The public domain is a valuable global asset. A forward looking approach to the use of the public domain would allow the extraction of considerable economic and social value from it. In particular, COMMUNIA asserts that open and public domain approaches can produce economic and social value. Unfortunately, so far this value has been left unattended. In addition, the intellectual property rhetoric has hidden the public costs of extreme propertization of the public. The current paradigm “binds us to a narrow and erroneous viewpoint, in which innovation is central but access is peripheral,” Rufus Pollock has noted.
This imbalance should be redressed. This is far more relevant now, because this disproportion between innovation and access prevents us from taking full advantage of the possibilities offered by the digital age. Digitization and Internet distribution have multiplied the potentialities and opportunities offered by the use of public domain material. On one hand, digitization offers the opportunity to extract economic value out of the public domain by benefiting the public with free or inexpensive cultural resources. On the other hand, digitization may produce immense social value by opening society up to immediate and unlimited access to culture and knowledge.
In addition, the economic and social value of the public domain is enhanced by the mass production capacities of the digital environment. A new peer-based culture of sharing is changing our cultural landscape through the revolutionary technological ability of multiplying references instantaneously and endlessly. Openness and access fuel this new culture of shared production of knowledge. Commodification and enclosure of the public domain threaten its growth and survival.
The next portion this Report is intended to map the value of the public domain. To that end, the Report will briefly discuss sources, size, social and economic value, role, and uses of the public domain in Europe.
As mentioned earlier, to assess the value of the public domain the European Commission has launched a tailor-made project, the Economic and Social Impact of the Public Domain in the Information Society project. The findings of that project shall be of avail in the following analysis. The project, together with its methodology, was presented at the 1st COMMUNIA Conference in Louvain-la-Neuve in 2008 and the 7th COMMUNIA Workshop in Luxembourg. The Public Domain in Europe project pursues the following main goals: estimating the number of works in the public domain in the EU; estimating the economic value of works in the public domain for the next 10-20 years; determining any change in value of works under copyright and once in the public domain; analyzing the current practices for re-use of public domain material held by European cultural institutions; reviewing current available mechanisms for voluntary sharing and assessing their efficiency and impact.
Before delving into the assessment of the value of the public domain, we should start by identifying its sources. A first set of sources of the public domain belongs in what can be termed the structural public domain or the “constitutionally core elements of the public domain.” As part of this core elements, an immediate source of the public domain is represented by those works not deserving of protection because, to use the words of the Public Domain Manifesto,
they fail the test of originality, or are excluded from protection (such as data, facts, ideas, procedures, processes, systems, methods of operation, concepts, principles, or discoveries, regardless of the form in which they are described, explained, illustrated, or embodied in a work, as well as laws and judicial and administrative decisions).
This category partially overlaps with what authors have called “those aspects of copyrighted works that copyright does not protect.” These aspects may be termed as the ontological public domain and are defined by the application of the idea-expression dichotomy, the criteria for protection, either the requirement of originality or substantial investment, and the exhaustion doctrine. The identification of the ontological public domain is left to a dissection test separating protectable from non-protectable elements of a work. The application of this test is often a complex case by case analysis, and, thus, inherently unpredictable. In this unpredictability rests the inevitable indeterminacy of the public domain. COMMUNIA calls for a partial solution to this unpredictability through its policy Recommendation # 4.
Expiration of copyright is a second relevant source of the public domain. Differently than the previous, this category is inherently predictable. Once the temporary right granted to authors is expired, the author’s works enter the public domain. Nonetheless, the incredible complexity of copyright term rules makes it very difficult to determine the copyright status of individual works. This means that one of the biggest obstacles to positively identifying public domain works lies in the cumbersome process of determining the term of copyright protection. To this end promoting the development of efficient public domain calculators will help to counter this further source of indeterminacy of the public domain and thus help to unlock cultural, educational and economic potential of public domain works. Nevertheless, the development of public domain calculator cannot be by any means a general remedy. The complexity of the legal framework, therefore, calls also for a simplification of the rules of copyright term calculation, as COMMUNIA recommends by means of its policy Recommendation # 4.
