Optimal Audit Portfolio Design for a Tax Authority

偷税是一种重要的经济社会现象。HMRC对税收缺口的最新估计显示，税收缺口约为400亿加元，约占总税负的8%。良好的税务管理对于缩小这一差距是必不可少的，但在一些重要方面，现有的学术文献在这方面并不是特别有用。我的目标是构建一个科学合理的分析，并至少在一定程度上通过在优秀期刊上发表高质量的论文来验证。这项研究将是及时的(在2010年支出审查中，已向HMRC提供了9亿GB的额外资源，以解决不遵守规定的问题)，并将有助于实现政府的目标。作为执法行动的一部分，税务机关实施一系列纳税人审计。英国税务机关HMRC目前正在考虑引入一种新的“轻触”审计类别，以补充其传统上实施的更严格的审计类型。税务当局还实施了有针对性的活动，要求税务当局首先获取第三方信息，然后与可能希望根据所获取的信息进行披露的纳税人进行书面沟通。在这场运动中，纳税人被提供了一种激励，以降低所欠税款的惩罚率的形式进行披露。近年来，已经出现了许多这样的运动，包括三个针对拥有离岸账户的纳税人的运动，以及针对特定职业的运动。然而，学术文献还没有正确地理解审计类型组合应该如何构建，以及活动优化设计背后的理论基础。就审计而言，这主要源于逃税标准模型中的一个简化假设，即当税务机关进行审计时，所有不遵守规定的情况都会被自动检测出来。在实践中，审计在发现违规行为方面的有效性与税务机关进行审计的成本之间通常存在负相关关系。拟议的研究将确定税务机关设计干预措施组合以提高合规的最有效方法。为了实现这一目标，将综合运用博弈论和行为经济学的见解。行为经济学将被用来理解由于税务机关的干预，个别纳税人将如何回应他们的合规行为。然后，博弈论将应用于这些见解，以得出最优的投资组合设计。分析将集中在纳税人和税务当局之间的战略互动--纳税人将如何对给定的干预做出反应，以及鉴于此，税务当局应如何以最佳方式设计干预类型的组合，以最大化预期税收。它将适应收入、风险偏好和合规态度不同的纳税人。概述的组成部分将更令人信服地说明关于一系列审计和活动的最佳执行政策。它将提供一个丰富的框架，以便探讨税务机关如何最好地设计其合规运营的问题。与税务合规相比，对最优审计的更广泛见解可以应用于更广泛的执法领域。强大的基于代理的计算机模拟方法将被用来探索更复杂的分析版本的预测，这些分析涉及纳税人的社会网络，而这些分析无法使用传统方法进行分析。未来，我将开发的基于主体的技术可以应用于行为经济学领域的大量问题。最终，这项研究将产生高质量的学术论文和模拟程序，可供税务机关用来改善税收管理。

Tax evasion is an important economic and social phenomenon. The most recent HMRC estimate of the tax gap places it in the region of £40 billion, which is about 8% of total tax liability. Good tax administration is essential for reducing this gap, but in some important respects the existing academic literature is not particularly useful in this context. It is my objective to construct a scientifically sound analysis that will be validated, at least in part, by the publication of high quality papers in good journals. This research will be timely (£900 million of extra resource having been given to HMRC to tackle non compliance in the 2010 Spending Review) and will contribute to government objectives. As a part of their enforcement operations, tax authorities implement a portfolio of taxpayer audits. The British tax authority, HMRC, is currently considering introducing a new category of 'light-touch' audit to complement the more rigorous audit types it has traditionally implemented.Tax authorities also implement targeted campaigns that entail an initial acquisition of third-party information by the tax authority, followed by written communication with those taxpayers who might potentially wish to make to make a disclosure in the light of the information acquired. Taxpayers are offered an incentive to make a disclosure under the campaign in the form of a lower penalty rate on the tax owed. Recent years have seen a number of such campaigns, including three aimed at taxpayers with offshore accounts, and campaigns aimed at particular professions. However, the academic literature is yet to properly understand how a portfolio of audit types should be constructed, and the theoretical underpinnings behind the optimal design of campaigns. In the case of audits, this principally stems from a simplifying assumption in the standard model of tax evasion that, when the tax authority performs an audit, all non-compliance is automatically detected. In practice, there is generally a negative relationship between the effectiveness of an audit at detecting non-compliance and the cost of performing it to the tax authority.The proposed research will identify the most effective way for a tax authority to design a portfolio of interventions so as to enhance compliance. To achieve this, a mixture of insights from game theory and behavioural economics will be applied. Behavioural economics will be used to understand how individual taxpayers will respond in their compliance behaviour as a result of an intervention by the tax authority. Game theory will then be applied to these insights to derive the optimal portfolio design. The analysis will centre on the strategic interaction between taxpayers and the tax authority - how taxpayers will respond to a given intervention, and, given that, how the tax authority should optimally design a portfolio of intervention types so as to maximise expected tax revenue. It will accommodate taxpayers who are heterogeneous in income, risk preferences, and attitudes towards compliance. The components outlined will provide a more compelling characterisation of optimal enforcement policy with respect to a portfolio of audits and campaigns. It will provide a rich framework in which to pursue the question of how best a tax administration can design its compliance operations. The wider insights into optimal auditing can be applied to a wider set of enforcement domains than tax compliance. Powerful agent-based computer simulation methods will be utilised to explore the predictions of more complex versions of the analysis involving social networks of taxpayers, which cannot be analysed using conventional methods. The agent-based techniques I will develop can, in future, be applied to a large range of questions in the field of behavioural economics. Ultimately, the research will produce high quality academic papers, and simulation programs that can be used by tax authorities to improve tax administration.