[Replication] Reassurance Signaling and the Limits of Equilibrium Selection: A Formal Replication of Yoder and Cohen, "Fighting to Be Friends"

Abstract. This paper formally replicates Yoder and Cohen, "Fighting to Be Friends: Third-Party Bargaining, Alliance Formation, and War" (*International Organization*, 2025; DOI 10.1017/S0020818325100817), a signaling model in which a client reassures an uncertain patron by bargaining harder with the patron's rival or softer with its partner. Twenty-seven labeled claims were re-derived across five passes; the model is sound, with all four results and the separating mechanism verifying exactly against the typeset appendix. The contribution is a transportable lesson: endogenizing the reward of a signaling game — making the prize an incentive-constrained later-stage action rather than a scalar — earns the surprise but opens a new surface on which equilibrium selection can fail. The worked instance is Lemma 20, whose divine-refinement elimination is conditional: the comparison reverses on a positive-measure set defined by the model's own type asymmetry, leaving an additional reassurance equilibrium in the characterized set. The comparative statics are untouched.