The Public Domain Does Not Increase Book Sales – Copyright Does

One of the great “truisms” of the Electronic Frontier Foundation, Public Knowledge and other anticopyright groups is that copyright is somehow this incredible drag on the publication and availability of works. And the remedy for this is to push works into the public domain as quickly as possible. But yet, like so many other “truisims” pushed forward by these folks, once you dig into the reality of the situation, the assertion is simply not true at all.

The proof lies in a recently released study by Professor Stan J. Liebowitz of the University of Texas School of Management. 1 Titled “Have We Misunderstood Copyrights Consequences,” it finds that books under copyright protection outsell books of the same vintage which are in the public domain by a ratio of almost 4 to 1. 2

To come to this conclusion, the study examined the actual sales of books in four successive time periods of four years each (2004, 2008, 2012, 2016). The books tracked were the top 10 bestsellers in two equal 27 year time periods: 1895-1922 and 1923-1950. 3 The pre-1923 titles were all in the public domain. The post-1923 titles were all protected by copyright. This resulted in 108 public domain titles to compare against 110 copyrighted titles. 4

The difference maker here is that the study used actual sales numbers as reported by BookScan, which tracks copies sold by both online and offline sellers. 5 Previous studies had used “Books in Print” (BiP) to support their findings. That is a fatal flaw, as the study points out, due to “on demand” publishers who may offer a book for sale, but do not actually print one until it is ordered.

“This is not a merely hypothetical concern: 480 out of the 774 BiP listed editions… failed to sell any copies in 2004 and 311 of these failed to sell any units in the full 13 years of my data.” 6

Once the numbers are crunched using actual sales over potential sales, which as the study shows may never happen at all, the results are striking:

“[T]he average copyrighted title sells almost 4 times as many copies as the average public domain title, and the median [copyrighted] title sells more than 23 times as many units as the median [public domain] title.” 7

This is true even though the copyrighted titles usually carry a higher retail price.

“It is natural to suspect that publishers of the most successful copyrighted vintage titles are taking advantage of their position as sole sellers of popular copyrighted titles to charge these higher prices. But if that were all that was going on, then [copyrighted] titles should not outsell successful [public domain] titles the way that they do…[t]hus an explanation more consistent with the facts…would be that some or all of the revenues from the higher prices for leading [copyrighted] titles, in addition to paying royalties [N.B. which public domain publishers do not pay] would seem likely go to producer activities that help sell these better selling editions.” 8

But wouldn’t more recent titles always sell better than older ones? This theory really doesn’t work since the majority of any book sales occur within two years of first publication. Why this would remain true decades later remains hard to explain. 9 It also assumes that an author in 1922 would have any incentive to delay publication until after 1923, since the author would have no inkling that copyrights would be extended any further. Yet, the study looks at this question by reducing the spread by chopping off an equal number of years from either end of the spectrum, thus comparing books written in a timeline more closely together.

“The sales advantage for [copyrighted] titles is statistically significant for all ranges more than 9 years on each side of the cutoff but also significant …when there are only 5 to six years on each side of the cutoff and is always at least of borderline significance when there are more than 2 year on each side of the cutoff.” 10

So, there you have it. The public domain does make a book potentially more widely available than before. But this does not mean that these books actually sell many copies, or as the study points out, sometimes none at all. Why should a publisher put the time and effort into printing and promoting a book that could have seven different competitors in a matter of days. Where is the great public benefit?

Yet, it is the copyrighted book which sells better, despite being more expensive. Perhaps this is due to the fact that the publisher has greater incentive to make the book available, perhaps in more attractive editions, and to promote the book, since they are protected by copyright. This is the post-creation investment that continued copyright protection encourages.

“The public domain’s disadvantage in this case would simply be another example of the tragedy of the commons, where the lack of property rights for public domain works fails to provide efficient incentives for sales-promoting investment, leading to inefficiency.” 11

“The large positive impact of copyright on sales raises the possibility that the impact of copyright on the consumption of already created works might be positive. If this were the case, however, then the traditional welfare analysis of copyright would be stood on its head. The incentive/access relationship would no longer be a tradeoff since copyright would be socially beneficial on both sides of the ‘balance’…” 12

“But that is not all. The criticisms of retroactive copyright extensions…would also be incorrect. Similarly the supposed benefit to society from allowing already created works to fall into the public domain, which has been taken for granted for so many, would also be incorrect.” 13

And there you have it.


  1. Have We Misunderstood Copyright’s Consequences?
  2. Id. at 14
  3. Id. at 8
  4. Id. at 15
  5. Id. at 9
  6. Id. at 8
  7. 14
  8. 28
  9. Id. at 18
  10. Id. at 21
  11. Id. at 3
  12. Id. at 31
  13. Id.

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