Compliance with open access mandates and its effects on research visibility: the case of the Spanish National Plan of R&D

This paper evaluates the Spanish open access (OA hereafter) mandate and its effects on Spanish research from 2014 to 2019. First, the degree of compliance with the mandate is studied. Then, classification trees and regression models are applied to determine the factors that are correlated with publishing in OA, and the implications of OA types in terms of the impact and visibility of academic articles. Results show that the compliance rate increased by 9% during the studied period, with a prevalence of gold and green OA routes. Moreover, the classification tree points towards the institutions' nature and the research areas as the variables that better explain OA publishing. We argue that the commitment and the institutions’ policies regarding OA, and the different availability of OA journals within research fields influence the decision of publishing in OA. Last, we study how these practices affect research’s visibility and impact. We found that, in general, publishing in OA is beneficial for researchers, especially if they choose the green route. Further research at faculty or departmental level might be helpful to discern the best strategies to encourage open access publishing.