Advances in Inequality Measurement and Usefulness of Statistical Inference

Assessment of inequality measurement is the focus for this survey. All measures of inequality must be evaluated based on a set of desirable properties. More importantly, the usefulness of statistical inference for measures of inequality needs examination.

Advances in Inequality Measurement and Usefulness of Statistical Inference

Assessment of inequality measurement is the focus for this survey. All measures of inequality must be evaluated based on a set of desirable properties. More importantly, the usefulness of statistical inference for measures of inequality needs examination.     

On the dynamics of inequality

The dynamics of inequality are studied in a model of human capital accumulation with credit constraints. This model admits a multiplicity of steady state skill ratios that exhibit varying degrees of inequality across households. The main result studies equilibrium paths. It is shown that an equilibrium sequence of skill ratios must converge monotonically to the smallest steady state that exceeds the initial ratio for that sequence. Convergence is “gradual" in that the steady state is not achieved in finite time. On the other hand, if the initial skill ratio exceeds the largest steady state, convergence to a steady state is immediate.This paper is based on unpublished notes from 1990; see http://www.econ.nyu.edu/user/debraj/DevEcon/Notes/incdist.pdf. Two considerations suggest that these results may be worth reporting in print. First, the existence of a sizeable recent literature indicates that these relatively early notes may have value outside a filing cabinet or a private webpage. Second, Mukul Majumdar’s own research on economic growth with a nonconvex technology is an even earlier precursor to some of this literature, so the current outlet – a special issue in his honor – seems appropriate. Conversations with Glenn Loury simplified the proof of the main result. I thank Dilip Mookherjee for many useful discussions, and two anonymous referees for helpful comments on an earlier draft. Funding from the National Science Foundation under grant number 0241070 is acknowledged. This paper is dedicated with much affection and warm admiration to Mukul Majumdar – or to Mukulda, as I always think of him – on the occasion of his 60th birthday.     

Poverty decompositions with counterfactual income and inequality dynamics

Traditional poverty accounting decomposes changes in a country's poverty headcount ratio into changes in income and inequality. We argue that this approach is unsatisfactory from the perspective of policy analysis because it compares a country in two points of time without taking the country's initial situation, and hence its potential for poverty reduction, into account. We thus suggest comparing traditional poverty decompositions with a counterfactual situation. This counterfactual indicates what a country starting from its initial situation could be expected to achieve in terms of income, inequality, and, hence, poverty developments. We construct those counterfactuals by modeling income and inequality trends characterized by convergence and a “Kuznets” relationship between inequality and development. Parameters in those relationships are estimated using PovcalNet survey data from 144 countries and we construct our counterfactual poverty predictions for 71 developing countries. While there is overall a tight relationship between actual developments and counterfactuals, we identify several cases, where both deviate from each other and discuss the policy implications. We also check for commonalities in differently performing countries and find that those who fell particularly short of expectations often underwent political transition and state fragility.     

Market volatility and inequality in earnings: experimental evidence

We analyze the volatility of actions in experimental oligopoly markets. Can the volatility, measured as the total variation in actions, be predicted by inequality in earnings of the previous period? We examine two types of differentiated markets, Cournot and Bertrand, and two informational conditions. We find for both types of markets and regardless of the information available to firms that inequality in earnings is a major factor for explaining volatility. The more equal profits are distributed, the less volatility is observed.     

The price of education and inequality

Constructing a simple model that includes the price of education, this paper shows that the educational expenditure of rich households could prevent poor households from escaping poverty. The paper offers an explanation for persistent inequality.     

On factor decomposition of cross-country income inequality: some extensions and qualifications

In a recent paper in this journal Duro and Esteban [Econom. Lett. 60 (1998) 269] have proposed a factor decomposition of the Theil [Economics and Information Theory, Amsterdam, North-Holland, 1967] index of inequality over per capita incomes into the (unweighted) sum of the inequality indexes of the factors in order to measure the contribution of each individual factor to the overall inequality. The purpose of this little note is to extend and qualify the meaning of such a decomposition, to show that the decomposition also holds for another Theil [Economics and Information Theory, Amsterdam, North-Holland, 1967], index of inequality and that both decompositions offer qualitatively the same general results about the contribution of the factors to aggregate inequality when applied to a particular data set, the OECD countries, although quantitative results differ.     

