Google Books Ngram Viewer is a fantastic tool showing how certain phrases have occurred in a corpus of books over a selected period of time. Recently, fellow bloggers over at orgtheory have played around with this tool (see, for example, “market – science- religion“).

Working on the issue of the digital public domain during my stay at the WZB, I was curious to compare the mentions of “public domain” and “intellectual property”, which are depicted in the graph below:

The resulting graph is pretty interesting. First, I did not know that the term “intellectual property” was virtually non-existant at all prior to 1980. This is remarkable since the negotiations that in the end led to the WTO’s agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) had started in the early 1980s. Again, we can observe a shifting baseline effect (see “Shifting Baseline in Assessing Copyright Regulation?“): today the concept of “intellectual property” has become completely taken for granted, while 30 years ago even the phrase hadn’t been used.

Second, the rising interest in intellectual property is accompanied by a rising interest in its counterpart, the public domain. As intellectual property becomes more important so does the public domain.

Third, there is a quite sudden change in the overall trend for both phrases somewhere around 2004. Of course, I can only speculate about the reasons for that. Maybe the special issue in Law & Contemporary Problems on “The Public Domain“, edited by James Boyle and published in 2003, had some impact. Even more so, the increasingly widespread diffusion of Creative Commons licenses launched in 2002 might have contributed to a growing interest into the public domain. This does not, however, explain why mentions of intellectual property have started to decrease at about the same time, given the fact that public domain is regularly defined in demarcation to intellectual property.