Measuring revenue responses to tax rate changes in multi-rate income tax systems: behavioural and structural factors

This paper shows how income changes in response to changes in marginal income tax rates (MTRs) translate into tax revenue changes for the familiar multi-step income tax function used in many countries. Previous literature has focused on the relatively straightforward case of a proportional income tax or the top MTR only. The paper examines revenue responses at both the individual and aggregate levels, and it is shown that for individual MTRs within a multi-rate regime, simple expressions for tax revenue responsiveness can be derived that nevertheless capture the various behavioural and structural responses to income tax reforms involving changes to multiple rates and thresholds. Illustrations are provided using changes to the New Zealand income tax structure in the 2010 budget. This reduced all marginal tax rates while leaving income thresholds unchanged.     

Personal income tax mimicry: evidence from international panel data

This paper investigates personal income tax (PIT) mimicry at the international level. It is the first to empirically investigate the extent to which PIT mimicry varies along the tax schedule and the first to include nations which are not part of the OECD. We use data on international personal income tax schedules from the world tax indicators to estimate marginal and average tax rates at various multiples of per capita gross domestic product (GDP). These tax rates are then used to estimate the extent to which countries respond to their neighbors’ PIT policy. We find evidence of PIT mimicry using a balanced panel of 53 countries over 24 years. This finding is strongest for tax rates at lower multiples of per capita GDP and survives several robustness checks.     

2000～2008年OECD成员国个人所得税变化及对我国的启示

本文通过对2000～2008年OECD成员国个人所得税变化的分析,得出OECD成员国低收入纳税人税负下降、高收入纳税人税负上升,个人所得税最高边际税率普遍下降、税率档次进一步减少、税收累进性提高等结论。借鉴OECD成员国经验并结合我国国情,认为我国个人所得税的功能应定位于调节收入分配,并就如何提高我国个人所得税累进性提出了相关政策建议。     

The Elasticity of Taxable Income in New Zealand*

This paper reports estimates of the elasticity of taxable income with respect to the net‐of‐tax rate for New Zealand taxpayers. The relative stability of the New Zealand personal income tax system, in terms of marginal rates, thresholds and the tax base, provides helpful conditions for deriving these estimates. The elasticity of taxable income was estimated to be substantially higher for the highest income groups. Changes in the timing of income flows for the higher income recipients were found to be an important response to the announcement of a new higher rate bracket. The marginal welfare costs of personal income taxation were consistent across years, being relatively small for all but the higher tax brackets. For the top marginal rate bracket of 39 per cent, the welfare cost of raising an extra dollar of tax revenue was estimated to be well in excess of a dollar. Implications of the findings are that: disincentive effects of high top marginal rates can be substantial even when labour supply responses are small; the welfare costs of increases in top marginal tax rates can be high; and announcement effects of tax policy changes can lead to considerable income shifting between time periods.     

The tax benefit of income smoothing

A worker can reduce tax liability by contributing to a private pension plan when marginal tax rates are high and withdraw pension benefits when marginal tax rates are low. We quantify the tax benefit of income smoothing through the private retirement system and find that it is negligible. This conclusion is important to households, investment advisers, tax policymakers, and scholars engaged in financial retirement planning.     

Optimal redistributive tax and education policies in general equilibrium

This paper studies optimal linear and non-linear income taxes and education subsidies in two-type models with endogenous human capital formation, endogenous labor supply, and endogenous wage rates. Assuming constant human capital elasticities, human capital investment should be efficient under optimal linear policies, whether general equilibrium effects are present or not. Hence, education subsidies should not be used for distributional reasons. Due to general equilibrium effects, optimal linear income taxes may even become negative. Optimal non-linear policies exploit general equilibrium effects for redistribution. The high-skilled type optimally has a negative marginal income tax rate and a positive marginal education subsidy. The low-skilled type optimally faces a positive marginal income tax rate and a marginal tax on education. Simulations demonstrate that general equilibrium effects have only a modest effect on optimal non-linear policies.     

On the construction of marginal federal personal and social security tax rates in the U.S

In this article, I correct and extend my earlier series on marginal federal personal income tax rates. I also construct a measure of the marginal Social Security tax rate and add this to the income tax rate to obtain a measure of the effective marginal tax rate on income due to federal taxes. Finally, I compare my series on marginal income tax rates and its method of construction with those of Barro and Sahasakul.     

Why Are Mothers Working Longer Hours in Austria than in Germany? A Comparative Microsimulation Analysis*

Labour force participation rates of mothers in Austria and Germany are similar; however, full‐time employment rates are much higher among Austrian mothers. In order to find out to what extent these differences can be attributed to differences in the tax‐transfer system, we perform a comparative microsimulation exercise. After estimating structural labour supply models for both countries, we interchange two important institutional characteristics of the two countries ‐ namely, (i) the definition of the tax unit within the personal income tax and (ii) the parental leave benefit scheme. As our analysis shows, differences in mothers’employment patterns can partly be explained by the different tax systems: while Germany has a system of joint taxation with income splitting for married couples, Austria taxes everyone individually, which leads to lower marginal tax rates for secondary earners than in the German system.     

