Inequality and the time structure of earnings: evidence from Germany

This paper studies the relationships between annual and subannual inequality and mobility during the course of the year. We apply an exact decomposition framework as outlined in Wodon and Yitzhaki (Econ Bull 4:1–8, 2003), and in Yitzhaki and Wodon (Research on Economic Inequality 12:179–199, 2004). Earnings records of pension insurants in Germany serve as the database. The long time horizon of our database allows us to investigate the stability and robustness of the parameters of the decomposition over time. Specifically, we show that the mobility component of the decomposition, as measured by Gini correlation coefficients, changes over the observation period. This makes it difficult to predict the impact of the income accounting period on inequality in a more general context. Thus, it is of paramount importance to use income data from a uniform accounting period in distributional analyses.     

MEASURING AND ANALYZING CLASS INEQUALITY WITH THE GINI INDEX INFORMED BY MODEL-BASED CLUSTERING

The most widely used measure for studying social, economic, and health inequality is the Gini index/ratio. Whereas other measures of inequality possess certain useful characteristics, such as the straightforward decomposability of the generalized entropy measures, the Gini index has remained the most popular, at least in part due to its ease of interpretation. However, the Gini index has a limitation in measuring inequality. It is less sensitive to how the population is stratified than how individual values differ. The twin purposes of this paper are to explain the limitation and to propose a model-based method—latent class/clustering analysis for understanding and measuring inequality. The latent cluster approach has the major advantage of being able to identify potential "classes" of individuals who share similar levels of income or one or more other attributes and to assess the fit of the model-based classes to the empirical data, based on different cluster distributional assumptions and the number of latent classes. This paper distinguishes class inequality from individual inequality, the type that is better captured by the Gini. Once the classes are estimated, the membership of estimated classes obtained from the best fitting model facilitates the decomposition of the Gini index into individual and class inequality. Class inequality is then measured by two relative stratification indices based on either the relative size of the Gini between-class components or the relative number of stratified individuals. Therefore, the Gini index is extended and assisted by model-based clustering to measure class inequality, thereby realizing its great potential for studying inequality. Income data from France and Hungary are used to illustrate the application of the method.     

INEQUALITY AND TRUST: NEW EVIDENCE FROM PANEL DATA

We estimate the causal link from income inequality to generalized trust by reconsidering the country‐level evidence on this issue. First, we exploit the panel dimension of the data, thus controlling for any country unobservable time‐invariant variables, and find a negative relationship between the two variables that holds only for developed countries. Second, we focus on these advanced economies and provide instrumental variable estimates using the predicted exposure to technological change as an exogenous driver of inequality. According to our findings, the negative causal effect of inequality on trust is even larger than that coming from ordinary least squares estimation. We also provide new insights on the effects of different dimensions of inequality, exploiting measures of both static inequality—such as the Gini index and top income shares—and dynamic inequality—proxied by intergenerational income mobility. (JEL D31, O15, Z13)     

A general class of inequality elasticities of poverty

Many authors have recently emphasized the crucial role of income inequalities in the design of efficient policies aimed at reducing poverty. However, the link between variations in the degree of inequality and variations in poverty is not well documented. The literature, for instance, does not provide any satisfying tool for predicting how a small relative variation in the Gini index may be associated with a variation in the headcount index. In the present paper, we define a family of Lorenz curve transformations that can directly be interpreted in terms of relative variations of known inequality measures. Then, we extend Kakwani’s (Rev Income Wealth 39(2):121–139, 1993) methodology for the calculation of inequality elasticities of poverty. Improvements are threefold with respect to Kakwani’s work. First, our formulas are not confined to the sole Gini index. Secondly, they embrace the uncertainty and the complexity of the mechanical link between inequality and poverty. Third, using some flexible functional form, one can easily perform an accurate estimation of the point inequality elasticities of poverty corresponding to observed variations of a given income distribution. We also propose a simple measure that may be helpful to assess how “pro-poor” are inequality variations by comparing the observed elasticities with the set of theoretical elasticities that could be obtained from the initial income distribution.     

