André Decoster

The Gini Coefficient Reveals More

We revisit the well-known decomposition of the Gini coefficient into between-groups, within-groups and overlap terms in the context of two groups in which the incomes in one group may be scaled and that groupÂ’s population weight modified. In this more general setting than usual, we focus on the properties of the overlap term, proving inter alia that overlap unambiguously reduces as a result of a within-group progressive transfer, and is increased by scaling up the incomes in the group with the lower mean, reaching a maximum when the two means become the same. In the case of a socially heterogeneous population and equivalized incomes, the effect on the Gini overlap of changing the income unit is determined, along with that of adjusting the equivalence scale deflator in case the income unit is the equivalent adult (such adjustment simultaneously changing the weighting of income units). Relationships of the findings to existing literature are thoroughly explored.

Empirical Welfare Analysis in Random Utility Models of Labour Supply

The aim of this paper is to apply recently proposed individual welfare measures in the context of random utility models of labour supply. Contrary to the standard practice of using reference preferences and wages, these measures preserve preference heterogeneity in the normative step of the analysis. They also make the ethical priors, implicit in any interpersonal comparison, more explicit. On the basis of microdata from the Socio Economic Panel (SOEP) for married couples in Germany, we provide empirical evidence about the sensitivity of the welfare orderings to different normative principles embodied in these measures. We retrieve individual and household specific preference heterogeneity, by estimating a structural discrete choice labor supply model. We use this preference information to construct welfare orderings of households according to the different metrics, each embodying different ethical choices concerning the preference heterogeneity in the consumption-leisure space. We then discuss how sensitive the assessment of a hypothetical tax reform is to the choice of metric. The chose tax reform is similar to a subsidy of social security contributions.

A Belgian Flat Income Tax: Effects on Labour Supply and Income Distribution

The adverse distributional effects of a flat tax are well known and have been documented by empirical research in several countries, including Belgium. Advocates of the flat tax argue, correctly, that these studies do not take into account agents’ behavioural reactions and possible feed back effects. One of the important effects in this context is the potential increase in labour supply and the resulting increase in the taxable base and decrease in unemployment allowances. In this study we calculate the cost recovery of the introduction of a Belgian flat tax, based on a micro-simulation model that includes a labour supply model. We find that there is a clearly positive effect on labour supply and hence also on the tax base. By introducing a revenue-neutral flat tax, labour supply increases by approximately 47,000 full-time equivalents. Yet, compared to a static scenario, the cost recovery only allows the revenue-neutral flat tax to decrease from 38.5% to 37%. Furthermore, there is little or no impact of these employment effects on the regressive nature of a flat tax reform.

The evolution of global inequality: absolute, relative and intermediate views

We compare absolute, relative and intermediate views on the evolution of global inequality between 1980 and 2009. According to the relative view, inequality remains invariant after a uniform proportional change of all incomes whereas the absolute view requires invariance to a uniform change of all incomes with the same amount. We use a generic intermediate view which states that an income distribution is as unequal as another one if it can be obtained as a weighted average of a uniform proportional and a uniform absolute change of the incomes. Using recent data on GDP per capita for 115 countries, we …nd considerable support for the claim that world inequality increased for the absolute view and for intermediate views which move substantially in the direction of the relative view.

Why and How to Construct a Genuine Belgian Price Index of House Sales

Assessing the price evolution of houses on the basis of average sales prices, as is current practice in Belgium, might be misleading due to changing characteristics of the houses sold in the periods observed. A hedonic index which takes into account changes in characteristics is more appropriate. We use the budget surveys of the Belgian Statistical Institute to illustrate how this also applies for Belgium. The estimated hedonic price index for house sales on the secondary market is practically always below the index based on average sales values for the period considered. This demonstrates the need to collect more extensive data on the characteristics of the dwellings sold in Belgium.