Optimal taxation and top incomes

In many high-income countries over the past three decades there has been both large growth in inequality of wages and income and a shift in the burden of taxation from the top to the middle of the income distribution. A literature has developed which focuses on optimal tax rates for the top 1 % of the income distribution. In contrast, this paper considers the effect of inequality growth on the structure of a piecewise linear tax system defined over the entire income distribution. Our results suggest that the appropriate response to the increases in inequality would have been a shift towards a tax system with a lower tax rate in the lower half of the distribution together with a highly marginal rate progressive structure in the upper half, a clear differentiation between the top 10 % and the top 1 % and a higher top tax rate. Further inequality growth strengthens these characteristics of the optimal tax structure.     

MEASURING CORPORATE TAX RATES AND TAX INCENTIVES: A NEW APPROACH

Taxes play an important but underemphasized role in the valuation of a company and its projects. For example, the authors estimate that the expected tax benefits from interest deductions by all publicly traded U.S. corporations were responsible for almost $1.4 trillion of their total market value of $12.7 trillion in 1991. In the case of RJR's 1989 leveraged buyout alone, the capitalized value of the interest tax shield amounted to several billion dollars (or about 25%) of the company's market value.
This article argues that, to maximize shareholder wealth, the corporate planning process should include a careful analysis of corporate tax incentives. Using several examples, the authors show how earnings variability and major provisions of the tax code interact to affect a company's expected marginal tax rate. After describing the complexities involved in properly calculating corporate tax rates, the article concludes by describing a simulation method the authors have developed to measure a company's effective marginal tax rate and, hence, its tax incentives to use more leverage (or some other means of reducing taxable income).
In furnishing a method for calculating marginal tax rates with greater accuracy, the authors also provide a clue to resolving the capital structure puzzle discussed in the roundtable at the head of this issue. In particular, their recent research corrects earlier studies in the finance literature by showing that when marginal tax rates are measured before financing (that is, based on income before interest expense is deducted), there is a positive relation between debt usage and tax rates.     

Joint Taxation and the Labour Supply of Married Women: Evidence from the Canadian Tax Reform of 1988*

The Canadian federal tax reform of 1988 replaced a spousal tax exemption with a non‐refundable tax credit. This reduced the‘jointness’of the tax system: after the reform, secondary earners’effective‘first dollar’marginal tax rates no longer depended on the marginal tax rates of their spouses. In practice, the effective‘first dollar’marginal tax rates faced by women with high‐income husbands were particularly reduced. Using difference‐indifference estimators, we find a significant increase in labour force participation among women married to higher‐income husbands.     

Reinsurance and corporate taxation in the United Kingdom life insurance industry

There are two main tax-related arguments regarding the use of reinsurance – the income volatility reduction and the income level enhancement arguments. The income volatility reduction argument contends that firms facing convex tax schedules have incentives to hedge in order to reduce the volatility of their annual taxable income and thereby lower expected tax liabilities [Smith, C.W., Stulz, R.M., 1985. Optimal hedging policies. Journal of Financial and Quantitative Analysis 19, 127–140]. The income level enhancement argument, advanced by Adiel [Adiel, R., 1996. Reinsurance and the management of regulatory ratios and taxes in the property–casualty insurance industry. Journal of Accounting and Economics 22, 207–240], is more specific to hedging via reinsurance. This perspective holds that reinsurance enhances current reported earnings via the receipt of reinsurance commissions and so increases tax liabilities. Consequently, insurance firms with high marginal tax rates should use less reinsurance than those with low marginal tax rates if tax matters. Prior studies using data on financial derivatives have produced mixed results on the validity of the first argument, while Adiel (1996) finds the second argument insignificant in his study of the use of reinsurance by a sample of United States (US) property–liability insurance firms. This study tests the two tax-related arguments using 1992–2001 data for a sample of United Kingdom (UK) life insurance firms. We find that UK life insurers with low before-planning marginal tax rates tend to use more reinsurance; in contrast, tax convexity is found to have no significant impact on the purchase of reinsurance and so the volatility-reduction argument is not supported.     

Direct evidence on the marginal rate of taxation on dividend income

Miller and Scholes (1978) hypothesize that the marginal tax rate on dividend income may be less than the marginal rate of tax on capital gains. Their hypothesis is dependent upon individuals utilizing existing provisions of the Code which serve to reduce the taxation of dividends. In this study, estimates of the marginal and effective rates of tax on dividend income for the year 1979 are presented using the Statistics of Income sample of returns. The average marginal rate of tax on dividend income is estimated to be 40%, while the average effective rate of tax is estimated to be 30%.     