Performance pay,the marriage market and rising income inequality in Taiwan

Taiwan expanded its college access significantly over the past two decades by converting 2-year junior colleges to 4-year colleges and relaxing entrance standards. The share of college graduates in the 22–24 years old population rose from 12 to 71% between 1990 and 2014. This should have suppressed returns to schooling and lowered household income inequality. Instead, Taiwan’s Gini coefficient rose. We show that rising use of performance pay and positive assortative mating in the marriage market jointly increase the household income inequality by 46.5% between 1980 and 2014. Our results suggest that uneven quality of the most recent cohorts of college graduates led to two sources of rising household income inequality: the increased use of bonus pay which increases residual inequality among college graduates; and matching on unobserved skills in the marriage market which increases inequality among married couples.

     

Trend Analysis of Anticipated Lifetime Income Inequality among Post‐war Japanese Youth

This study aims to measure the inequality of anticipated lifetime income and the inequality of annual income among the younger generation (24–29‐year‐old men), and to examine any trends that can be found in terms of inequality between 1955 and 2005 in Japan. Anticipated lifetime income is defined in this study as the present value of the total anticipated annual income that one is likely to earn each year between the ages of 24 and 59 years, assuming that there is no intragenerational class mobility. The anticipated lifetime income for each young male is estimated using the Social Stratification and Social Mobility Survey dataset, which is a Japanese national cross‐sectional survey of social stratification and social mobility. An inequality in the anticipated lifetime income can be regarded as an “inequality of outlook” among the younger generation. As a result of this analysis, it was found that the Gini coefficient, the most general measurement of income inequality, had significantly increased for anticipated lifetime income between 1995 and 2005. At the same time, the gap between the Gini coefficient of anticipated lifetime income and that of annual income had narrowed. It is suggested that “inequality of outlook,” which cannot be easily identified using a superficial index, has increased significantly.     

Source decomposition of changes in income inequality: the integral-based approach and its approximation by the chained Shapley-value approach

This paper proposes source decomposition of the change in income inequality between two time points using the integral-based approach (IBA) and the (chained) Shapley-value approach as its approximation. In comparison to static Shapley-value decompositions and traditional decompositions for the square of the coefficient of variation and the Gini index, the new dynamic Shapley-value approach is intuitively appealing as a decomposition procedure for changes in inequality. It is expected to yield relatively small differences among various inequality measures, essentially maintaining consistency with income source classification. Path dependency, a possible drawback of the new decompositions, is not expected to be a particular problem in the usual cases. The properties are illustrated for application to the increase in US family income inequality during 1979–1996. In this empirical study, the new decompositions showed a tendency that was clearly different from those of the existing decompositions, indicating that the proposed procedures shed new light on analysis of the causes of inequality changes. An extension to incorporate other factors such as family structure is also successful without loss of the desirable properties.     

The impact of unionization,right-to-work laws,and female labor force participation on earnings inequality across states

This study examines the effect of unionization, right-to-work laws, and participation of women in the labor force on income inequality. Two distinct models are developed using 1970 and 1980 census data on the 50 states in the U.S. First, an income inequality model is specified as a beta distribution of the second kind to estimate Gini measures of income inequality. Second, these Gini estimates are used in a simultaneous equations model. The 1970 results indicate that higher unionization rates decreased inequality while right-to-work laws increased inequality. In 1980, the measure of inequality was lower in states with higher female labor force participation. We thank an unknown referee and the editor for comments and criticisms that greatly improved the paper. The usual caveat applies.     

The sensitivity of income polarization

This study looks at polarization and its components’ sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show that polarization has increased over time, regardless of the applied measure, when the last part of the period is compared to the first part of the period; primary causes being increased inequality (alienation) and faster income growth among high incomes relative to those in the middle of the distribution. Increasing the accounting period confirms the reduction in inequality found for shorter periods, but polarization is virtually unchanged, because income group identification increases. Applying different equivalence scales does not change polarization ranking for different years, but identification ranks are affected. The welfare state considerably reduces income polarization and inequality, but at the expense of some more identification.      

