Haustein, Bowman & Costas's taxonomy files authority-based citation under the persuasion pole, not the Matthew-effect pole, though the two behaviors are indistinguishable by content

citation-theorymatthew-effectlegitimationpopularitypersuasion-hypothesisbibliometrics

Haustein, Bowman & Costas (2016) enumerate "persuasion hypothesis" and "Matthew effect" as two of four co-equal poles in one citation-distortion taxonomy — the closest located source to naming a legitimation-type mechanism and a popularity-type mechanism side by side (see observation-haustein-2016-and-bornmann-leibel-2025-narrow-but-do-not-resolve-citation-bias-matthew-effect-axis-question). The taxonomy's own worked sub-category, however, does not keep the two poles cleanly apart. Under "persuasion hypothesis," relaying White (2004), the authors list "'persuasion with names'... linked to the disproportionate[] citation of works by established authorities to gain credibility through association" — citing a source because it is already recognized, independent of the specific argument being advanced. By content, that behavior is indistinguishable from popularity-selection, the mechanism the same taxonomy's Matthew-effect pole (after Merton) is built to name: "greater increments of recognition for particular scientific contributions to scientists of considerable repute." The taxonomy nonetheless sorts "citing a famous name for credibility" under the persuasion/legitimation pole rather than under its own named Matthew-effect pole.

So even the one outside source the vault has located that places both mechanisms in a single explicit list does not use that pairing to draw a clean line between "selected to support an argument" (legitimation) and "selected because already popular" (popularity): its own worked example shows the two blurring together at exactly the point — authority-based citation — where a clean axis would need them to separate.