EQUIVALENCE SCALE SENSITIVITY OF POVERTY STATISTICS FOR THE MEMBER STATES OF THE EUROPEAN COMMUNITY

Using microdata from Household Budget Surveys of the Member States of the European Community, this paper examines the sensitivity of poverty statistics with respect to the choice of the equivalence scale. The results show that the ranking of the countries with respect to the overall poverty incidence is hardly affected when different equivalence scales are used. However, the composition of the poor population shows considerable changes when e.g. subjective equivalence scales are used instead of the OECD equivalence scale. The poverty incidence among specific household groups, such as single elderly and households with children, is particularly sensitive to the choice of the equivalence scale.     

EQUIVALENCE SCALES, WELL-BEING, INEQUALITY, AND POVERTY: SENSITIVITY ESTIMATES ACROSS TEN COUNTRIES USING THE LUXEMBOURG INCOME STUDY (LIS) DATABASE

The Luxembourg Income Study (LIS) database on which this article is based offers researchers exciting new possibilities for international comparisons based on household income microdata. Among the choices the LIS microdata allows a researcher, e.g. income definition, income accounting unit, etc., is the choice of family equivalence scale, a method for estimating economic well-being by adjusting income for measurable differences in need.
The range of potential equivalence scales that can and are being used in the ten LIS countries and elsewhere to adjust incomes for size and related differences in need span a wide spectrum. The purpose of this paper is to review the available equivalence scales and to test the sensitivity of various income inequality and poverty measures to choice of equivalence scale using the LIS database. The results of our analysis indicate that choice of equivalence scale can sometimes systematically affect absolute and relative levels of poverty; and inequality and therefore rankings of countries (or population subgroups within countries). Because of these sensitivities, one must carefully consider summary statements and policy implications derived from cross-national comparisons of poverty and/or inequality.     

Equity-regarding poverty measures: differences in needs and the role of equivalence scales

Abstract .  The paper investigates the definition of equity-regarding poverty measures when there are different household types in the population. It demonstrates the implications of a between-type regressive transfer principle for poverty measures, for the choice of poverty lines, and for the measurement of living standard. The role of equivalence scales, which are popular in empirical work on poverty measurement, is clarified.     

Eating like which “Joneses?” an Iterative Solution to the Choice of a Poverty Line “Reference Group”

A standard method for calculating poverty lines (e.g. Ravallion, 1994) is not fully specified. The choice of the "reference population" for determining food baskets is left to the decision of the individual analyst. However, the poverty line can be quite sensitive to the real income of the reference group because the "quality" of the food basket—measured as the food expenditures per calorie—rises sharply with income. We propose that the reference group be centered on the poverty line. To address the obvious circularity problem in choosing a reference population at the poverty line to define the poverty line, we use an iterative approach. This iterative method provides a methodological anchor that fixes the reference group.     

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.     

Adjusting for family size in the supplemental poverty measure

We point out an anomaly in the adjustment for family size in the US Supplemental Poverty Measure (SPM). The equivalence scale for the SPM implies an instance of increasing marginal costs for an additional adult. A similar criticism of the official US poverty measure was one of several concerns that led to the creation of the SPM. We propose two possible solutions for the problem and show that eliminating the anomaly from the SPM has the greatest effect on the poverty rate for the elderly, as that group is more concentrated near the poverty line.     

RELATIVE INEQUALITY AND POVERTY IN GERMANY AND THE UNITED STATES USING ALTERNATIVE EQUIVALENCE SCALES

We use data from the Luxembourg Income Study to show the sensitivity of measures of relative economic well-being of persons in the U.S. and Germany using official equivalence scales and consumption-based country-specific equivalence scales developed for the two countries. Overall inequality and poverty levels are found not to be sensitive to the equivalence scale used. However, the official German equivalence scale yields quite different results from the others with respect to the relative income and poverty levels of vulnerable groups within the population, especially older single people.     

