note, they found an increase in
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`the use of continuations prior to 1995, with a sharp drop-off for applications filed after. They reported that
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`software companies seemed to be using the continuations process the most. They also found continuations to
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`be positively correlated with the number of forward citations, patent originality, and incidence of post-grant
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`litigation (as measured by linkages to the Derwent patent litigation database). 7
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`Hegde, Mowery, and Graham (2007) use more recent data, current as of 2004 (the NBER patent database
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`described in Hall, Jaffe, and Trajtenberg (2001)). They describe the uniqueness of continuations to the US
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`patent system and their suspected involvement with submarine patents. At the same time, they explain the
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`stance of some patent attorneys and industry groups: these long-pending continued applications may also
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`be the result of “high-risk investments of ‘pioneering inventors’ in ‘young’ fields of invention that are subject
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`to uncertainty.” They admit that little empirical evidence has been brought to bear on the characteristics of
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`those applicants who exploit the US continuation process. The paper empirically examines which types of
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`industries have used different types of continuations: Continuations, Continuations in Part, and Divisionals.
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`All three types introduce a delay in the application process while allowing the final patent to retain the
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`priority date of the initial application. 12
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`2.2.4 “Skill-Biased” Technical Change
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`A number of studies, particularly in the 1990s and early 2000, have attempted to account for the growing wage
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`gap observed in developed countries between skilled and unskilled workers. The gap can be characterized by
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`an increase in wages of skilled (educated) workers above those of the unskilled, accompanied by a growing
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`abundance of skilled workers in the labor force relative to unskilled. 2
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`A concept of “skill-biased technical change” became a prominent explanation. The theory was that
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`certain types of workers may fair better than others during periods of rapid technological growth. Namely,
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`economists hypothesized that more educated or otherwise more able workers could better adjust to changing
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`workplaces. This increase in demand for skilled workers could account for the relative rise in returns to skill
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`in the midst of a relative increase in supply of skilled workers.
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`Caselli divides technological revolutions into two categories: skill-biased (eg, the information technology
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`revolution) and de-skilling (eg, the assembly line, which replaced skilled artisans in the production of cars).
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`With the focus of modeling skill-biased revolutions, he develops a model in which productivity-augmenting
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`technology spurs increases in wages, but particularly so for quick-learning workers, while the slow-learning
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`workers continue to use the old technology for a certain period of time (the old capital is not immediately
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`valueless). He confirms that recent increases in wage inequality within industries are in fact associated with
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`Alex Bell
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`An Autopsy on Submarine Patents
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`increased inequality of capital-to-labor ratios. Furthermore, he theorizes that education may make workers
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`better able to adjust to new technology; if this is the case, then technological revolutions within an industry
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`would increase the returns to education for workers in those industries. 3
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`In another model of technological change and wages, Galor and Moav theorize that regardless of whether
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`a technological revolution ultimately brings about a new paradigm that is biased toward or away from skill
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`(or ability), in the short run the transition to this new technological state will be skill (ability)-biased in
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`the short turn. Their model predicts several effects that are confirmed by data. 6
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`Machin and van Reenen used R&D intensities in the manufacturing sectors of seven OECD countries
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`as a proxy for technological change. They found strong results across developed nations that industries
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`experiencing technical change also experience a shift in composition of their labor forces favoring skilled
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`workers, and conclude that this evidence is in line with the skill-biased technical change hypothesis. 14
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`In a similar vein, Berman, Bound, and Machin address the spread of skill-biased technical change through-
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`out the world economy. Using similar industry-level manufacturing data, they examine within-industry
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`changes among developed countries in the skilled-to-unskilled labor ratio. They find that industry changes
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`are highly correlated among countries. This is strong evidence that skill-biased technical change within
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`industries is not localized to the country from which the technology originates, but rather the change per-
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`meates throughout the industry and affects workers in the broader world economy. The authors also offer
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`some evidence that skill-biased technical change may account for a trend of skill upgrading witnessed in the
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`manufacturing sectors of less-developed countries. 2
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`Bartel and Sicherman use a wide array of measures for technical change in manufacturing industries,
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`including use of patents, investment in R&D, and various measures of TFP (ie, residuals from estimating
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`sales after controlling for capital). Tracking workers through the National Longitudinal Survey of Youth,
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`the authors find that after controlling for individual-level fixed effects, the relationship relationship between
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`wages and technological change is weakened. They conclude that a significant part of industry-level changes
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`in wage inequality and skill composition is due to sorting by workers who move between industries. 1
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`A major limitation of studies examining technological change on industry wages and skill compositions
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`has been a tendency to rely exclusively on trends in the manufacturing sector, where statistics such as
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`industries’ R&D expenditures to sales ratios, total factor productivity, and wages are easiest to measure
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`and most freely available from the government due to the manufacturing sector’s relevance to economic
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`indicators. 9 With the method proposed in my paper to identify technological revolutions, combined with the
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`increased use of individual-level tax data on earnings within economics, 4 it may soon be possible to extend
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`the literature beyond the manufacturing industry.