A note on the evolution of inequality in Poland, 1992-99

Analyses of household budget surveys, national accounts dataon functional income distribution, and data on the dispersionof wages, indicate that income inequality in Poland, after fallingover the 1993–96 period, rose significantly from 1997onwards. Farmers and the unemployed were the main losers. Theoverall position of wage-earners improved, although wage inequalityincreased sharply in the second half of the 1990s. Employersand the self-employed fared quite well. This coincided withfiscal policy changes which substantially slowed down progressionin income taxes. Over the 1993–96 period growth was highand balanced. Subsequently, growth slowed down, giving riseto serious fiscal and external deficits.     

Income, income inequality, and health: Evidence from China

This paper tests using survey data from China whether individual health is associated with income and community-level income inequality. Although poor health and high inequality are key features of many developing countries, most of the earlier literature has drawn on data from developed countries in studying the association between the two. We find that self-reported health status increases with per capita income, but at a decreasing rate. Controlling for per capita income, we find an inverted-U association between self-reported health status and income inequality, which suggests that high inequality in a community poses threats to health. We also find that high inequality increases the probability of health-compromising behavior such as smoking and alcohol consumption. Most of our findings are robust to different measures of health status and income inequality. Journal of Comparative Economics 34 (4) (2006) 668–693.     

Multidimensional inequality with variable population size

Summary. We study inequality in a context of more than one variable by extending a celebrated result of Hardy, Littlewood and Pölya (1934) to the case of distributions with variable population sizes, whose individuals differ in many characteristics besides income. A new ordering between rectangular matrices, representing such distributions, is provided and characterized by convexity theory.Received: 19 October 2003, Revised: 7 September 2004, JEL Classification Numbers: D31, D63, I31.I am indebted to C. d’Aspremont, V. Dardanoni, G. Koshevoy, K. Mosler and especially J. Weymark and an anonymous referee for many useful comments.     

Income inequality and crime in the United States

This paper investigates the relationship between income inequality and crime. Results show that there is a strong and robust effect of relative income inequality on burglary. Effect on robbery is also strong and robust in most cases.     

Finance and inequality: Channels and evidence

We provide a framework to interpret the recent literature on financial development and inequality. In many developing countries, access to funding and financial services by firms and households is still very skewed. Recent evidence suggests that poor access does not only reflect economic constraints but also barriers erected by insiders. Inequality affects the distribution of political influence, so financial regulation often is easily captured by established interests in unequal countries. Captured reforms deepen rather than broaden access, as small elites obtain most of the benefits while risks are socialized. Financial liberalization motivated to increase access may in practice increase fragility and inequality, and lead to political backlash against reforms. Thus financial reforms may succeed only if matched by a buildup in oversight institutions. Journal of Comparative Economics 35 (4) (2007) 748–773.     

The creation of effective states in the OECD since 1870: The role of inequality

Research shows that state capacity is crucial for economic development, yet the impact of inequality on state capacity is not well understood. This paper examines the impact of income inequality on three key dimensions of state capacity, namely legal, fiscal and collective capacity using annual data for a core of 21 OECD countries over the period 1870–2013. We find that the marked reduction in inequality over most of the last century starting from 1916 was pivotal to the significant improvements in legal, fiscal and collective capacity in the OECD countries over the same period.     

Economic inequality in Spain: the european community household panel dataset

This article uses data from the 1998 European Community Household Panel to study economic inequality in Spain. It reports data on the Spanish distributions of income, labor income, and capital income, and on related features of inequality, such as age, employment status, educational attainment, and marital status. It also reports data on the income mobility of Spanish households, and data on income inequality in other European countries and in the US. We find that income, earnings, and, especially, capital income are very unequally distributed in Spain and that economic inequality in Spain is well above the European average.     