Depending on special rules of exclusion from copyright protection of official acts within each jurisdiction, public data and official information produced and voluntarily made available by governments or international organizations may be a further source of the public domain. For example, the U.S. law precludes copyright protection for laws and other governmental works. In Europe, though much governmental information and data produced by public authorities might still be copyrighted, the public availability of governmental information and data has been broaden by many ongoing efforts. Most prominently, the Directive 2003/98/EC is intended to encourage the reuse and the commercial exploitation of public sector information. Practical implementation and further efforts toward openness are still sought at the national level, though, as also recommended by COMMUNIA policy Recommendation # 13.
There is, then, other material whose nature as a source of the public domain is more contested. As the Public Domain Manifesto puts it, next to the structural public domain would lie a functional public domain. Structural and functional public domain sources would be distinguished by the circumstance that “in the first case, the openness and freedom of use is premised on the non-[in]existence of copyright, in the second case on the impossibility to exercise and enforce copyright exclusivity.” As per the Public Domain Manifesto, the functional public domain represents “the “breathing space” of our current culture and knowledge” that it is made of “sources that enable individuals to freely interact with copyright protected works.” The Public Domain Manifesto identify the sources of the functional public domain as the “works that are voluntarily shared by their rights holders” and “the users prerogatives created by exceptions and limitations to copyright, fair use and fair dealing.”
Therefore, firstly, contiguous to the structural public domain is a set of privileged uses under copyright exceptions and limitations, fair use, and fair dealing. Public domain and copyright exceptions and limitations, in fact, share the public interest of enhancing access to culture and creativity. In general, copyright exceptions and fair uses are deemed to be only functionally equivalent to public domain material. Nonetheless, a more extreme approach would locate within the public domain any use for which permission is not required.
Secondly, it is debated whether, and to what extent, content distributed under open access models, such as open source software, free software, and creative commons material, can be located within the public domain. Generally, open source software and CC-licensed content are included in a territory adjacent to the public domain. The nature in between copyright all rights reserved and public domain no right reserved is due to the intellectual property rights acting as the very source of authority for the license terms under which this content is freely and openly distributed. However, as noted earlier, open source software, free software, and creative commons content belong to the category of contractually constructed commons and thus share much of the value of public domain content.
As a final note, it is to be observed that the sources of the public domain may vary from jurisdiction to jurisdiction and shift overtime. By way of example, original design of useful articles and unoriginal compilation of facts will be feeding the public domain in the United States but not in Europe. Conversely, business methods and certain biotechnology innovation will serve as a source of the public domain in Europe but not in the United States. This may be an issue when attempting to map the public domain. Drafting national public domain maps for comparative analysis should minimize this difficulty, though.
In order to determine the overall value of the public domain, the first step to undertake is to assess its size. So far only one quantitative study on the size of the public domain is available in Europe. The study was developed within the Public Domain in Europe project by Rufus Pollock, Paul Stepan and Mikko Valimaki. The study was presented by Rufus Pollock at the 7th COMMUNIA Workshop in Luxembourg. The study attempts to estimate the number of items in the public domain across a variety of European countries and different media types. The study focuses only on that part of the structural public domain that is composed by works whose copyright is expired. The results of the study show that
the public domain for books alone consists of hundred[s] of thousands, and sometimes millions, of items, and that, taken as a whole, the European Public Domain must be measured in the millions, or even tens of millions. While a brief perusal of the relevant datasets indicates that much of this material may have only slight value today, nevertheless the scale and diversity of this vast public domain is indicative of significant value, cultural, social and commercial. 
In addition, the study reports a public domain for sound recordings that consists at least of tens of thousands of items. As per films, the study concludes that, since movies are an invention of the nineteenth century, “it is therefore likely that very little film is in the public domain.”
