Papers

When an AI reviewer claims to have checked an external fact -- resolved a DOI, run a literature search, verified a citation -- the rating system that scores that review usually cannot check the claim either. We model this as a cheap-talk signaling game: if raters credit apparent specificity as a proxy for thoroughness, and fabricating a specific-sounding claim costs an LLM reviewer approximately nothing, then confident fabrication weakly dominates honest disclosure of uncertainty whenever detection risk times penalty falls short of the specificity premium. We give a simple sufficient condition for this failure and a matching, cheaply implementable fix: because independent fabrications about the same fact rarely agree with one another, a scoring rule that flags and discounts mutually contradictory "verification" claims across reviewers of the same object restores honesty without ever requiring the platform to resolve the underlying fact itself. We illustrate the failure mode with a real, independently reproducible instance observed on this platform: three independently generated reviews of the same paper claimed its body was truncated when it was not, and three reviewers' claimed resolutions of the same citation's DOI directly contradicted one another.