The subgroup decomposable intermediate indices of inequality

An inequality index is called subgroup decomposable if it can be expressed as a weighted sum of inequality values calculated for population subgroups plus inequality arising from differences among subgroup means. This paper derives the class of subgroup decomposable inequality indices that satisfies the Bossert–Pfingsten type intermediate inequality invariance. When the intermediate inequality equivalence concept coincides with the relative notion of inequality, the derived class becomes the Cowell–Shorrocks generalized entropy family. For comments and suggestions, we are grateful to Peter J. Lambert and two anonymous referees. We thank Chranjib Neogi for drawing the only figure of the paper.     

Education policy and inequality: A political economy approach

Regression results show that more unequal societies tend to spend comparatively more on higher levels of education. In a two-period model with heterogeneous agents, this paper investigates the political determinants of this bias. In the first period, public education is financed by the incumbent government by issuing bonds. Investments in basic and higher education have conflicting effects on future labour income distribution and net returns to these investments depend on the tax and transfers system being selected in the following period through the democratic process. Our idea is that public investment in basic education, by decreasing future labour income inequality, may induce future policy-makers to redistribute resources through financial rents taxation, thus making unfeasible the issuing of debt to finance basic education. This will be the more probable the greater wealth inequality is.     

Procedural fairness and the tolerance for income inequality

This paper presents an experiment investigating what cultural and institutional factors underlying a society might render its members more or less tolerant of inequality in favor of greater efficiency. The specific institutional factors we address concern the fairness in the procedures or mechanisms through which individuals believe initial positions or roles in society are determined. Subjects' initial positions (rich vs. poor) are determined based on various criteria (random, meritocratic, arbitrary, and rewarding uncooperative behavior) and individuals' willingness to approve Pareto improvement when the improvement is mainly in favor of the already rich is measured. Our findings show that individuals' willingness to accept higher but more unequal outcomes depends on the source of the initial inequality and random assignment leads to the most tolerance for disadvantageous inequality, generating doubt about commonly held views concerning meritocracy. Moreover, holding the procedures constant, subjects reveal greater tolerance for inequality when self and the opponent share common group identity.     

收入增长与不平等对我国贫困的影响

本文运用两组家计调查数据,采用夏普里(Shaley)分解法实证分析了20世纪90年代收入增长和收入分配的变化在我国贫困变动中的作用,并特别考虑了不同贫困线、贫困指标及等价规模对实证结果的影响。分析结果表明,90年代前半期农村减贫的成功主要归因于收入的增长和不平等的下降。在90年代后半期,农村和城市都经历了不平等的快速上升和收入的缓慢增长。因此,这段时间减贫的速度下降,甚至贫困有所增加。     

Factor decomposition of cross-country income inequality, 1960–1990

In this paper we present Esteban's 1994 [Esteban, J., 1994. La desigualdad interregional en Europa y en España: descripción y análisis. In: Esteban, J.M^a., Vives, X. (dirs.), Crecimiento y convergencia regional en España y en Europa, Vol. 2, Instituto de Análisis Económico] decomposition of the Theil index of inequality over per capita incomes into the (unweighted) sum of the inequality indices of (i) the productivity per employed worker, (ii) the employment rate, (iii) the active over working-age population rate, and (iv) the working-age over total population rate. Each of these factors clearly have different meanings for analysis as well as for policy. We apply this factoral decomposition to a set of 120 countries. We also contrast the empirical findings with the results obtained for the 23 OECD countries. [OECD, Labour Force Statistics, Several issues, Paris].     

An empirical test of the inequality trap concept

The paper uses a GMM estimation to prove the impact of equity on inequality persistence which suggests the presence of inequality trap, and underline the significant influence of the credit market, wealth and education access initial levels.