Measuring compliance with a S panish G overnment open access mandate

Open access ( OA ) mandates are policies that require researchers to provide free, unrestricted access to their published research by including it in OA journals (gold OA ) or depositing it in freely available disciplinary or institutional repositories (green OA ). This study measures the degree of compliance with a Spanish government OA mandate 2.5 years after its implementation. A total of 58.4% of articles resulting from publicly funded research had at least one OA copy available 1 year after publication. Among these, 23.8% were in gold OA , 21.8% in green OA and 12.8% in gray OA , i.e., posted on websites and social networks. Most of the green OA articles were in 2 disciplinary repositories: arXiv and P ub M ed C entral. Just 14.4% of the articles resulting from publicly funded research were available in institutional repositories, although more than 90% of the articles in the data set were the result of projects carried out at institutions that have such an archive. There is great potential for growth in green OA , because over two thirds of the articles that were not available as OA were published in journals whose publishers allow a preprint or a postprint copy to be deposited.