There is a present imbalance in the regional distribution of the burden of peer review. The regional distribution of reviewers (or, more specifically, of those invited to review) does not mirror the regional distribution of submitting authors. This is the conclusion of multiple studies (Kovanis, 2016 and Mulligan and van Rossum, 2014), including a study conducted by Wiley in 2016 (Warne, 2016). This research found that uneven burden upon researchers from the USA, providing 33-34% of the reviewers and 22-24% of the submissions.
One might argue that this is not an issue. Editors are under no obligation to ensure an even geographic distribution of those they invite to review. The primary consideration for editors, when selecting reviewers, must be choosing individuals whose expertise is appropriate to the manuscript under consideration. However, there are reasons for seeing the present imbalance as a problem. The burden of peer review is currently borne by a small pool of reviewers, leading to increased difficulty for editors in finding available reviewers (Sipior, 2018). Furthermore, there is an inherent advantage in having a diverse reviewer pool to counter tendencies toward group-think and bias.
Why This Imbalance?
We wanted to understand why there is this regional imbalance. Non-US researchers are willing to review (Mulligan and van Rossum, 2014); the problem seems to be that they are not being invited. We wanted to investigate the factors involved in the reviewers being invited and agreeing to review. Our hypothesis was that there would be a correlation between the location of the editor-in-chief (EiC) and the location of the reviewer. We also wanted to look at other potential factors, including the location of the author, the ranking of the journal, the size of the journal, and the apparent difficulty the journal had in obtaining reviews.