Theoretical Study on International Differences in Non-Deductible Expenses

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K02047
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 07100:Accounting-related
• Research Institution: Keio University
• Principal Investigator: MURAKAMI Yutaro 慶應義塾大学, 経営管理研究科(日吉), 准教授 (30434591)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 契約理論 / 損金不算入制度 / 政策変更の柔軟性

Outline of Final Research Achievements

This study analyzes how a tax system, in which expenses associated with business activities are only partially deductible for tax purposes, affects corporate behavior, including the effort level and compensation contracts. Since these activities create firm value and benefit the agent due to the inherent characteristics of consumption goods, the principal faces a trade-off between letting agents work with high-powered incentives and the tax payments resulting from non-deductible expenses. Further, we consider a government's behavior to analyze the case in which the government can flexibly change the non-deductible ratio. We find that the impacts of the corporate tax rate and the agent's preference for activities that incur tax non-deductible expenses depend on whether the non-deductible ratio is flexible. This result partially explains why various countries apply different rules for non-deductible expenses.

Free Research Field

税務会計

Academic Significance and Societal Importance of the Research Achievements

本研究の学術的意義は大きく2つある。第一に、費用の損金不算入制度が、インセンティブ率、エージェントの努力水準、プリンシパルの期待効用にどのような影響を与えるかを分析したことである。固定報酬の一部が損金不算入となるケースを分析した先行研究はあるが、事業活動に伴う経費が損金不算入となるケースを分析した研究は、私の知る限り存在しない。第二に、本研究では、政策を柔軟に変更できる政府が損金不算入割合を決定するケースを検討した。その結果、税率が企業行動に与える影響は、政府が損金不算入率を柔軟に変更できるか否かによって異なることが分かった。この結果は、国によって損金不算入のルールが異なる理由を説明できる。