Stochastic dominance and decomposable measures of inequality and poverty

In this paper, we characterize some new links between stochastic dominance and the measurement of inequality and poverty. We show that: for second-degree normalized stochastic dominance (NSD), the weighted area between the NSD curve of a distribution and that of the equalized distribution is a decomposable inequality measure; for first-degree and second-degree censored stochastic dominance (CSD), the weighted area between the CSD curve of a distribution and that of the zero-poverty distribution is a decomposable poverty measure. These characterizations provide graphical representations for decomposable inequality and poverty measures in the same manner as Lorenz curve does for the Gini index. The extensions of the links to higher degrees of stochastic dominance are also investigated.     

Fuzzy Chronic Poverty: A Proposed Response to Measurement Error for Intertemporal Poverty Measurement

A number of chronic poverty measures are now empirically applied to quantify the prevalence and intensity of chronic poverty, vis‐à‐vis transient experiences, using panel data. Welfare trajectories over time are assessed in order to identify the chronically poor and distinguish them from the non‐poor, or the transiently poor, and assess the extent and intensity of intertemporal poverty. We examine the implications of measurement error in the welfare outcome for some popular discontinuous chronic poverty measures, and propose corrections to these measures that seeks to minimize the consequences of measurement error. The approach is based on a novel criterion for the identification of chronic poverty that draws on fuzzy set theory. We illustrate the empirical relevance of the approach with a panel dataset from rural Ethiopia and some simulations.     

ASPECTS OF POVERTY IN MALAYSIA

This paper is concerned with the definition and measurement of poverty in Malaysia. A poverty line is estimated after considering both the absolute and relative approaches to the definition. Various indices of poverty are discussed, ranging from the simple "incidence of poverty" measure to others which take account of the "poverty gap". There is a derivation of a new index due to Sen, and alternative normalizations are suggested for it. Estimates of all these measures are presented for Malaysia. Finally, the simple "incidence of poverty" measure, which is decomposable, is adopted to construct a "profile" of the poor in Malaysia.     

Vulnerability Orderings for Expected Poverty Indices

Vulnerability to poverty refers to the risk of an individual or household falling below the poverty line. A partial vulnerability to poverty ordering is defined to indicate when a situation characterized by uncertainty means that people are more vulnerable to poverty than in another situation. The family of expected poverty indices used in this context contains versions under vulnerability of many well‐known poverty indices. The ordering resembles the Hardy et al. result on the Lorenz partial ordering. A separate ordering for the expected income gap ratio is also investigated. First‐order stochastic dominance is used to indicate when the expected value of the censored returns from the states increases.     

Challenges in Measuring Poverty and Understanding its Dynamics: A South Asian Perspective

South Asia’s success at reducing poverty does not imply that the topic has become passé. Poverty rates are by now low, but this is because poverty lines are low as well. And the assessment of living standards and their dynamics are blurred by measurement and interpretation challenges. This paper relies mostly on South Asian examples to highlight four tensions: poorer versus richer households, rural versus urban locations, monetary versus non‐monetary dimensions of wellbeing, and household characteristics versus context. The discussion is conducted against the backdrop of the two analytical approaches with South Asian roots that have shaped the debate for decades. This review leads to three main recommendations: household survey data has to be exploited in a more thorough manner, data that is increasingly available from other sources needs to be incorporated more systematically in the analysis, and the multiple dimensions of wellbeing should be better integrated in a common framework.     

Decomposing poverty changes into vertical and horizontal components

Variations in aggregate poverty indices can be due to differences in average poverty intensity, to changes in the welfare distances between those poor of initially unequal welfare status and/or to emerging disparities in welfare among those poor of initially similar welfare status. This note uses a general cost‐of‐inequality approach that decomposes the total change in poverty into a sum of indices of each of these three components. This decomposition can serve inter alia to integrate horizontal and vertical equity criteria in the poverty alleviation assessment of social and economic programmes. The use of these measures is briefly illustrated using Tunisian data.     

“When Life Gives You Lemons”: Using Cross-Sectional Surveys to Identify Chronic Poverty in the Absence of Panel Data

At the core of poverty eradication is the need to eliminate that poverty that is persistent over time (chronic poverty). Unfortunately, traditional approaches to identifying chronic poverty require longitudinal data that is rarely available. In its absence, this paper proposes an alternative approach that only requires 1 year of cross-sectional data on monetary and non-monetary poverty. It puts forth two conjectures and contends that the combined profile of a household as both income poor and multidimensionally poor can be used as a proxy of that household being chronically income poor. To explore the viability of this approach, we use a probit model and longitudinal data for three Latin American countries to estimate households’ probabilities of remaining in income poverty based on their past income and multidimensional poverty statuses. We find empirical support for the approach that is significant, consistent across countries, and robust to various controls and periods of analysis.     