Decomposing Vulnerability to Poverty

This paper applies the decomposition of the Foster–Greer–Thorbecke poverty index to the measurement of individual vulnerability to poverty. I highlight that poverty risk can be expressed as a function of expected incidence, expected intensity, and expected variability below the poverty line, three essential aspects for improving the design of appropriate risk‐management policies. An empirical illustration is provided using the British Household Panel Survey and the Italian Survey on Household Income and Wealth.     

Measuring lifetime poverty

This paper presents an axiomatic framework for measuring lifetime poverty over multiple periods. For an individual, we argue that lifetime poverty is influenced by both the “snapshot” poverty of each period and the poverty level of the “permanent” lifetime consumption; it is also influenced by how poverty spells are distributed over the lifetime. We axiomatically characterize classes of lifetime poverty indices and derive dominance conditions of poverty orderings for both individual and societal lifetime poverty measurements.     

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.     

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.     

THE IMPORTANCE OF CONSECUTIVE SPELLS OF POVERTY: A PATH‐DEPENDENT INDEX OF LONGITUDINAL POVERTY

In this paper we propose a new index of individual poverty in the longitudinal perspective, taking into account the way poverty and non‐poverty spells follow one another along individual life courses. The Poverty Persistence Index (PPI) is based on all the pairwise distances between the waves of poverty. The PPI is normalized and it assigns a higher degree of (longitudinal) poverty to people who experience poverty in consecutive, rather than separated, periods, for whom the distances from the poverty line are larger along time and moreover, when the worst years are consecutive and/or recent. We also propose an aggregate index of persistence in poverty (APPI) in order to measure the distribution of the persistence of poverty in a society, and evaluate at once the diffusion of poverty, its depth, duration, and recentness. The indices are tested in comparison with other measures from the literature both at the individual as well as at the societal level.     

A new fuzzy unidimensional poverty index from an information theory perspective

This article proposes to use an information theory approach to design a fuzzy unidimensional poverty index. In order to avoid the usual binary definition of poverty, a fuzzy set approach has been used. The total population is partitioned into three mutually exclusive groups around the poverty line. This builds on fuzzy set theory whereby the definition of the threshold of who is poor or non-poor is fuzzy. This article proposes a method using a membership function and a confidence interval of poverty line to identify to what extent households can be considered as poor or non-poor. According to this membership function, a relative entropy measure is adopted to assess an aggregation method of fuzzy individual poverty. An application using individual well-being data from Tunisian households is presented.     

THE NON-CONSTANCY OF EQUIVALENCE SCALES

Comparisons of households of differing composition are usually achieved through the use of equivalence scales. It is well known that the choice of scales can have considerable impact on the conclusions drawn from studies of welfare and poverty. There is a considerable literature on the theoretical issues relating to equivalence scales, but applied work on income distribution and related areas almost invariably takes scales to be constant irrespective of income. This paper focuses on the relation of scale to income, by applying theoretical analysis to some simple household types. The conclusion is that scales are not constant and that current practice should be changed.     

A stochastic dominance approach to the measurement of discrimination

This note suggests a bridge between stochastic dominance (Rothschild and Stiglitz, 1970 [17], 1973 [18]), inequality measurement (Atkinson, 1970 [1]) and discrimination measurement (Gastwirth, 1975 [10]). Discrimination orderings are defined and illustrated through discrimination curves, in the same spirit as stochastic dominance analysis. The main result, which links the second order discrimination curve and the Gastwirth discrimination index, also generalizes the equivalence between Generalized Lorenz dominance and second order stochastic dominance.     

