累積差額調整税 (Cdat): 累積差額のリアルタイム管理に基づく消費課税の設計仮説[Cumulative Difference Adjustment Tax (CDAT): A Design Hypothesis for Consumption Taxation Based on Real-Time Management of Cumulative Differences]

This paper proposes the Cumulative Difference Adjustment Tax (CDAT) as a design hypothesis that preserves the core principles of the Value Added Tax (VAT)—the suppression of cascading and the taxation of final consumption—while seeking to mitigate its operational burdens. While the current VAT is a highly developed system, it carries structural challenges, including the temporary holding of tax by businesses, refund delays, fraudulent refunds, and the administrative burden of filing and review. CDAT addresses these burdens by recording the tax portion directly in a Treasury Clearing Account without passing through the seller, by continuously managing each business's cumulative difference, and by embedding automatic offsetting as the standard process and immediate settlement as an optional operation by the business. The paper compares CDAT with related institutions, examines tax revenue equivalence under a simplified closed model, analyzes concrete cases including capital investment, exports, mid-course exit, long-term transactions, and B2C transactions, and considers technical implementation with a distributed ledger as the standard specification. In conclusion, CDAT is presented not as an immediate replacement for the current VAT but as a verifiable design hypothesis that, under explicitly stated assumptions, may achieve equivalent cumulative tax revenue outcomes. The further development of fraud detection mechanisms, the specification of transition paths, the legal examination of international consistency, and the quantitative analysis of economic impact remain subjects for future research.