On the Optimality of Mental Accounting

URL SCAN: On the Optimality of Mental Accounting
FIRST LINE: # Economics > General Economics

The Dissection

This paper recasts mental accounting as a strategic commitment against seller markups rather than merely a self-control device. Its result is narrow but coherent: a fixed-dollar budget makes demand unit-elastic, removing the seller’s gain from restricting quantity; budget rigidity, not preference separability, does the protective work.

The Core Fallacy

Relative to the Discontinuity Thesis, the paper treats market power as a pricing problem when it is ultimately an ownership problem. A rigid budget may constrain a markup, but it cannot restore wages, productive participation, bargaining power, or control of AI capital. “Price immunity” inside one category is not sovereignty.

The theorem may hold within its model. The error is extrapolating a local defense against markups into a defense against systemic displacement. An AI-controlled seller can shift exploitation into bundling, personalization, access restrictions, quality degradation, fees, rationing, or category redesign.

Hidden Assumptions

• The consumer has a stable, enforceable dollar budget.
• Categories and products remain fixed and observable.
• The seller cannot profitably use price discrimination, bundling, fees, or dynamic terms.
• The consumer can credibly refuse purchases without losing essential access.
• Market power is static and localized rather than platform-wide.
• The consumer’s main vulnerability is price, not income, access, or ownership.
• Sellers cannot learn and route around the consumer’s commitment rule.

Social Function

Partial truth with a transition-management function. It supplies a real tactical defense against one extraction mechanism while leaving the ownership structure untouched. In DT terms, it helps consumers manage the carcass; it does not prevent the carcass from being created.

The Verdict

An elegant microeconomic result with negligible systemic force. Mental accounting can blunt markups for a bounded basket, but it cannot preserve the wage–consumption circuit or convert a servitor into a sovereign. It is a lock on one pricing valve inside a building whose owner still controls the power grid.