四省藏区多维贫困空间分异及基层能力建设

四省藏区作为我国深度贫困地区的重要组成部分是精准扶贫精准脱贫中后程的重点和难点。基于2014年采集的“十二五”期间全国“整村推进”项目村基础数据,借鉴A-F多维贫困测度方法,对四省藏区村域多维贫困状况进行测度分解,并基于拓展的能力视角探讨了村级组织能力禀赋对四省藏区村域多维贫困状况的差异化缓解作用。结果发现:除经济贫困之外,四省藏区还遭受基础教育和生产生活条件等维度的多维贫困,且存在空间异质性,云南和青海藏区是四省藏区中多维贫困问题最严重的区域;生活水平条件和村域发展资本维度对四省藏区的多维贫困指数贡献率最高;基层组织能力禀赋会显著影响四省藏区村域的多维贫困状况、缩小地区差距,在深度贫困地区更加显著。根据研究结论,从覆盖基础教育设施、改善生产生活条件、提高基层组织能力建设三方面为深度贫困地区脱贫攻坚提供政策参考。     

A SYNTHESIS OF POVERTY LINE DEFINITIONS*

A fundamental point of discussion in poverty research is whether poverty is an absolute or a relative concept. If poverty is seen to be a situation of absolute deprivation, a poverty line will usually be defined to be independent of the general style of living in society. If poverty is considered to be a situation of relative deprivation, a poverty line will be defined in relation to the general style of living in society. The choice for one of these two approaches has important consequences for social policy, as absolute poverty may be reduced by economic growth, while relative poverty will only decrease when income inequality decreases. This paper suggests a poverty line definition that is not a priori meant to be either absolute or relative, but depends on the perception of poverty in society. If the poverty line is higher in countries with higher median income (as an indicator of “general style of living”) the poverty line is said to be relative; if the poverty line does not vary with median income, it is said to be absolute. The poverty line definition suggested appears to be a generalization of almost all well-known poverty line definitions. Poverty lines thus defined are estimated for eight European countries on the basis of a 1979 survey. The resulting lines appear to have an elasticity with respect to median income of 0.51, and hence can be said to be halfway on the scale between absolute and relative.     

HOUSEHOLD NEEDS AND POVERTY: WITH APPLICATION TO SPAIN AND THE U.K.

We examine the sensitivity of U.K.-Spanish poverty comparisons to variations in the dependence of equivalence scales on household size and composition, using evidence from national household budget surveys. We sum up these comparisons using subjective confidence levels. Taking into account the dissimilarities in the distribution of incomes and needs across countries, we find, inter alia , that although the poor are typically more numerous in Spain than in Britain, the actual headcount differences may vary by up to 10 percent of the population when needs allowances are altered, even when kept the same across the two countries. Comparisons of poverty composition across the two countries are also very sensitive to the choice of equivalence scale parameters. Generally, however, the proportion of single adults among the poor is much less important in Spain than in Britain, the reverse being true for households with three or more adults.     

POVERTY IN POLAND DURING THE 1990s: ARE THE RESULTS ROBUST?

This study examines the robustness of poverty measures for Poland in the 1990s to employed methods. At least two definitions or techniques of estimation are applied to each of the following components of poverty measures: (1) household well-being; (2) poverty line; (3) equivalence scales; and (4) poverty index. Furthermore, groups at risk of poverty are selected by means of decomposition of the poverty incidence and by estimation of the probit model. Relatively robust conclusions can be reached for trends in absolute poverty incidence, which show an inverted U-shape with rapidly increasing poverty rates in 1993–1995 and declining rates since, but with continued increases in relative poverty. Some robust correlates of high poverty (low education, unemployment, rural residence, large number of children) are also found.     

MEASUREMENT OF POVERTY: POLAND IN THE 1980s

This paper presents results of an examination of poverty in Poland in the 1980s. The individual welfare measure is expenditure on consumption per equivalent adult. Household equivalence scales are estimated using a quasi-exact scales trans logarithmic model. Four poverty indices are calculated. These are intended to capture the following aspects of poverty: (1) incidence, (2) relative deprivation, acid (3) social ability to eliminate poverty by income transfers. The study revealed significant changes in poverty during the investigated period, from 9 to 30 percent with persistent poverty resulting for pensioners, farmers and low educated persons.