Middle Class,Government Effectiveness and Poverty in the EU: A Dynamic Multilevel Analysis

Using the 2008-2011 EU-Statistics on Income and Living Conditions data, we implement a dynamic three-level model to analyze poverty persistence in 26 EU countries. We isolate true state dependence phenomena by disentangling the effects of observed and unobserved heterogeneity at country level and employ cofactors not previously considered by the literature. Estimates show that unobserved heterogeneity across individuals remains large, even after explicitly controlling for the observable components of individual characteristics. The initial value of poverty has large effects on current poverty status but this effect is not uniform across countries. The risk of poverty is negatively related to the size of the structural middle class and to the level of structural social expenditure but it increases when lagged total public expenditure increases (with respect to the structural value). There is strong evidence of true state dependence.     

中国多维贫困的动态测算、结构分解与精准扶贫

贫困的多维福利剥夺程度高低和持续时间长短是近年来理论界关注的焦点,也是政府制定精准扶贫政策的重要理论依据.文章综合Alkire和Foster(2011)提出的多维贫困测算方法和Foster(2009)提出的长期贫困测算方法,构建了长期多维贫困指数和暂时多维贫困指数,实证分析了中国的贫困状况,并进行了城乡分解、指标分解和区域分解.结果发现:第一,样本家庭在多维视角下的长期贫困比例要高于暂时贫困,这与单一地从收入角度来分析长期贫困和暂时贫困的结论恰好相反;第二,对于所有类型的贫困而言,教育年限、医疗保险和健康的贡献度都排在前三位,但健康对于长期贫困人口的贡献度要明显高于暂时贫困;第三,总体看来,农村的多维贫困程度不仅高于城市,而且很多指标的贫困持续时间也要高于城市;第四,从四大区域看,经济发展水平较低的中西部地区,长期多维贫困程度要高于东部和东北部地区.     

MEASURING POVERTY ACCOUNTING FOR TIME

In this paper we make a methodological proposal to measure poverty accounting for time by proposing a new family of intertemporal poverty indexes that aims at reconciling the way poverty is measured in a static and a dynamic framework. Our index is able to consider the duration of the poverty spell and the social preference for equality in well‐being given that, in contrast with others that have been previously proposed, it is sensitive to the level of inequality between individual complete poverty experiences over time. Moreover, other indices in the literature can be interpreted as special cases of our more general measure. An empirical illustration shows the relevance of considering the distribution of poverty experiences among the population in an international analysis.     

我国农村低收入群体贫困变动及其影响因素——基于福建省农村居民收入分组数据的分析

旨在考察一个较长的时间序列内农村低收入人口贫困状况的动态变化,探明经济增长和收入分配等宏观层面影响因素与贫困指数之间的定量关系与内在联系。基于GQ模型和（模型,选取具备可分解性的FGT指数,采用1990—2006年福建省农村居民收入分组面板数据,分别运用4条低收入标准线对低收入群体的H指数、PG指数、SPG指数和贫困弹性进行模拟。实证结果表明,福建省的经济增长有效减少了绝对低收入人口数量,而收入分配差距的扩大却降低了低收入群体的潜在福利,从而影响农村相对贫困的减少效果。     

FGT Old‐Age Poverty Measures and the Mortality Paradox: Theory and Evidence

Income‐differentiated mortality, by reducing the share of poor persons in the population, leads to the “Mortality Paradox”: the worse the survival conditions of the poor are, the lower is the measured poverty. We show that FGT measures (Foster et al ., 1984 ) are, in general, not robust to variations in survival conditions. Then, following Kanbur and Mukherjee ( 2007 ), we propose to adjust FGT poverty measures by extending the income profiles of the prematurely dead, and we identify the condition under which so‐adjusted FGT measures are robust to mortality changes. Finally, we show, on the basis of data from 2007 on old‐age poverty in 11 European economies, that the effect of extending income profiles of the prematurely dead on poverty measurement varies with: (1) the fictitious income assigned to the prematurely dead; (2) the degree of poverty aversion; (3) the shape of the (unadjusted) income distribution; and (4) the strength of the income/mortality relationship.     