Optimal taxation and redistribution in an OLG model with unemployment

This paper concerns redistribution via nonlinear income taxation in an overlapping generations model with two ability-types. We assume that the wage rates are determined by bargaining between unions and firms, meaning that the equilibrium is characterized by involuntary unemployment. We show that the policy instruments that are used to calculate the marginal labor income tax rate for each ability-type give rise to intertemporal tax base effects. In addition, since the relationship between the employment and the capital stock implies intertemporal production inefficiency at the second best optimum, imperfect competition in the labor market may itself justify capital income taxation.      

An International Study of Tax Effects on Government Bonds

It is shown that coupon bonds alone are not sufficient to span time-dated claims on ordinary income, capital gains, and non-taxable wealth. In an incomplete bond market where the pure dated claims are not spanned by existing bonds, marginal rates of substitution between present consumption and pure dated claims on ordinary income, capital gains income, and non-taxable wealth, respectively, can differ across bondholders. However, the relative pricing of coupon bonds in each of these countries is shown to be consistent with the tax status of the major (non-tax-exempt) holders of government debt.     

Tax Reform and the Demand for Debt

This article examines the impact on household borrowing from a tax reform that implied a change from progressive to constant marginal tax rates on interest deductions. We use three alternative empirical methods to address the problem of endogenous explanatory variables, which arises when the marginal tax rate itself is a function of the amount of debt: The first approach uses instrumental variables to examine the significance of the marginal tax rate directly and produces mixed results. In the second approach we use tobit regressions based on repeated cross-sectional data to examine the correspondence between debt and income and find that the households' amount of debt were strongly and positively related to income before the tax reform and significantly more income-dependent under progressive tax rates than under the constant tax rate. Finally, using panel data covering the last year prior to the reform and the first year after, we find that the change in a household's marginal tax rate had a significant impact on the change in its amount of debt.     

On the design of an optimal non-linear tax/pension system with habit formation

We study the optimal tax/pension design in a two-period model where individuals differ in both productivity and discount rates or projection bias and where their utility of the retirement period consumption is not independent of the earlier standard of living. We consider both welfarist and paternalistic social objectives. The paternalistic government attempts to correct the projection bias by using a higher discount factor. We derive general mathematical expressions that characterize optimal tax/pension design (marginal tax/subsidy rates). They suggest that the pattern of marginal labor income taxes depends on habit formation. Negative marginal labor income tax rates are possible. To gain a better understanding, we examine numerically the properties of an optimal lifetime redistribution policy with habit formation. We find support for non-linear tax/pension program in which some types of individuals are taxed while some are subsidized. The effect of changes in the degree of habit formation is explored in the numerical simulations as well as the implications of different degrees of correlation between skill and projection bias.     

An analysis of nondeductible IRA contributions and Roth IRA conversions

On average investors have an income replacement rate of 64% of their pre-retirement income, which in many cases results in a lower tax rate in retirement. We analyze the impact of declining withdrawal tax rates on the choice between taxable mutual fund investments and nondeductible IRAs. The relative attractiveness of the taxable mutual fund option declines significantly when withdrawal tax rates decline. Converting existing IRAs to Roth IRAs is generally beneficial for investors who remain in the same tax bracket upon withdrawal. For short (long) time horizons and low (high) expected returns, the marginal value of conversion in 1998 is greater (less) than the marginal value of optimal conversion. For investors dropping into the 15% tax bracket, conversion is generally not beneficial unless the conversion is done optimally, the time horizon is long, and the expected return is high. Investors in the 15% tax bracket should convert existing IRA assets.     

The Elasticity of Marginal Utility of Consumption: Estimates for 20 OECD Countries*

In social project appraisal, the policy profile of both distributional welfare weights and the social discount rate has risen considerably in recent years. This fact has important implications for the allocation of funds to social projects and policies in countries, and in unions of countries such as the EU. A key component in the formulae for both welfare weights and the social discount rate is the elasticity of marginal utility of consumption, e. A critical review of existing evidence on e suggests that the UK Treasury's preferred value of unity is too low. New evidence presented in this paper, based on the structure of personal income tax rates, suggests that, on average, for developed countries e is close to 1.4. This particular approach to the estimation of e has previously been under‐utilised by researchers.     

EVIDENCE ON THE EFFECT OF TAXES ON FIRMS' DECISIONS TO RETIRE DEBT EARLY

We examine the effect of marginal tax rates on the decision to retire debt early. Other factors that have been linked to the debt retirement decision are also investigated, including leverage adjustment and the value associated with the immediate recognition of a loss for tax purposes on early retirement. Results indicate that firms that retire debt early have lower marginal tax rates than firms that do not retire debt early. This finding is consistent with the proposition that firms are motivated to retire debt early by an incentive to reduce tax shields that cannot be used efficiently. Further, firms that retire debt early are more highly leveraged than firms that do not retire debt early. Evidence also suggests that some firms retire debt early at a loss to reduce currently taxable income.