Mental Accounting in Personal Finance
Mental accounting examines how individuals categorize, label, and evaluate money in separate psychological accounts rather than treating all financial resources as fully fungible. This article explores the concept’s foundations in behavioral economics, its challenge to the classical fungibility assumption, its role in consumer behavior, windfall spending, time preferences, personal finance, and behavioral policy, and its importance for institutional design. It also develops a formal analytical framework for mental accounting and includes substantial R and Python sections with fully commented code for simulating windfalls, labeled savings, debt persistence, and segmented versus unified money views. The broader argument is that mental accounting is not a minor quirk of personal finance, but one of the central ways real people structure economic decision-making.