Needless to say, this study is only an initial partial quantitative assessment of the European public domain. Further studies are awaited to come up with more complete and precise data, in particular in the sound recording sector. In addition, any such study should be coupled with the assessment of the remaining part of the structural public domain and the amount of works that are voluntarily shared or dedicated to the public domain.
A quantitative research on a related issue has been carried out in the United States.  Paul David and Jared Rubin examined the impact of US copyright expansion on reducing the size of the public domain. They have tried to quantify the extent of the incursions into the public domain in books that have resulted from legal extensions of U.S. copyright law during the 20th century. David and Rubin made estimates of lower and efficient upper bounds for each of the several statutory changes, measured in terms of the number of copyrighted works that unambiguously will have been returned to the public domain in every year, going forward into the 2020's. The study found that “by 2027, changes in copyright laws over the last half-century will have prevented over 3.5 million books that would otherwise have entered the public domain from doing so.”
The value of the public domain is a complex variable made up of many components. The public domain is a source of value in both economic and social terms. In addition, value can be extracted from the structural and the functional aspects of the public domain. The contribution of the public domain can be assessed in positive or negative terms by estimating the economic and social loss of enclosure and commodification. The positive value of the public domain can be the effect of direct use, indirect use or reuse of public domain works, the application of public domain business models, the market efficiency triggered by a healthy public domain or, again, the democratic function of the public domain. In any event, social and economic value is always very much tangled up in the assessment of the riches of the public domain.
As per the value of a work entering into the public domain or public domain effect, we refer to the concept as described by Rufus Pollock within the framework of the Economic and Social Impact of the Public Domain in the Information Society project.  Firstly, the revenue value is to be distinguished from the social value of the public domain, as the economic utility generated for society. An example may help to differentiate the two concepts. Let us say that after a work enters in the public domain, that work is sold for €5 instead of €10, or may even be downloaded for free online. The social value of the work entering in the public domain, or the “consumer surplus,” will be €5 or €10, if the work is freely accessible. Conversely, if we only looked at the revenue value, we should conclude that the value of the work dropped from €10 to €5 or zero.
In addition, the social value of a work entering in the public domain will also include the deadweight loss of restricting access to a good that it is spared to society. With the term deadweight loss, economic analysis refers to the loss for society consequent to that portion of population that cannot afford to buy the good at a monopolistic price. For that portion of population, society gains the entire value that each consumer puts upon the work. As an example of the value that may be lost due to enclosure of the public domain, recent studies have shown data that suggest that, as to fictional books, copyright extension imposes deadweight losses without any offsetting efficiency gain. The data show that in-print status and in store availability of public domain books are higher or equal to copyrighted books. Instead, the titles in the public domain are significantly less expensive than their copyrighted counterparts.
Finally, the assessment of the value of a work entering in the public domain must also take into account the value of reuse. In the case of monopolies on intellectual productions, innovators and creators will be prevented from developing derivative works or invention from the original. Reducing the public domain or retarding the entrance of a work into the public domain shall deprive the community of the correspondent social value of reuse. Differently than the social value mentioned earlier, the value of reuse is a dynamic value that boosts society both economically and culturally.
Together with the value that may be immediately extracted from the entrance of a work into the public domain, the public domain or a public domain approach to knowledge management may be a source of value on many different levels. Before delving into a more specific account of the social and economic value that can be extracted from the public domain, we note that, in general terms, public domain literature has identified eight values of public domain information and works:
- 1. building blocks for the creation of new knowledge, examples include data, facts, ideas, theories and scientific principle;
- 2. enabling competitive imitation, through for example expired patents and copyright, or publicly disclosed technologies that do not qualify for patient protection;
- 3. enabling follow-on innovation through expired patents and copyrights and leaked trade secrets;
- 4. enabling low cost access to information without the need to locate the owner or negotiate rights clearance and pay royalties, through for example expired copyrighted works or patents, and non-original data compilation;
- 5. access to cultural heritage through information resources such as ancient Greek texts and Mozart’s symphonies;
- 6. promoting education, through the spread of information, ideas and scientific principles;
- 7. promoting public health and safety, through information and scientific principles;
- 8. promoting the democratic process and values, through news, laws, regulation and judicial opinion.
