Response from Library Leaders to ‘Usage Half-Life’

Open Library Letter on “Journal Usage Half-Life” and Embargo Periods.

We are writing as representatives of research and academic libraries across the country. As such, we represent the majority of the customer base for academic journal subscriptions in the U.S.  We are writing in response to the recent “Journal Usage Half-Life” report, funded by the American Association of Publishers (AAP), which examines the time it takes for a group of articles to reach half their number of downloads across a variety of academic disciplines – the so-called usage half-life. The study concludes that this number varies both within and among research disciplines.

Recently, some in the publishing community have suggested that this “usage half-life” metric should be used by research funders to justify extending the length of embargo restrictions placed on articles reporting the results of publicly funded research beyond the 12 month period recommended in the February 22^nd White House Directive on “Increasing Access to the Results of Federally Funded Research.”  This argument is based on the assumption that research and academic libraries – who buy the vast majority of scholarly publication subscriptions – make decisions on whether to continue subscriptions based on the median number of times each specific journal is downloaded over time.

As representatives of research and academic libraries across the country, we strongly believe it is important to rebut that assumption. While the usage half-life of articles is an interesting data point, it is not used by research or academic libraries in journal subscription cancellation decisions.  Moreover, this argument falsely assumes that journal publications are subscribed to separately, when in fact, in many cases libraries purchase journals as large bundles – especially from commercial journal publishers. Any metric based on false assumptions is destined to draw incorrect conclusions.

This is not the first time that subscription-based publishers have tried—and failed— to show evidence of a link between usage half-life and lost subscription revenue due to planned public access policies.  The U.S. National Institutes of Health has had a required public access policy with a maximum allowed embargo period of 12 months in place for nearly six years. Hundreds of thousands of articles in a wide variety of disciplines (including those that the Davis study indicates have quite long “Usage Half-Lives”) have been made publicly accessible during this time frame, yet no publisher has reported any loss of subscriptions due to this policy.

In fact, we are not aware of any evidence that the viability of any journal is put at risk by public access policies.  A recent (September 2013) review by the UK House of Commons Select Committee on Business, Innovation and Skills noted “the absence of evidence that short embargo periods harm subscription publishers,” and concluded that “there is no available evidence base to indicate that short (or even zero) embargoes cause cancellation of subscriptions.”[1]

The government invests taxpayer dollars in scientific research with the expectation that those results will be diffused and built upon as widely and as quickly as possible to accelerate discovery, speed innovation, and fuel economic growth. While usage half-life reports provide an interesting metric for comparing journal downloads across disciplines, this study fails to provide any evidence that journal subscription rates will decline as a result of public access policies. It should not be used as a rationale for longer embargo periods in implementing the White House Directive, or any other public access policy. 

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