This week Nature published a News piece by Declan Butler with the rather provocative title “PLoS stays afloat with bulk publishing”. Unsurprisingly, this caused a backlash from open-access advocates in general and science bloggers in particular. Jonathan Eisen posted the ironic response “Only Nature could turn the success of PLoS One into a model of failure”. For an overview of the many other responses from the blogosphere see the summary by Coturnix and the long debate on FriendFeed.
The core of the criticism by Declan Butler was directed against the business model of the Public Library of Science (PLoS), in particular that a large part of their total income is produced by “bulk publishing” in the “database” PLoS ONE with only “light” peer review. There is no point in denying that PLoS ONE is a major source of income for PLoS, that it publishes many papers, and that it is not a top-tier journal. Still, it is in my view an unnecessary provocation to refer to a journal from a competitor as a “database” and between the lines suggest that they do not perform proper peer review.
I have nothing against Nature Publishing Group (NPG) – they are in my view one of the more progressive publishers with initiative such as Connotea and Nature Network. However, I find the criticism by Declan Butler somewhat unfair, especially considering that NPG also has a considerable number of lower impact journals in their portfolio in addition to their lineup of Nature journals. To illustrate this point, I looked up the impact factors for all the PLoS and NPG journals that I could find (6 and 68, respectively) and plotted the distributions:
The average impact factors of the two publishers are remarkably similar 9.19 for PLoS and 9.39 for NPG, but the underlying distributions are very different. Notably, the high average impact factor of NPG’s journals is due to a fairly small number of journals with impact factors over 20, which are sufficient to offset the large number of journals with impact factors below 5. Consequently, the median impact factors are 9.03 for PLoS and only 4.88 for NPG.
I want to be the first to point out the caveats of this analysis. First, the analysis above did not take into account that each journal does not publish the same number of papers. However, weighting the journals by number of papers when calculating average impact factors shifts the balance in favor of PLoS (9.79 for PLoS vs. 9.46 for NPG). Second, the journal PLoS ONE does not have an impact factor yet and was thus not included in my analysis. Third, the criticism by Declan Butler was mainly targeting the fact that much of PLoS’ revenue is due to PLoS ONE. However, until NPG chooses to make available detailed financial reports like PLoS does, it is impossible to tell how much of their revenue comes from lower-impact journals.
That being said, the business models of PLoS and NPG do not look all that different based on bibliographic metrics alone.
Full disclosure: I am an associate editor of PLoS Computational Biology.