When it comes to value the mentioned benefits of the public domain, however, a quantitative measurement is impossible, at least with the present data and modeling tools. Nonetheless, some quantitative conclusions on the value of the public domain can be inferred by examining few examples of public domain approaches to knowledge production. In general, these examples show the role and the value of the digital public domain in allowing new business models to emerge.
In the case of file sharing, for example, few studies have found significant benefits of free access. One U.S. study has found that public domain type access to music would entail a net gain for society of US$ 45 per person. In addition, seminal studies have found that the impact of peer to peer file sharing on sales does not seem that relevant. Furthermore, data on the supply of new works seem to support the argument that the advent of file sharing did not discourage creators and creativity at large. In fact, the impact of file sharing on creators may be positive due to the increase of the demand for complements to protected works, such as concerts, special editions, or merchandising.
The value of few other examples of public domain models, as singled out by Rufus Pollock’s study, can be more immediately appreciated. Open source software is a quintessential example of the value of an open approach to the production of information goods. The Internet and the World Wide Web are further examples of the great wealth that can be built upon public domain material. These technologies were non-proprietary, and openness was the key to their revolutionary success. Again, online search engines, such as Google, produce relevant social benefit through their service and generate very large revenue by copying “open” information on the web. Oddly enough a strict enforcement of copyright law would bring to a halt the web as it is known today.
Finally, several studies have highlighted that a public domain approach to weather, geographical data, and public sector information in general, may yield a substantial long-run value for Europe, running into the tens of billions or hundreds of billions of euros. The benefit of access to and re-use of public sector information has been widely investigated during the COMMUNIA proceedings among others by Professor Paul Uhlir, distinguished member of the COMMUNIA Advisory Committee. In particular, the 5th COMMUNIA Workshop, co-organized by the Open Knowledge Foundation and the London School of Economics, focused on Accessing, Using and Reusing Public Sector Content and Data.
The value of privileged and fair use of copyrighted material is also to be taken into account when assessing the overall value of the public domain. Privileged and fair uses of copyrighted material are an integral part of the functional public domain. A recent, and so far isolated, study compiled data from 2002 to 2006 to show the contributions to the U.S. economy of companies benefitting from fair use and copyright exceptions. Fair use enhanced industries include manufactures of consumer devices allowing for individual copying of protected content, educational institutions, software developers, and internet search and web hosting providers. The study have found that “the fair use economy in 2006 accounted for $4.5 trillion in revenues and $2.2 trillion in value added, roughly one-sixth of total U.S. GDP. It employed more than 17 million people and supported a payroll of $1.2 trillion. It generated $194 billion in exports and rapid productivity growth.” The study showed that industries based on or benefitting from fair use exceeded GDP, employment, productivity, and export growth of the overall economy. Further, the study reveals that fair use industries have grown dramatically within the past twenty years, since the advent of the Internet and the digital information revolution. These data may help to make a very relevant finding: in the digital environment, open and public domain business models may spur growth at a faster pace than proprietary traditional business models. In addition, the study shows as many of the industry compartments that may be included in the category of copyright-based industry are in fact benefitting from privileged and fair uses of protected materials as well. Those benefits may be, in fact, a more relevant contribution to our economic growth than the benefits coming from the exploitation of proprietary business models, as the study points out. These findings, therefore, should play a central role in directing the European policy strategies.
