For decades, economists treated the household as a single decision-maker, a tidy fiction that let equations balance. The model assumed one set of preferences, as though a family spoke with a single voice when allocating its income. Newer work has dismantled this convenience, showing that spouses often bargain, and that whose name an income arrives in measurably shifts how it is spent. The old model was not so much wrong as incomplete: it described an outcome while ignoring the negotiation that produced it. What looked like unity, the research suggests, was the visible surface of a quieter contest.