Welfare effects of alternative financing of social security. Some calculations for Belgium

We analyse the distributional impact of lowering social security contributions and compensating the revenue loss by an increase in indirect taxes. We empirically assess the distributional consequences of this shift by using two Belgian microsimulation models: MODETE for the tax benefit system, and aster for the indirect tax part. Since the underlying micro database of the tax benefit system does not contain expenditures, we first impute detailed expenditures in the income data survey, by means of semiparametric Engelcurves. The currently living generation of pensioners belongs to the losers by such a reform: They do not profit from the reduced tax on labour income, but pay higher consumption prices. Less obvious, also part of the working population loses. Even not all those who leave unemployment after the reform are gainers. We also investigate the sensitivity of the results w.r.t. the choice of welfare measure to assess the combined change in disposable income, consumer prices and - in the case of flexible labour supply - leisure. We show how the specific choice and parameters of the welfare measure will influence the conclusions, possibly even more than the predictive model for assessing the behavioural reactions in labour supply.

Maternal employment: the impact of triple rationing in childcare in Flanders

This paper analyses how maternal labor supply responds to the price and availability of childcare services. It focuses in particular on the childcare market of Flanders, which is characterised by above average childcare use, a wide variety of price schemes and suppliers, and strong government supervision regarding quality. Variation in prices and the degree of rationing of three types of childcare services at the municipal level are used to identify mothers’ labor supply responses. A discrete labor supply model of the Van Soest (1995) type is elaborated to allow for heterogeneity in prices and to distinguish between rationed and non-rationed households. These extensions rest on rationing probabilities that are estimated separately for informal childcare, formal subsidised childcare and formal non-subsidised childcare using partial observability models (Poirier, 1980). The estimates confirm earlier findings for Germany and Italy, indicating only small price effects and relatively large supply effects. This shows that labor supply incentives of expansion of childcare services are also present in a country which has surpassed the EU target of childcare slots for 33% of children below the age of 3 (Belgium, in contrast with Germany and Italy). Moreover, budgetary simulations suggest the expansion to be beneficial to the exchequer. Rising tax and social security benefits following the increase in labor supply largely exceed the costs of expansion.

Indirect Taxes and Social Policy: Distributional Impact of Alternative Financing of Social Security

The role of indirect taxes in social policy is investigated by 1) comparing the distributional pattern of indirect taxes with the one of personal income taxes and social security contributions; 2) calculating the indirect tax liabilities for recipients of social benefits; 3) assessing the distributional impact of shifting the financing of social security from contributions to indirect taxes. For this purpose we combine the data of the Household Budget Survey and the Socio-Economic Panel, as well as two microsimulation models, namely ASTER (for the calculation of indirect taxes) and MISIM (for the calculation of personal income taxes and social contributions)

A Bird's Eye View on 20 Years of Tax-Benefit Reforms in Belgium

Belgium has seen major changes in its tax-benefit system over the past twenty years. These changes have, to a large extent, co-determined the evolution of disposable incomes of Belgian households on one hand, and their incentives to work on the other. In this paper we assess equity and efficiency aspects of changes in tax-benefit policies over the full course of 1992-2012. By simulating effects of current and past tax-benefit policies using the microsimulation model MEFISTO-EUROMOD, we summarize the shifts in policy orientation over this period using two summary measures of redistribution and work incentives. Our three main findings are: 1) the changes in the tax-benefit system have to a large extent been pro-poor and redistribution has been increased; 2) the introduction of an earned income tax credit and the lowering of personal income taxes has contributed to improve work incentives, but this effect was partially eroded by an increase in unemployment benefits since 2000; 3) the results crucially depend on whether one chooses as no policy change counterfactual indexation with inflation or indexation with nominal wage growth.

A Switch from Joint to Individual Taxation Is Welfare Improving

In this paper we empirically derive the welfare effects of a shift from joint taxation with full income splitting to a revenue neutral system of individual taxation in Germany. For the empirical welfare evaluation we estimate the preference heterogeneity in the population and use normative welfare concepts proposed in Fleurbaey (2006) to solve the difficulties of comparison between, and aggregation of heterogeneous individuals and households. We show that, irrespective of the individual welfare measure we use, individual taxation would on average increase individual welfare. Moreover, as far as the aggregation is concerned, we show that any social planner, ranging from a utilitarian to a Rawlsian one, would come to the same conclusion: a policy change which replaces joint taxation with full splitting by individual taxation, would be welfare improving.