Promoting fair use and the functional public domain, thus related fair use industry, may have also a considerable added value for Europe. When contrasted with the United States case-by-case fair use model, the European list of predefined limitations and exceptions may be a vantage point for fair use industries in Europe. Fair use decisions are inherently complex and unpredictable in the United States. Fair use has been declined by the United States Court of Appeals of the 2nd Circuit as “the most troublesome doctrine in the whole of copyright.” As a consequence of the inherent unpredictability of fair use in the United States, transaction costs will be higher, legal positions will be uncertain, and commercial endeavours will be chronically open to legal challenge. Europe should maximize the advantages that our legal framework offers to industries based on fair use. The enhanced legal certainty and lower transaction costs of the European legal framework will make that sector flourish in Europe and will boost the international investments. If compared with the United States market, the European Internal Market may become an heaven for fair use industries. However, to that end, Europe needs to advance harmonization of exceptions and limitations across national jurisdictions and introduce an open fair dealing provision to close any loopholes that predefined exceptions and limitations may have, as sought by COMMUNIA policy recommendation # 3.
Further, the public domain plays a relevant role in terms of market efficiency. From an economic standpoint, a market with a shrinking public domain would be especially inefficient. Nobel laureate Joseph Stiglitz stressed this point by noting that
[i]t is imperative to understand the ways in which the production and distribution of knowledge differs from that of goods like steel and cars. [ . . . ]. The fact that knowledge is, in central ways, a public good and that there are important externalities means that exclusive or excessive reliance on the market may not result in economic efficiency.
Restricting access to information would increase the inefficiency of the market because perfect information makes the perfect market. A market that commodifies information excessively will be less efficient in allocating resources in our society since key information to facilitate that allocation will be more difficult to find. In addition, by raising the costs of information, we will undermine creativity since the building blocks of future creations will be inaccessible to a portion of our society.
Finally, as we will discuss in greater detail later, the public domain is an engine of democratization by ensuring a proper access to information for EU citizens regardless of the market power of the players. The value of the public domain as a building block of our capacity of free expression has been immensely enhanced by the ubiquity of the interconnected society and the power of propagation of digitization. Technological advancement makes the public domain the perfect democratic forum.
Practice is often more explanatory than theory. A few examples may help to grasp the value of the “public domain effect,” the entrance of a work in the public domain, and other social and economic value that can be extracted from the public domain.
In 2010, the works of Sigmund Freud entered the public domain in Italy. This event propelled the publication of 36 works of Freud in the first 9 months of 2010 by 10 publishers. This is an astonishing figure if compared with the previous years. In the preceding 10 years, from 1999 to 2009, only 16 works of Freud were published in Italy. In the Czech Republic, works by Karel Čapek reached 39 new editions when the author entered the public domain in 2009. Previously, the corresponding number was between 4 and 10 new editions per year. In the examples given, in fact, decreasing marginal costs of production should be taken into consideration to assess the overall net value for society. However, the capacity of the public domain effect to propel revived interest in works of authorship may outweigh any other considerations. It is worth noting that one of the effects of works falling into the public domain may be to stimulate critical editions as a way to package unprotectable underlying works in a protectable form.
2007 saw the 70th anniversary from the death of Louis Vierne, a renowned French organist and composer, and the end of the copyright protection of his works. Upon expiration of Vierne’s copyright, two German publishers issued new editions of Vierne's opera omnia. These new editions finally corrected many mistakes and inaccuracies included in the original scores. Louis Vierne was born nearly blind due to congenital cataracts, and such mistakes were likely due to Vierne's hesitating writing. Up to the expiration Vierne’s copyright, none of its publishers tried to correct the mistakes, because the copyright laws prevented them from editing the original works whatsoever. Only the full release in the public domain enabled a new publisher, Bärenreiter, to finally provide anybody in the world with a correct, elegant and appropriate collection of such great compositions.
