The Story Comes Cheap: Brand Authenticity as a Cost Inference and the Signal Floor for Identity Goods

Perceived brand authenticity is standardly treated as a property consumers detect in brands, and recent work on AI-authored communication has established perceived effort as the step that mediates the penalty. This paper takes cost as the primitive rather than the mediator: authenticity is an inference consumers draw from the production cost of the signal that carries it. It asks what happens to that inference when generative AI drives the cost of the carrying signal toward zero, and derives a single condition — the signal floor — that decides which brand signals still separate authentic from inauthentic senders.