Lack of peer reviewer diversity advantages scientists from wealthier countries

Authors from low- and middle-income countries often have lower acceptance rates in academicjournals, leading to their ideas receiving less attention. One factor hypothesized to affectacceptance rates is the limited geographical diversity of peer reviewers. If reviewers favorsubmissions from their own country and authors from certain countries are disproportionatelyreviewed by same-country reviewers, this creates a “geographical representation bias.” Usingadministrative data from the Institute of Physics Publishing (IOP), encompassing metadata on204,718 submissions to 60 English-language journals from January 2018 to December 2022, wefind evidence of this bias even after controlling for manuscript quality. An exploratory analysisexploiting a policy that resulted in quasi-random anonymization of some submissions shows thathiding authors’ identities does not significantly reduce country-level homophily. The findingssupport the need for sustained efforts at diversifying reviewer pools.