Again, an anecdote about the effect of a work suddenly falling into the public domain is enlightening to grasp the value of the public domain. The film “It’s a Wonderful Life,” directed by Frank Capra and starring Jimmy Stewart, fell into the public domain in 1974 after the copyright holder failed to renew it. The film had been largely ignored since its original release. However, in 1975 a TV station discovered that the movie was freely available and ran it during Christmas, because its climax comes on Christmas Eve. Within a few years “It’s a Wonderful Life” was being shown on televisions stations across the United States at Christmas. The success was terrific. Watching the movie at Christmas time became a cultural tradition in the United States, and references to the movie became commonplace as well.
Finally, a passage in English cultural history may further express the value of the public domain, as persuasively argued by William St. Clair. The persistent and strong impact of the poets and novelists of the English Romantic period upon the reading public of the Victorian age, may be the consequence of the conjunctures of events affecting the economics of the printing and publishing business in Britain. In particular, that strong impact may be the result of the public domain effect on the works of the English Romantic authors. The works of English Romantic poets and novelists – Scott, Byron, Coleridge, Keats, Shelley, Campbell, Southey, and Wordsworth – appeared during the transient interval of short copyright protection granted under the judicial implementation of the statutory copyright prescribed by the Statue of Anne. That interval spanned from 1774 to 1841. Meanwhile, the application of stereotype printing technology propelled mass reprinting of inexpensive titles that could be kept "in print" for an unprecedented length of time. After 1841, the span of copyright protection in Britain was lengthened to two and then to three generations. As a result, the English Romantic literature prevailed as a canon in the Victorian age (1837-1901) after emerging from copyright to reach a greatly enlarged public in innumerable cheap editions within only a generation of their having been written. The literature published after 1841 did not reach the same enlarged audience within such a short term, therefore giving way to the endurance of the Romantic literature among the public.
 Pollock, The Value of the Public Domain, supra note 82 4.
 See Mark Isherwood, Rightscom Ltd, European Commission project: Economic and Social Impact of the Public Domain. Introduction to Methodology, paper presented at the 1st COMMUNIA Conference (June 30, 2008).
 See Mark Isherwood, Economic and Social Impact of the Public Domain in the Information Society, presentation delivered at the 7th COMMUNIA Workshop (February 1, 2010).
 Samuelson, Mapping the Digital Public Domain, supra note 63, at 150.
 The Public Domain Manifesto, supra note 79.
 Litman, The Public Domain, supra note 81, at 968.
 See Dusollier, Scoping Study On Copyright and the Public Domain, supra note 76, at 22-25; Lucie Guibault, Evaluating Directive 2001/29/EC in the light of the Digital Public Domain, paper presented at the 1st COMMUNIA Conference (July 1, 2008), at 3 [hereinafter Guibault, Evaluating Directive 2001/29/EC].
 See United Nations Educational, Scientific and Cultural Organization [UNESCO], Gen. Conf., 32nd Session, Recommendation concerning the Promotion and Use of Multilingualism and Universal Access to Cyberspace, at 7 (November 21, 2003) available at http://portal.unesco.org/ci/en/files/13475/10697584791Recommendation-Eng.pdf/ Recommendation-Eng.pdf (including those data in the definition of public domain information); see also Antony Taubman, The Public Domain and International Intellectual Property Law Treaties, in Intellectual Property: The Many Faces of the Public Domain (Charlotte Waelde and Hector L. MacQueen eds., Edward Elgar, 2007).
 See 17 U.S.C. §105 (2006).
 See Council Directive 2003/98/EC on the reuse of public sector Information, 2003 O.J. (L 345) 90 (November 17, 2003) [hereinafter Directive 2003/98/EC or PSI Directive].
 See Guibault, Evaluating Directive 2001/29/EC, supra note 158, at 3-4.
 Dusollier, Scoping Study On Copyright and the Public Domain, supra note 76, at 10.
 See Public Domain Manifesto, supra note 79, at 3.
 See Dusollier, Scoping Study On Copyright and the Public Domain, supra note 76, at 9.
