Updating and critiquing HMRC’s analysis of the UK’s 50% top marginal rate of tax
Updating and critiquing HMRC’s analysis of the UK’s 50% top marginal rate of tax
复制标题
更新和批评 HMRC 对英国 50% 最高边际税率的分析
DOI：
10.1920/wp.ifs.2017.w1712
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发表时间：
2017
期刊：
影响因子：
7.3
通讯作者：
David Phillips
中科院分区：
文献类型：
--
作者：
J. Browne;David Phillips
2010年4月，英国超过15万英镑的所得税边际税率从40%提高到50%，影响了0.66%的最高收入成年人（和1%的所得税纳税人）。这似乎是估算应税收入弹性的理想机会，但由于提前一年多宣布改革，导致提前（个人将收入结转到税率提高前一年），这阻碍了识别。这阻碍了HMRC（英国税务当局）使用更高税率第一年（2010-11）的不完整数据来估计税收增加的收入影响（HMRC，2012）的尝试。这一分析采用了差异中差异的总体方法。在本文中，我们更新了这一分析，使用了改革后第一年（2010-11年）的更完整数据和HMRC进行分析时无法获得的另一年（2011-12年）的数据。使用与HMRC（2012）类似的方法，我们根据2010-11年度的响应估计弹性约为0.31，根据2011-12年度的响应估计弹性约为0.83。接下来，我们将改进HMRC（2012）的方法，以估计有多少被阻止的收入来自2010-11年，以及有多少来自随后几年。我们发现，在其他条件相同的情况下，HMRC估计收入来自哪些年份的方法-这表明大约70%来自2010-11年-可能会导致高估改革后最初几年的收入，因此低估了潜在的应税收入弹性。另一种更好地解释这些问题的方法表明，2010-11年约有45%的资金被解冻，2011-12年约有六分之一的资金被解冻，这意味着基于2010-11年的回应弹性为0.58，基于2011-12年的回应弹性为0.95。这都意味着最高税率提高到50%会带来负收入。最后，我们展示了HMRC（2012）估计对用于估计受50%税率影响的群体的反事实收入的模型规格变化的敏感性。我们发现，相对较小的变化规格产生非常不同的结果，较高的应税收入弹性估计经常超过统一。因此，英国预算责任办公室（Office for Budget Responsibility）可以用来估计英国最高所得税率变化对收入影响的合理中央估计范围很广。然而，在此必须提出三点警告。首先，如果个人（正确地）预计到50%的税率将在以后几年降低（或者能够对2011-12纳税年度结束时宣布的2013-14年将降至45%的公告做出回应），他们也可能推迟收到收入。当我们假设个人能够从2011 - 12年推迟到2013-14年的收入与他们能够从2011 - 12年提前到2009-10年的收入一样多时，我们仍然获得比HMRC（2012）更高的应税收入弹性估计，但可能是推迟收入比提前收入更容易。如果是这种情况，对50%税率的总体反应可能更多地代表暂时的时间效应，而不是潜在的反应，这意味着对潜在应税收入弹性的估计可能被高估。第二，一些行为反应，如增加职业养恤金缴款，或将收入保留在企业中，虽然在短期内减少了所得税收入，但在长期内至少产生了一些收入。第三，反事实的估计是非常不精确的定义，这意味着不同规格的估计在统计上彼此没有显著差异，或者实际上从零开始。因此，HMRC（2012）的中心估计仍然在我们估计的误差范围内。因此，围绕HMRC对高收入者应纳税收入弹性的估计，以及50%税率的收入影响，在两个方向上都存在很大的不确定性。
In April 2010 the UK's marginal rate of income tax above £150,000 was increased from 40% to 50%, affecting the highest-income 0.66% of the adult population (and 1% of income taxpayers). This would seem an ideal opportunity to obtain an estimate of the taxable income elasticity, but identification is impeded by forestalling (individuals bringing forward income to the year before the tax rate was increased) resulting from the reform being announced more than a year in advance. This forestalling hampered an attempt by HMRC (the UK’s tax authority) to estimate the revenue effects of the tax rise (HMRC, 2012) using incomplete data from the first year of the higher tax rate (2010–11). This analysis used an aggregate difference-in-difference approach. In this paper we update this analysis, using more complete data on the first year following the reform (2010–11) and an additional year of data (2011–12) that was unavailable when HMRC conducted their analysis. Using a similar method to HMRC (2012), we estimate an elasticity of around 0.31 based on the response in 2010–11, and 0.83 based on the response in 2011–12. We next refine HMRC (2012)’s methodology for estimating how much of the forestalled income came from 2010–11 and how much from subsequent years. We find that all else equal, HMRC's method for estimating from which years forestalled income came – which suggests that around 70% came from 2010–11 – is likely to lead to overestimates of how much came from these initial post-reform years, and hence underestimate the underlying taxable income elasticity. An alternative method that better accounts for these issues suggests around 45% was unwound in 2010–11, and around one-sixth unwound in 2011–12, implying an elasticity of 0.58 based on the response in 2010–11 and 0.95 based on the response in 2011–12. These would both imply negative revenues from the increase in the top tax rate to 50%. Finally, we show the sensitivity of HMRC (2012)’s estimates to changes in the specification of the model used to estimate the counterfactual incomes of the group affected by the 50% tax rate. We find that relatively small changes to the specification yield very different results, with higher taxable income elasticity estimates frequently in excess of unity. The range of reasonable central estimates that the UK’s Office for Budget Responsibility could use to estimate the revenue effects of changes to the UK’s top income tax rate is therefore wide. However, it is important to sound three notes of caution here. First, if individuals anticipated (correctly) the 50% rate being reduced in later years (or were able to respond to the announcement made towards the end of the 2011–12 tax year that it would be reduced to 45% in 2013–14), they may also have delayed receiving income. We still obtain higher taxable income elasticity estimates than HMRC (2012) when we assume that individuals were able to delay as much income from 2011–12 to 2013–14 as they were able to bring forward from 2011–12 to 2009–10, but it may be the case that delaying income is easier than bringing it forward. If this were the case, more of the overall response to the 50% tax rate may represent temporary timing effects as opposed to underlying response, which would imply that the estimates of the underlying taxable income elasticity may be overestimates. Second, some behavioural responses, such as additional occupational pension contributions, or retention of income in businesses, while reducing income tax revenues in the short-term, generate at least some revenue in the longer-term. Third, the estimate of the counterfactual is very imprecisely defined, meaning that the estimates from the different specifications are not statistically significantly different from each other, or indeed from zero. The central estimates of HMRC (2012) are therefore still very much within the margin of error of our estimates. There is therefore still significant uncertainty in both directions around HMRC’s estimates of the taxable income elasticity of high earners, and hence the revenue effects of the 50% rate.