A major threat to the peer-review systems of computer science conferences is
the existence of "collusion rings" between reviewers. In such collusion rings,
reviewers who have also submitted their own papers to the conference work
together to manipulate the conference's paper assignment, with the aim of being
assigned to review each other's papers. The most straightforward way that
colluding reviewers can manipulate the paper assignment is by indicating their
interest in each other's papers through strategic paper bidding. One potential
approach to solve this important problem would be to detect the colluding
reviewers from their manipulated bids, after which the conference can take
appropriate action. While prior work has has developed effective techniques to
detect other kinds of fraud, no research has yet established that detecting
collusion rings is even possible. In this work, we tackle the question of
whether it is feasible to detect collusion rings from the paper bidding. To
answer this question, we conduct empirical analysis of two realistic conference
bidding datasets, including evaluations of existing algorithms for fraud
detection in other applications. We find that collusion rings can achieve
considerable success at manipulating the paper assignment while remaining
hidden from detection: for example, in one dataset, undetected colluders are
able to achieve assignment to up to 30% of the papers authored by other
colluders. In addition, when 10 colluders bid on all of each other's papers, no
detection algorithm outputs a group of reviewers with more than 31% overlap
with the true colluders. These results suggest that collusion cannot be
effectively detected from the bidding, demonstrating the need to develop more
complex detection algorithms that leverage additional metadata.

从论文投标中检测串通可以取得显著成功并保持隐藏，需要开发更复杂的检测算法利用额外的元数据。

从论文投标中检测审稿人与作者串通的共谋环

On the Detection of Reviewer-Author Collusion Rings From Paper Bidding

A recent report of Littmann [Commun. ACM '21] outlines the existence and the
fatal impact of collusion rings in academic peer reviewing. We introduce and
analyze the problem Cycle-Free Reviewing that aims at finding a review
assignment without the following kind of collusion ring: A sequence of
reviewers each reviewing a paper authored by the next reviewer in the sequence
(with the last reviewer reviewing a paper of the first), thus creating a review
cycle where each reviewer gives favorable reviews. As a result, all papers in
that cycle have a high chance of acceptance independent of their respective
scientific merit.
We observe that review assignments computed using a standard Linear
Programming approach typically admit many short review cycles. On the negative
side, we show that Cycle-Free Reviewing is NP-hard in various restricted cases
(i.e., when every author is qualified to review all papers and one wants to
prevent that authors review each other's or their own papers or when every
author has only one paper and is only qualified to review few papers). On the
positive side, among others, we show that, in some realistic settings, an
assignment without any review cycles of small length always exists. This result
also gives rise to an efficient heuristic for computing (weighted) cycle-free
review assignments, which we show to be of excellent quality in practice.

本文旨在解决学术同行评审中的合谋环问题，引入 Cycle-Free Reviewing 概念，分析其难点，提出并验证线性规划方案的短评检测存在问题，最后提出了一种高效的计算赋权的无环评审分配的启发式方法，该方法在实践中具有良好的质量。