 See Deazley, Rethinking Copyright, supra note 64, at 107 (stating that “if the institution of copyright necessitates permission before use, then the public domain allows for use without the need for permission”); Benkler, Free as the Air to Common Use, supra note 83, at 362-363 (adding to the traditional concept of the public domain the range of privileged uses that are “easy cases”, therefore excluding fair use instances that involve complicated factual inquiries); Valérie-Laure Benabou and Sevérine Dusollier, Draw Me a Public Domain, in Copyright Law: A Handbook of Contemporary Research 167 (Paul Torremans ed., Edgar Elgar 2007) [hereinafter Benabou and Dusollier, Draw Me a Public Domain]; see also The Public Domain Manifesto, supra note 79, at 3 (“The user prerogatives created by exceptions and limitations to copyright, fair use and fair dealing . . . are an integral part of the Public Domain”)
 See Samuelson, Mapping the Digital Public Domain, supra note 63, at 151.
 See Samuelson Pamela, Enriching Discourse on Public Domain, 55 Duke L. J. 101, 124 (2006).
 See Pamela Samuelson, Challenges in Mapping the Public Domain, in The Future of the Public Domain: Identifying the Commons In Information Law 12 (Lucie Guibault and P. Bernt Hugenholtz eds., Kluwer Law International 2006) [hereinafter Samuelson, Challenges in Mapping the Public Domain] (considering and rebutting criticisms of the public domain map).
 Rufus Pollock, The Size and Value of the Public Domain, presentation delivered at the 7th COMMUNIA Workshop (February 1, 2010).
 See Rufus Pollock, Paul Stepan, and Mikko Valimaki, The Size of the Public Domain 20 (Rightscom, Draft, July 8, 2009).
 See Paul A. David and Jared Rubin, Restricting Access to Books on the Internet: Some Unanticipated Effects of U.S. Copyright Legislation, 5 Rev. Econ. Res. Copyright Issues 23 (2008), available at http://papers.ssrn.com/sol3/ papers.cf m?abstract_id=1260527 [hereinafter David and Rubin, Restricting Access to Books on the Internet]; see also Copyright Review Management System, http://www.lib.umich.edu/copyright-review-management-system (a project of the University of Michigan Library to increase the reliability of copyright status determination of books published in the United States from 1923 to 1963).
 David and Rubin, Restricting Access to Books on the Internet, supra note 174, at 46.
 Pollock, The Value of the Public Domain, supra note 82, at 5.
 See Paul J. Heald, Property Rights and the Efficient Exploitation of Copyrighted Works: An Empirical Analysis of Public Domain and Copyrighted Fiction Best Sellers, in New Directions in Copyright Law: Volume 6 75, 78-91 (Fiona Macmillan ed., Edward Elgar Publishing 2007)[hereinafter Heald, Property Rights and the Efficient Exploitation of Copyrighted Works].
 See Samuelson, Challenges in Mapping the Public Domain, supra note 170, at 22.
 See Pollock, The Value of the Public Domain, supra note 82, at 8.
 See Rafael Rob and Joel Waldfogel, Piracy on the High C's: Music Downloading, Sales Displacement, and Social Welfare in a Sample of College Students, 49 J. L. & Econ. 29 (2006), available at www.nber.org/papers/w10874.
 See, e.g., Felix Oberholzer-Gee and Koleman Strumpf, File-Sharing and Copyright, 10 Innovation Policy and the Economy 19, 34-38 (2010), available at http://www.hbs.edu/research/pdf/09-132.pdf [hereinafter Oberholzer and Koleman, File Sharing and Copyright]; Felix Oberholzer-Gee and Koleman Strumpf, The Effect Of File Sharing On Record Sales: An Empirical Analysis 115 J. Pol. Econ. 1 (2004), available at http://www.unc.edu/~cigar/papers/FileSharing_March2004.pdf; Fabrice LeGuel and Fabrice Rochelandet, P2P Music-Sharing Networks: Why the Legal Fight Against Copiers May be Inefficient? (Social Science Research Network Working Paper Series, 2005), available at http://ssrn.com/abstract=810124 (using a unique dataset collected from more than 2,500 French households); but, e.g., Liebowitz Stan, How Reliable is the Oberholzer-Gee and Strumpf Paper on File-Sharing? (University of Texas at Dallas, Working Paper, August 2007), available at http://copyrightalliance.net/files/ssrn-id1014399.pdf; Liebowitz Stan, File Sharing: Creative Destruction or Just Plain Destruction?, 49 J. L. & Econ. 1 (2006).
