Open Access Author Manuscripts in PubMed Central

Of ~1,000,000 articles deposited in PubMed Central from the last 10 years, ~300,000 are marked as "Open Access". Many of these come from "paid open access" programmes, where a fee is paid when the article is published so that it becomes more freely accessible. These schemes include "Springer Open Choice" (15,000 articles), "Elsevier Sponsored Articles" (2,711 articles) and "NPG Open Access" (561 articles).

Of the ~1,000,000 articles in PubMed Central, ~180,000 are marked as "Author Manuscript" - deposited in response to funder mandates, or where the author has retained permission to deposit a pre-print in repositories. However, only 163 of these are marked as "Open Access".

The question - raised by Casey Bergman - is why there is so little overlap: why are author manuscripts not being marked as Open Access in PubMed Central?