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`Alex Bell
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`3 Data
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`An Autopsy on Submarine Patents
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`We ourselves do not put enough emphasis on the value of data and data collection in
`our training of graduate students and in the reward structure of our profession. It is
`the preparation skill of the econometric chef that catches the professional eye, not the
`quality of the raw materials in the meal, or the effort that went into procuring them.
`(Zvi Griliches, address to the American Economic Association, January 4, 1994 9)
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`In this following section, I summarize my ingredients.
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`3.1 My data
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`The USPTO has made remarkable strides in the past few years toward making raw patent data available to
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`researchers. With this much data, the next question economists are confronting is what can be done with
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`it. I first discuss what I have done with it, then what others are doing.
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`Through a partnership with Google, the USPTO has made available the full text of every patent granted
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`from January 1976 to present (updated weekly). To download the data, one must download and unzip nearly
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`2,000 weekly files. None of these files are in formats that are useful to any type of research that economists
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`would be interested in.
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`There are four different file formats, spanning different timeperiods of operation:
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`.txt (1365 files from 1976-2001). These are text files that are organized in some vaguely
`1. pftaps
`hierarchical manner. Certain text strings recursively separate different data fields.
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`2. pg
`.sgm (54 files mid-2001 and a few in 2002). These files are in Standardized Generalized Markup
`Language, an ISO standard that is similar in some ways to XML.
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`.xml (156 files 2002-2004). Similar to above, but somewhat more compatible with modern XML
`3. pg
`readers.
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`4. ipg
`.xml (currently about 400 files, from 2005-present). The most recent XML generation. Names
`of tags were redone to be more descriptive.
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`Weekly patent grant files were parsed in Python with a script run over the course of several days.
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`Figure 1 presents a stylized Entity-Relationship model of how I conceptualize the data contained within
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`a patent grant.
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`In translating the data from a docuement-oriented model to the relational model, my
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`ultimate goal was to produce a relational database in Boyce-Codd Normal Form – that is, one without
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`unnecessary duplication of data. However, determining the data’s functional dependencies has proven more
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`complex than expected. For example, we know the filing date for all five million patents in the database –
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`let this be contained in the relation BasicInf o(patent, f iling date, issue date), in which the primary key
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`is underlined. Yet when a citation is recorded within a patent grant, the USPTO lists not only the cited
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`patent’s number, but also the cited patent’s application and issue dates.
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`If we have a relation linking a
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`patent to its citations, Cites(patent, cited patent), storing the application and issue dates of cited patent
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`Alex Bell
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`An Autopsy on Submarine Patents
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`Figure 1: Entity-Relationship Diagram of Available Data
`Compustat linkages discussed in next section
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`Diagram.png
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`in that relation seems redundant, because this information can be assembled by joining the relations on
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`BasicInf o.patent = Cites.cited patent. Given that the dataset contains five million patents but 55 million
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`citations, this kind of duplication would be enormously costly. However, this foreign key relationship does
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`not always hold true: a cited patent may have been issued prior to 1976, or it may be a patent in another
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`country. If either of these is the case, its filing and issue dates would not be contained in the Cites relation.
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`Similar problems exist in recording details of patents associated with parent relationships and elsewhere in
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`the construction of the relational database. When confronted with these dilemmas, I generally erred on the
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`side of preserving information, at the risk of redundancy.
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`Another takeaway of Figure 1 is the many-to-many cardinalities that tend to characterize patent data.
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`One patent may have many inventors, and one inventor may have many patents. The diagram shows the
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`same for other relationships, such as assignment at grant and citations. Fields that a patent may strictly
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`have one of are listed in the Patent entity (with the addition of primary class, shown by arrows pointing
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`away from the Patent entity).
