Does online access promote research in developing countries? Empirical evidence from article-level data

•We examine whether free online access to environmental science journals promotes research in developing countries.•Variation in online access is exogenous at the level of scientific fields within a given institution.•We apply a difference-in-difference-in-differences approach using OLS, IV and Bayesian estimation methods.•We find that free online access to journals increases scientific output by +29.6% (95% C.I. 18.5% to 40.6%).•This adds up to 2.1 additional articles due to the OARE program for an average institution.•In terms of publication input, online access increases the number of references by +8.4% (95% C.I. 5.6% to 11.2%).•It increases the number of references to environmental science articles by +14.5% (95% C.I. 7.5% to 21.5%).