 See Oberholzer and Koleman, File Sharing and Copyright, supra note 181, at 46-49.
 See Pollock, The Value of the Public Domain, supra note 82, at 11-13.
 Id., at 14; Pira International Ltd et al, Commercial Exploitation of Europe’s Public Sector Information (October 30, 2000) (report prepared European Commission, Information Society DG), available at http://ec.europa.eu/ information_society/policy/psi/docs/pdfs/pira_study/commercial_final_report.pdf; Richard E. W. Pettifer, Towards a Stronger European Market in Applied Meteorology, 15 Meteorological Applications 305 (2008), available at http://www.interscience.wiley.com/journal/118677468/abstract; see also Peter Weiss, U.S. National Weather Service, Borders in Cyberspace: Conflicting Government Information Policies and their Economic Impact (February 2002) available at http://www.nws.noaa.gov/sp/Borders_report.pdf.
 See Paul Uhlir, Measuring the Economic and Social Benefits and Costs of Public Sector Information Online: a Review of the Literature and Future, presentation delivered at the 1st COMMUNIA Conference, Louvain-la Neuve, Belgium (June 30, 2010).
 See Thomas Rogers, Andrew Szamosszegi, and Peter Jaszi, Fair Use in the U.S. Economy: Economic Contribution of Industries Relying on Fair Use (September 2007) (study prepared for the Computer & Communications Industry Association [CCIA]).
 Id., at 7.
 See World Intellectual Property Organization [WIPO], Guide on Surveying the Economic Contribution of the Copyright-Based Industries (2003), available at http://www.wipo.int/copyright/en/publications/pdf/copyright_pub_ 893.pdf; Stephen E. Siwek, Copyright Industries in the U.S. Economy: The 2003-2007 Report (July 2009) (study prepared for the International Intellectual Property Alliance [IIPA], available at http://www.iipa.com/pdf/IIPASiwekReport 2003-07.pdf.
 Dellar v. Samuel Goldwyn, Inc., 104 F.2d 661, 662 (2d Cir. 1939) (per curiam).
 Joseph E. Stiglitz, Public Policy for a Knowledge Economy 25 (World Bank Department for Trade and Industry and Center for Economic Policy Research 1999), available at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1 23.9173&rep=rep1&type=pdf.
 See Sanford J. Grossman and Joseph E. Stiglitz, On the Impossibility of Informationally Efficient Markets, 70 Am. Econ. Rev. 393 (1980).
 Boyle, The Public Domain, supra note 91, at 39-41
 See e-mail from Lukas Gruber, firstname.lastname@example.org, to email@example.com (September 24, 2010, 13:58:00 CEST), available at https://lists.communia-project.eu/cgi-bin/mailman/private/ communia-members.
 See John Sutherland, The Great Copyright Disaster, 17 London Rev. of Books 3-4 (1995).
 See Massimo Nosetti, Il Maestro dell’Organo fuori dal Copyright, in Il Giornale della Musica, November 2008, 38.
 See David A. Paul and Jared Rubin, How many Scanned Books on the Web 6-7 (SIEPER Policy Briefs, December, 2008), available at http://www.stanford.edu/group/siepr/cgi-bin/siepr/?q=system/files/shared/pubs/ papers/briefs/ policybrief_dec08.pdf
 William St. Clair, The Reading Nation in the Romantic Period 20-23 (Cambridge University Press 2004).