TAX POLICY AND INCOME INEQUALITY IN THE UNITED STATES, 1979–2007

This paper assesses the effects of U.S. tax policy reforms on inequality over around three decades, from 1979 to 2007. It applies a new method for decomposing changes in government redistribution into (1) a direct policy effect resulting from policy changes and (2) the effects of changing market incomes. Over the period as a whole, the tax policy changes increased income inequality by pushing up the income share of high‐income earners (the top 20%). (JEL H23, H31, H53, P16)     

Measuring inequality of opportunity through between-group inequality components

Opportunity egalitarians support rich-to-poor redistribution whenever this allows for the compensation of income disparities due to non-responsible choices (circumstances). In this paper we focus on the measurement of opportunity inequality within Roemer’s (Philos Public Aff 22:146–166, 1993) pragmatic theory where a disjoint and exhaustive partition rule is assumed such that individuals within the same population can be grouped depending on the sole circumstances. Given entropy-based, deprivation-based and welfaristic inequality decomposition procedures, we show that the between-group Gini component from Dagum’s decomposition is the only well known between-group inequality index satisfying the Pigou-Dalton principle of transfer as reformulated for opportunity egalitarianism.     

Does income inequality harm health? New cross-national evidence

The provocative hypothesis that income inequality harms population health has sparked a large body of research, some of which has reported strong associations between income inequality and population health. Cross-national evidence is frequently cited in support of this important hypothesis, but the hypothesis remains controversial, and the cross-national work has been criticized for several methodological shortcomings. This study replicates previous work using a larger sample (692 observations from 115 countries over the 1947-1996 period), a wider range of statistical controls, and fixed-effects models that address heterogeneity bias. The relationship between health and inequality shrinks when controls are included. In fixed-effects models that capture unmeasured heterogeneity, the association between income inequality and health disappears. The null findings hold for two measures of income inequality: the Gini coefficient and the share of income received by the poorest quintile of the population. Analysis of a sample of wealthy countries also fails to support the hypothesis.     

Illustrating the Implications of How Inequality is Measured: Decomposing Earnings Inequality by Race and Gender

This paper makes three distinct contributions: it presents a novel modification to an established methodology for assessing inequality using the CPS ASEC data, it illustrates how valuable a multi-metric inequality analysis is by reconciling some open questions regarding the trend in inequality and the role of the composition of income along the distribution, and it provides a baseline assessment of the trend in earnings inequality for four distinct groups of income earners. The evolution of earnings inequality from 1995 to 2010 is compared to increasing inequality in total income as documented by Thomas Piketty and Emmanuel Saez to show that earnings inequality has followed a qualitatively similar, though less extreme trend. In the process, the disconnect between the trend in the Gini coefficient and inequality assessed via the share of income going to the top 1 % of income earners is reconciled through the use of several alternative inequality indices. Finally, the evolution of the earnings distribution for black women, black men, white women, and white men are considered separately, which shows that there are important differences in the experience of inequality. The main findings are that only white men have experienced changes in within-group earnings inequality that parallel the changes in inequality seen in the overall distribution. By contrast, black income earners have seen no notable increase in within-group inequality by any measure, suggesting that they may rightly perceive growing inequality as primarily a between-group phenomena.     

Beyond Oaxaca–Blinder: Accounting for differences in household income distributions

This paper develops a method to decompose differences across distributions of household income, based on counterfactual distributions that ‘lie between’ the actually observed distributions. Our approach decomposes differences between any two income distributions (or functionals such as inequality or poverty measures) into shares due to price effects; occupational structure effects; and endowment effects. Comparing the household income distributions of the USA and Brazil in 1999, we find that most of Brazil’s excess inequality (of 13 Gini points) is accounted for by underlying inequalities in the distributions of education and of non-labor income, notably pensions (between four and six Gini points each). Steeper returns to education in Brazil also make an important contribution (of two to five points). Differences in occupational structure and in racial and demographic composition are much less important. An erratum to this article can be found at     

ACCOUNTING FOR URBAN CHINA'S RISING INCOME INEQUALITY: THE ROLES OF LABOR MARKET,HUMAN CAPITAL,AND MARRIAGE MARKET FACTORS

