Abstract
This study examines how brand entitativity and extension valence shape the feedback effects of brand extensions on parent-brand evaluations, with information accessibility and extension similarity functioning as moderating conditions that jointly govern when and how these effects emerge. Drawing on accessibility - diagnosticity theory and group-level trait transference, it is proposed that high-entitativity brands - perceived as unified, coherent entities - are subject to stronger generalization of extension outcomes than low-entitativity brands. Two experimental studies test these predictions across high- and low-accessibility conditions. Under high-accessibility, extension valence dominates: favorable extensions enhance low-entitativity brands more, while unfavorable extensions damage high-entitativity brands more, regardless of extension similarity - producing full asymmetric feedback effects. Under low-accessibility, extension valence loses dominance and similarity emerges as a critical moderator: only unfavorable dissimilar extensions generate asymmetric effects, with high-entitativity brands suffering greater dilution. These findings establish entitativity and accessibility as interacting determinants of reputational spillover, offer a unified account of mixed findings in the feedback effects literature, and highlight that brand structure and information accessibility jointly govern when and how extension outcomes damage or enhance parent brands.