Many universities are encouraging their staff to publish their research in open access journals, or as open access articles in journals that allow this (for a fee). The theory is that open access publications are easier to access, and so are read more often and attract more citations. The number of citations is a key metric for research quality for journal articles, and this flows through into measures of research quality at the institutional level, which contribute to university rankings (e.g. see here for one example). If open access leads to more citations, then encouraging open access publication is a sensible strategy for a university.
However, it relies on a key assumption - that open access articles receive more citations. In a new NBER working paper (ungated version available here), Mark McCabe (Boston University) and Christopher Snyder (Dartmouth College) follow up on their 2014 article published in the journal Economic Inquiry (ungated version here), where they questioned this assumption. The earlier article showed, looking at the level of the journal issue, that open access increased citations only for the highest quality research, but decreased citations for lower quality research.
In the latest work, McCabe and Snyder first outline a theoretical model that could explain the diverging effect of open access status on high-quality and low-quality articles. The theoretical model explains that:
...open access facilitates acquisition of full text of the article. The obvious effect is to garner cites from readers who cannot assess its relevance until after reading the full text. There may be a more subtle effect going in the other direction. Some readers may cite articles that they have not read, based on only superficial information about its title or abstract, perhaps rounding out their reference list by borrowing a handful of references gleaned from other sources. If the cost of acquiring the article’s full text is reduced by a move to open access, the reader may decide to acquire and read it. After reading it, the reader may find the research a poorer match than initially thought and may decide not to cite it. For the lowest-quality content, the only hope of being cited may be “sight unseen” (pun intended). Facilitating access to such articles may end up reducing their citation counts...
A distinctive pattern is predicted for the open-access effect across the quality spectrum: the open-access effect should be increasing in quality, ranging from a definitively negative open-access effect for the worst-quality articles to a definitively positive effect for the best-quality articles.
McCabe and Snyder then go on to test their theory, using the same dataset as their 2014 article, but looking at individual journal articles rather than journal issues. Specifically, their dataset includes 100 journals that publish articles on ecology from 1996 to 2005, with over 230,000 articles and 1.2 million observations. They identify high-quality and low-quality articles based on the number of cites in the first two years after publication, then use the third and subsequent years as the data to test the difference in citation patterns between articles that are available open access, and those that are not. They find that:
...the patterns of the estimates across the quality bins correspond quite closely with those predicted by theory. The open-access effect is roughly monotonic over the quality spectrum. Articles in the lowest-quality bins (receiving zero or one cite in the pre-study period) are harmed by open access; those in the middle experience no significant effect; only those in the top bin with 11 or more cites in the pre-study period experience a benefit from open access. Moving from open access through the journal’s own website to open access through PubMed Central pivots the open-access effect so that it is even more sensitive to quality, resulting in greater losses to low-quality articles and greater gains to high-quality articles. PubMed Central access reduces cites to articles in the zero- or one-cite bins by around 14% while increasing cites to articles in the bin with 11 or more cites by 11%.
So, it appears that publishing open access is not necessarily an optimal strategy for a researcher - this would only be true for those researchers who are confident that a particular article is in the top quintile of research quality. For some researchers this is true often, but by definition it cannot be true often for every researcher (unless they work for Lake Wobegon University). Moreover, for most universities, where the majority of their staff are not publishing in the top quintile of research quality, a policy of open access for all research must certainly lower citation counts, the perceived quality of research, and university rankings that rely on measures of research quality.
[HT: Marginal Revolution]
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