"5468 journals that published 4.986.335 papers between 2015 and 2019 were analysed...Our results reveal a subset of journals where a few authors, often members of the editorial board, were responsible for a disproportionate number of publications. The papers by these authors were more likely to be accepted for publication..."
In this context, it's worth noting another study on the influence of social relationships between authors and editors in the peer review process, using PLOS ONE as a case study with over 100,000 articles published from 2007 to 2015. The study found that editors more frequently handle articles co-authored by past collaborators, and these prior relationships are linked to faster review times. https://link.springer.com/article/10.1007/s11192-017-2309-y