This paper analyzes China's rising family income inequality since the early 1990s when the urban labor market started its transformation from a centrally controlled to a market‐driven one. We document the trends in income inequality over the period of 1992–2009 using the Urban Household Survey data, and adopt the approach recently proposed by Eika et al. (2014) to decompose changes in income inequality. We find that labor market factors accounted for about three‐quarters of the overall increases in income inequality while falling marriage rate contributed the other quarter. Changes in human capital levels and marital assortativeness have not contributed to the rising inequality. (JEL D31, I26, J12)     

Poverty and economic development: not as direct as it may seem

The relationships among various subsets of economic development, poverty, crime, and/or income inequality have been separately investigated in several theoretical and empirical studies. However, there has been very little empirical analysis on the interdependence among all these variables in one framework. This paper examines the causality between economic development and poverty while incorporating crime and inequality. It employs a co-integration test, a 4-variable vector autoregressive (VAR) model, and a Granger test in the US over the period 1959–2001. Findings reveal a feedback loop mechanism between economic development, poverty, and crime. Interestingly, income inequality as measured by the Gini coefficient has no important impact on any of the variables.     

The measurement of structural and exchange income mobility

Chakravarty, Dutta and Weymark (1985) present operational axioms for an ethical index of income mobility that are best suited for a two period world. This paper suggests a decomposition of this index into two terms: (i) an index of structural or snapshot mobility, which captures the welfare effect of differences in the inequality of the cross-section income distributions; and (ii) an index of exchange or rerankings mobility, which captures the welfare impact of rank reversals between the first- and the second-period income distributions. Income inequality reductions and rank reversals are always welfare enhancing. The properties of all the income mobility concepts introduced in the paper do not require any new value judgements beyond the traditional ones.     

An extended Gini approach to inequality measurement

It is well-known that, when the Lorenz curves do not cross, the ranking of distributions provided by the Gini index is identical to the one implied by the Lorenz criterion. This does not preclude inequality as measured by the Gini index to increase while the Lorenz curves cross. A suitable modification of the Gini coefficient allows the Lorenz quasi-ordering to coincide with the ranking generated by the application of unanimity over the class of extended Gini indices. Recently the Lorenz quasi-ordering and the underlying principle of transfers have come under attack, while new criteria – the differentials, deprivation and satisfaction quasi-orderings – have been proposed for providing unambiguous rankings of distributions. We suggest to weaken the principle of transfers by imposing additional restrictions on the progressive transfers, which take into account the positions on the income scale of the donors and beneficiaries. We identify the subclasses of extended Gini indices that satisfy these weaker versions of the principle of transfers and we show that the application of unanimity among these classes generate rankings of distributions that coincide with those implied by the differentials, deprivation and satisfaction quasi-orderings.      

The Impact of Uruguay's 2007 Tax Reform on Equity and Efficiency

In 2007, the Uruguayan government implemented a tax reform which introduced a new progressive labour income tax and a flat capital income tax, and reduced some indirect taxes, with the objective of improving fiscal balance, income distribution and economic growth. This article evaluates the impact of such tax reform on equity and efficiency on the basis of data derived from the Encuesta Continua de Hogares (ECH) for 2006 and 2009. Using a Difference‐in‐Differences technique, it shows that the new system reduced inequality by 2 Gini points without producing any discernible disincentive effect, suggesting that suitably designed reforms of direct taxation can simultaneously promote equity and efficiency.     

Polarization and the decline of the middle class: Canada and the U.S.

Several recent studies have suggested that the distribution of income (earnings, jobs) is becoming more polarized. Much of the evidence presented in support of this view consists of demonstrating that the population share in an arbitrarily chosen middle income class has fallen. However, such evidence can be criticized as being range-specific—depending on the particular cutoffs selected. In this paper we propose a range-free approach to measuring the middle class and polarization, based on partial orderings. The approach yields two polarization curves which, like the Lorenz curve in inequality analysis, signal unambiguous increases in polarization. It also leads to an intuitive new index of polarization that is shown to be closely related to the Gini coefficient. We apply the new methodology to income and earnings data from the U.S. and Canada, and find that polarization is on the rise in the U.S. but is stable or declining in Canada. A cross-country comparison reveals the U.S. to be unambiguously more polarized than Canada.