The effects of business taxation on economic and social welfare: new insights from tax return data

尽管试图通过削减公共支出和提高其他税收来减少巨大的预算赤字，英国政府仍打算在本届议会任期内将公司税（对公司利润征收的）主要税率从28%降至21%。它这样做是为了“在20国集团中创造最具竞争力的企业税收制度”（内阁府，2010年，第10页）。政府认为公司税对经济活动有重要影响。与此同时，公众对被指逃避缴纳英国公司税的跨国公司表示强烈抗议。这项研究建议估计税收对商业行为（包括避税）的影响程度，以及税收导致的行为扭曲对社会的影响。大部分工作将集中在公司税上，但我们也将分析非法人企业利润的个税和增值税。这项研究的一个关键特征将是使用机密的纳税申报表数据，这些数据最近由英国税务海关总署在一个安全的数据实验室中提供。这些数据的可用性为我们在理解税收对商业行为关键方面的影响方面取得重大突破提供了前所未有的机会。通过与英国税务海关总署（HMRC）合作，我们已经将10年期间的企业纳税申报表数据与同一家公司公布的财务账户数据进行了匹配。对非法人企业纳税申报数据和所有注册企业增值税纳税申报数据进行对接。由此产生的匹配数据集中的信息将处于世界上任何地方可用于商业税收影响实证研究的前沿。拟议中的研究将对营业税对经济和社会福利的影响产生重要的新见解。我们将重点关注商业行为的四个具体领域：投资、资金来源、法律形式的选择（主要是是否成立公司）和避税。我们还将分析应税收入对税率的反应性；这反映了所有的行为反应，可以用来估计商业行为扭曲给社会带来的总体成本。我们将使用统计技术来利用英国营业税的两种形式的变化。首先，我们将利用税收表中几个拐点上边际税率或平均税率的不连续性，包括对利润和损失的不对称处理。其次，我们将利用在过去十年中对每一种税收进行的许多重要改革。部分得益于ESRC之前的投资，牛津大学商业税收中心的研究团队在利用这些数据资源进行创新研究方面处于领先地位。PI指导了HMRC数据实验室的试点项目，该项目率先在对英国公司的实证研究中使用匿名公司纳税申报表数据，研究团队的其他成员现在有了处理这些数据的经验。最终，这项研究的结果应该为营业税的设计提供信息，尽管结果的某些方面也应该有助于确定每种税的管理形式。因此，研究结果对英国财政部和英国税务海关总署（HMRC）以及它们在世界各地的同行都很有用。最近，公众比以往任何时候都更加关注营业税，主要是通过媒体对所谓避税的广泛报道。我们的目标是利用我们的研究来扩大公众对商业税的性质和设计的辩论。

Despite attempting to reduce a very large budget deficit by cutting public expenditure and raising other taxes, the UK government intends to cut the main rate of corporation tax - levied on corporate profit - from 28% to 21% over the life of this Parliament. It is doing so as part of its aim to "create the most competitive corporate tax regime in the G20" (Cabinet Office, 2010, p10). The government believes that the corporation tax has an important impact on economic activity. At the same time, there has been a public outcry over multinational companies that are alleged to have avoided paying UK corporation tax.This research proposes to estimate the scale of the effects of taxes on business behaviour, including avoidance, and also the consequent costs to society of the distortions to behaviour induced by taxes. The majority of the work will focus on corporation tax, but we will also analyse personal taxes on the profits of unincorporated businesses, and VAT. A key feature of the research will be the use of confidential tax return data, recently made available by HMRC in a secure Datalab. The availability of these data provides an unprecedented opportunity for major breakthroughs in our understanding of the effects of taxes on key aspects of business behaviour. In collaboration with HMRC, we have already matched data from the population of corporation tax returns over a 10 year period with data from published financial accounts for the same companies. We will also match the tax return data for unincorporated businesses, and VAT returns for all registered businesses. The information in the resulting matched dataset will be at the frontier of what is available anywhere in the world for empirical research on the effects of business taxation.The proposed research will generate important new insights into the effects of business taxation on economic and social welfare. We will focus on four specific areas of business behaviour: investment, source of finance, choice of legal form (primarily whether to incorporate or not), and tax avoidance. We will also analyse the responsiveness of taxable income to the tax rate; this reflects all behavioural responses, and can be used to estimate the overall costs to society of distortions to business behaviour. We will use statistical techniques to exploit two forms of variation in UK business taxes. First, we will exploit discontinuities in marginal or average tax rates at several kink points in tax schedules, including the asymmetric treatment of profits and losses. Second, we will exploit the many important reforms that have taken place in each of the taxes considered over the last decade.Thanks in part to previous ESRC investments, the research team at the Oxford University Centre for Business Taxation is in an outstanding position to conduct innovative research exploiting these data resources. The PI directed the pilot project of the HMRC Datalab which pioneered the use of anonymised corporation tax return data in empirical research on UK companies, and other members of the research team now have experience of working with these data. Ultimately, the results of this research should be informative in the design of business taxes, though aspects of the results should also be useful in setting the forms of administration of each tax. The results should therefore be useful to HM Treasury and HMRC, and also to their counterparts around the world. Recently the general public has been more engaged with business tax than ever before, mainly through extensive press coverage of alleged tax avoidance. We aim to use our research to broaden the public debate on the nature and design of taxes on business.