The Size of the Public Domain (Without Term Extensions)

Posted on 26 May 2010

We’ve looked at the size of the public domain extensively in earlier posts.

The basic take away from the analysis was the finding that, based on library catalogue data, for books in the UK, approximately 15-20% of work was in the public domain – with public domain work being pretty old (70 years plus, due to the life+70 nature of copyright).

An interesting question to ask then is: how large would the public domain be if copyright had not been extended from its original length of 14 years with (possible) 14 year renewal (14+14) set out in Statute of Anne back in 1710? And how does this compare with how the situation, back when 14+14 was in “full swing”, say, 1795?

Furthermore, what about if copyright today was a simple 15 years – the point estimate for the optimal term of copyright found in paper on this subject? Well here’s the answer:

Today1795 (14+14)Today (14+14)Today (15y)
Total Items3.46m179k3.46m3.46m
No. Public Domain657k140k1.2m2.59m
%tage Public Domain19785275

Number and percentage of public domain works based on various scenarios based on Cambridge University Library catalogue data.

That’s right folks: based on the data available, if copyright had stayed at its Statute of Anne level, 52% of the books available today would in the public domain compared to an actual level of 19%. That’s around 600,000 additional items that would be in the public domain including works like Virginia Woolf’s (d. 1941) the Waves, Salinger’s Catcher in the Rye (pub. 1951) and Marquez’s Chronicle of a Death Foretold (pub. 1981).

For comparison, in 1795 78% of all extant works were in the public domain. A figure which we’d be close to having if copyright was a simple 15 years (in that case the public domain would be a substantial 75%).

To put this in visual terms, what the public domain is missing out as a result of copyright extension is the yellow region in the following figure: those are the set of works that would be public domain under 14+14 but aren’t under current copyright!

PD Stats

The Public Domain of books today (red), under 14+14 (yellow), and published output (black)

Update: I’ve posted the main summary statistics file including per-year counts. I’ve also started a CKAN data package: eupd-data for this EUPD-related data.