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`3.1.1 Linkages External to Patent Grant from the USPTO
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`I incorporate linkages to two relations provided by the USPTO through Google. The first is maintenance
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`fee events. These are provided as a table indicating patent number, date of event, and type of event (eg,
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`payment of a certain type of fee or refund for various reasons). Also relevant to the analysis, each event
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`contains an indicator for whether the assignee claims small entity status, which affords the inventor a reduced
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`financial burden. In the US, the patent fee schedule is highly back-loaded, as shown in Table 2. Because
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`a relatively small number of patents are renewed to full maturity, this data offers an indication for patents
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`that have issued several years in the past as to how much their owner values them.
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`Table 2: Summary of Current Major Fee Schedule (USD)
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`Type of fee
`Utility issue fee
`Due at 3.5 years
`Due at 7.5 years
`Due at 11.5 years
`
`Standard Amount Amount for Small Entity
`1,770
`885
`1,150
`575
`2,900
`1,450
`4,810
`2,405
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`At the time of grant, the patent examiner places a patent into one of more than 400 technology classi-
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`fications, primarily for the purpose of facilitating future searches for relevant prior art. These classes are
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`further broken down into thousands of sub-classes. The class system frequently changes as new classes are
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`created, merged, or obsoleted. A very recent addition to the USPTO’s bulk data downloads is a file linking
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`each patent to its current classification. These are the technology classes analyzed in this paper. Still, an
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`overwhelming challenge to all researchers working with patent data has been finding meaningful groupings
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`for patents by economically relevant industries, as opposed to by the USPTO’s large number of technology
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`classes.
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`3.2 Litigation Data
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`No branch of the government, including the USPTO, keeps track of patent infringement suits for individual
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`patents. However, the US court system makes documents pertinent to legal cases available online through
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`services such as Public Access to Court Electronic Records (PACER) for a fee of a few cents per page
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`downloaded.
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`Lex Machina is a private firm spun out of a joint research project between Stanford’s law school and com-
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`puter science department called the IP Litigation Clearninghouse, which was designed to bring transparency
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`to IP law. The business of Lex Machina is providing IP litigation data and analytics to businesses. The
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`company does this by crawling court records including those from PACER and district court databases daily.
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`10
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`Alex Bell
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`An Autopsy on Submarine Patents
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`Using natural language processing algorithms, they determine which cases are instances of IP litigation, and
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`in the cases of patent infringement, link the case with the patent being infringed upon (also known as the
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`patent being “asserted”).
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`Although Lex Machina sells this information to businesses, they agreed to contribute to this project a
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`dataset of linkages from patent numbers to legal assertions for all patents filed in 1995.
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`In section 5, I
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`examine how the likelihood of assertion changes for patents filed just before and just after the policy change.
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`3.3 NBER Patent Data Project and Name Matching
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`This paper does not use the NBER database, but it is useful to discuss in terms of work that has been done
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`with similar raw data to what I am using. The work done by the PDP and made public to researchers has
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`been instrumental in speeding the diffusion of this data through the empirical research community. The data
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`provided by the Patent Data Project is outlined in Hall, Jaffe, and Trajtenberg (2001). It contains data
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`primarily on patent citations and assignees.
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`The most significant drawback of this dataset is that it is only current as of 2006. In examining long-
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`pending patents filed around the 1995 discontinuity, the picture would look different if we examined only
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`patents issued by 2006.
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`A tremendous contribution of this dataset is the authors’ attempts to conduct meaningful assignee name
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`disambiguation and matching to Compustat firms. This is not a trivial task for several reasons. Consider a
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`company identified in Compustat as IBM. In addition to filing patents as IBM, patents they file might list
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`as assignee:
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`1. An unabbreviated name, such as International Business Machines
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`2. Some formal legal name, such as IBM, Inc. (or other languages’ variants). This is extremely common.
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`3. A division of the company (eg “IBM R&D”, “IBM Circuits Division”, or “IBM India”). This is also
`extremely common.
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`4. A misspelling of any of the above, perhaps due to data entry error.
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`The architects of the dataset share their name standardization routines on their site. There isn’t much
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`to do about (1). By either removing or standardizing most common suffixes and other elements of firm
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`names, the authors seem to do a good job of mitigating lost matches due to (2). To