Open access scientific journals: an analysis of the DOAJ catalogue

Introduction. The research aims to analyse the publishers, countries of publication, citation indexes, article processing charges, and their inter-relations, in the journals that make up the Directory of Open Access Journals (DOAJ), a global directory that offers scientific information in immediate and exclusive open access. Method. Bibliographic, quantitative, and inferential study of 9,005 journals in the DOAJ, focusing on publishers, countries of publication, article processing charges, and citation indexes. Analysis. Calculation of absolute and relative frequencies, measurement of central tendency, chi-squared test, and Mann-Whitney U test using the R statistical software (version 3.2.4) with a 95% confidence interval. Results. Brazil is the country with the largest number of titles (10.9%), followed by the United Kingdom, which has a greater number of titles with article processing charges fees averaging US$ 1,474 for those that are DOAJ No Seal and US$ 862 for those that are certified DOAJ Seal. Europe has the greatest number of open access titles (47.6%). The Hindawi Publishing Corporation, Elsevier, De Gruyter Open, BioMed Central, and Springer are the publishers with the greatest number of journals and a higher presence in citation indexes (Journal Citation Reports and SCImago Journal Rank). DOAJ Seal journals are correlated and more likely to have article processing charges fees. Conclusions. In the consolidation of open access journals, commercial publishers and countries with a tradition of scientific publishing continue to gather the majority of journals. Thus, the oligopoly of commercial scientific publishers is maintained.