1 Introduction
Peer review is the cornerstone of quality control of academic publishing. However, the daunting task of
selecting appropriate reviewers [1, 2] relies in identifying at least two scholars, free of conflict of interest, who
have: 1) the necessary expertise to judge the quality and perceived impact; and 2) the willingness to perform
the work pro bono. On account of this, it is ever more common that journals request, and often require, authors
to suggest candidate reviewers. That is, provide names and contact information of scholars the authors deem
qualified to review.
It is natural to imagine, at first glance, that this incentivizes authors to submit “friendly” names, implying
suggesting reviewers that they have reason to believe would be favorably inclined toward them. The fear of such
peer review manipulation is potentiated by reports that author-suggested reviewers are more likely to recommend
acceptance [3–10]. However, some of these same studies mention that the quality of reports of author-suggested
reviewers does not differ from the ones of editor-suggested reviewers [3–5, 8, 9]. It is also reported that the
difference in suggesting acceptance by author-suggested and editor-suggested reviewers is not significant when
comparing reports of the same submission [7] nor it is observed to have an effect in the article’s acceptance [3,7]
and this discrepancy can even vanish entirely in some fields [11].
The question then naturally arises: can a scientist infer from their personal history of submissions which
reviewers are likely to bias the decision in their favor? In what follows, we present an optimistic agent-based
model that surely underestimates the number of submissions required to ascertain the friendliness of the reviewer
with high confidence. What we find is that, due to multiple sources of uncertainty (e.g., lack of knowledge as
to which reviewer the editor selects), such an effort would require a number of submissions vastly exceeding
the research output of all but the most productive scientists. That is, hundreds and sometimes thousands of
submissions.
As neither a manuscript’s submission history, reviewers selected by the editor, nor suggested reviewers by
the authors are publicly available, we adapt agent-based simulation models [12–14], already used in generating
simulated peer review data [14], and develop an inference strategy on this model’s output to ask whether we
can uncover favorably biased reviewers. This fits into a larger effort to quantitatively study the dynamics of
scientific interactions [15–18].
As we initially simulate the data, we intentionally make assumptions using agent-based models that would
result in easy classification in order to obtain a lower bound on the number of submissions required to confidently
classify reviewers. These assumptions read as follows:
i) For each submission, the author will always suggest a small number of reviewers (three, in our simulation)
from a fixed and small (ten elements, in our simulation) pool of names.
ii) The editor will always select one of the reviewers suggested by the authors.
iii) The “friendliness” of any given reviewer remains the same for all subsequent submissions.
iv) Submissions from the same author all have the same overall quality.
Shortly we will lift the assumptions of this “cynical model” and introduce a “quality factor model” or simply,
quality model. In particular, we will lift assumption iv). As we will see, lifting assumptions will only raise, often
precipitously, the already unfeasibly high lower bound on the number of submissions required to confidently
classify reviewers and leverage this information to bias reports in their favor.
2 Methods
In order to set a lower bound on the number of submissions required to confidently classify reviewers, the
present study focuses on a simplified peer review process characterized by three types of agents: the author(s),
the editor, and the reviewers. Each submission is reviewed according to the following steps:
1) During submission, the author will send to the editor a list of suggested reviewers, S. The suggested
reviewers are chosen from a larger set of possible reviewers R— such that Sis a subset of R.
2) The editor will select one reviewer, namely r1, from Srandomly with uniform probability.
3) The editor will also select a second reviewer, r2, from a pool of reviewers considerably larger than Rand
representative of the scientific community.
4) The reviewers will write single blind reports, either overall positive or negative, and the author will have
access to the number of positive reviews a.
A diagram of this idealized process is presented in Fig. 1.
In the spirit of identifying a lower bound on submissions, we make the dramatic assumption that r1either
belongs to friend or rival class while r2is otherwise neutral. Later we will devise a Bayesian inference strategy
to achieve suggested reviewer (r1) classification.
2