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.     

Using the Consumer Expenditure Survey to Teach Poverty Measurement

Poverty measurement is often controversial, but good public policy relies crucially on a broadly supported and understood poverty measure. In 2010, the U.S. Census Bureau announced it would begin regular reporting of a new supplemental poverty measure in October 2011. The present article provides background information for a student exercise (available, on request, from the author) on alternative poverty measurement techniques. The exercise allows students to use current data from the Consumer Expenditure Survey (available through the Bureau of Labor Statistics at http://www.bls.gov/cex/; U.S. Department of Labor 2010 U.S. Bureau of the Census. 2011. Developing a Supplemental Poverty Measure Federal Register. May 26, Vol. 75, No. 101, http://edocket.access.gpo.gov/2010/pdf/2010-12628.pdf (accessed May 15, 2011) [Google Scholar]) and other sources to calculate and compare several absolute and relative poverty thresholds. The exercise invites students to draw their own conclusions about the pros and cons of different measures, including the new supplemental measure. Data sources are easily updated as new information becomes available.     

The impact of growth and inequality on rural poverty in China

This paper analyzes the evolution of poverty in China from the late 1980s to the late 1990s, employing a version of Shapley decomposition tailored to unit-record household survey data. The changes in poverty trends are attributed to two proximate causes—income growth and shifts in income distribution. Different data sets, poverty lines, poverty measures, and equivalence scales are used to examine the robustness of the results. Potential biases arising from ignoring differential regional prices and inflation are also investigated. Notwithstanding some ambiguities in the results, it is consistently found that rural poverty increased in the second half of the 1990s and adverse distributional changes are the main cause. Journal of Comparative Economics 34 (4) (2006) 694–712.     

Multidimensional Poverty and Material Deprivation with Discrete Data

We propose a characterization of a popular index of multidimensional poverty which, as a special case, generates a measure of material deprivation. This index is the weighted sum of the functioning failures. The important feature of the variables that may be relevant for poverty assessments is that they are discrete in nature. Thus, poverty measures based on continuous variables are not suitable in this setting and the assumption of a discrete domain is mandatory. We apply the measure to European Union member states where the concept of material deprivation was initiated and illustrate how its recommendations differ from those obtained from poverty measures based exclusively on income considerations.     

Profiling the Fuzzy Latent Structure of Multidimensional Poverty: Toward Valuable Insights for Poverty Policymakers

Abstract

Several multidimensional poverty indices have been proposed, and have been extensively studied in the literature. On the other hand, the need for aggregation of poverty indicators into one multidimensional index has been questioned. It has been argued even so that this aggregation can be misleading for political targeting strategies. Subsequently, some researchers have advocated that the use of the latent class analysis would address these issues. However, this setting does not allow to take into account the fuzzy nature of the latent poverty concept. The contribution here is to use the Grade-of-Membership (GoM) model to profile the fuzzy latent structure of multidimensional poverty, for a more realistic handling of this phenomenon. The application of the GoM methodology to multivariate poverty data for the Tunisian case reveals four most prevalent multidimensional poverty profiles. The results emphasize the role played by contextual effects. Indeed, the rural cluster is suffering more intense deprivation and groups in the central and coastal regions have a more comfortable status in comparison with the group of households residing in inland regions. A thorough analysis of these patterns is put forward in this research, giving valuable insights to policy makers.     

Decomposing the contribution of migration to poverty reduction: methodology and application to Tanzania

In an economy with migration, poverty changes are composed of a number of forces, including the income gains and losses realized by the various migration streams. We present a simple but powerful decomposition methodology that uses panel data to measure the contributions of different migration streams to overall poverty change. An application to Tanzania shows the new insights that are provided – in particular on the role of migration to secondary towns in poverty reduction.     

中国贫困的多维测度

本文认为,用单一的收入标准来了解贫困会低估个体真实的贫困状况,很难全面反映个体贫困的复杂性、脆弱性和持久性。本文基于Sen的能力方法,使用中国健康营养调查数据,利用模糊集方法测度中国的多维贫困状况。结论显示,相对于收入贫困,个体的教育、健康和医疗保险等贫困状况更为严重;多维贫困关于测度方法、权重较敏感,等权重下的AF多维贫困被其它方法与权重下的多维贫困严格占优,而在Betti＆Verma权重下的AF多维贫困中,则住房、卫生设施和健康对多维贫困的贡献更大;多维贫困在西部、农村及女性中依然更严重。