A Consistent Poverty Approach to Assessing the Sensitivity of Income Poverty Measures and Trends

This paper examines the sensitivity of estimates of income poverty rates and trends to variations in the poverty line and to whether or not certain households are included or excluded from the sample used to estimate poverty. The approach draws on the concept of consistent poverty, which has been used to identify those with incomes below the poverty line who also experience deprivation. Our approach involves excluding households with incomes below the poverty line if they report zero or negative income or are self‐employed, have expenditure well in excess of their income, have substantial wealth holdings, or if they do not report having experienced financial stress over the past year. The combined impact of all four exclusions is to reduce the half‐median income poverty rate from 9.9 per cent to 5.4 per cent, but also suggests that poverty increased by more over the decade to 2003–04 than the original estimates indicate.     

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.     

Mapping the Australian Poverty Profile: A Multidimensional Deprivation Approach

The limitations of income‐based poverty lines are widely acknowledged, but Australia lags behind many other countries in implementing new measures of social disadvantage based on the deprivation approach. A new suite of questions included in wave 14 of the Household, Income and Labour Dynamics in Australia (HILDA) survey allows the deprivation approach to be applied. This article describes the advantages of the deprivation approach and shows that while the income and deprivation approaches can produce similar overall results, the circumstances of some sub‐groups vary greatly according to which measure is used. A measure based on deprivation alone and/or a combined measure would be an important complement to conventional income‐based poverty rates.     

THE SIZE AND DISTRIBUTION OF THE POVERTY GAP IN CANADA: A MICRO ANALYSIS OF VARIATIONS AMONG DEMOGRAPHIC GROUPS

Poverty is a much used term by politicians, economists, sociologists, the media and interest groups. Although there is some common consensus that the word poverty means some type of deprivation, there is a lack of comprehensive measures to quantify this term. Although deprivation can relate to a number of areas such as health and education, the focus in policy development has been aimed at economic deprivation or more specifically, income adequacy. Even in this perspective, the availability of comprehensive measures are limited. The United States is the only major industrial nation that has an official poverty line. Several unofficial poverty lines have been developed in Canada, but the poverty measures have not gone beyond head counts of people who fall below these lines. In an environment where the goal is to further progressive social development constrained by inadequate public resources, the emphasis has been on first directing scarce resources to those "most in need". To get a better perception of economic need, this paper provides a micro analysis of the size and distribution of the poverty gap so that meaningful comparisons can be made between demographic groups. The results of this analysis yield some interesting findings. For example, there are virtually no poor elderly couples and although there are a large number of poor single elderly, their income shortfalls are relatively small and are highly concentrated near the poverty line; the poverty rate among families with children is quite low but their incomes on average fall well below the poverty line and are widely dispersed; and single parents fare badly on all measures.     

Persistent and Consistent Poverty in the 1994 and 1995 Waves of the European Community Household Panel Survey

This paper focuses on the mismatch between income and deprivation measures of poverty. Using the first two waves of the European Community Household Panel Survey, a measure of relative deprivation is constructed and the overlap between the relative income poor and relatively deprived is examined. There is very limited overlap with the lowest relative income threshold. The overlap increases as the income threshold is raised, but it remains true that less than half those below the 60 percent relative income line are among the most deprived. Relative deprivation is shown to be related to the persistence of income poverty, but also to a range of other resource and need factors. Income and deprivation measures each contain information that can profitably be employed to enhance our understanding of poverty and a range of other social phenomena. This is illustrated by the manner in which both income poverty and relative deprivation are associated with self-reported difficulty making ends meet.     

VALUE JUDGEMENTS IMPLIED BY THE USE OF VARIOUS MEASURES OF INCOME INEQUALITY*

If a welfare economist wants to express income inequality in a sensible way by a single parameter, he has to make rather strong assumptions regarding the social preferences of his fellow citizens. Formulas are presented with whose aid one is able to test whether or not these assumptions hold. The standard measures used nowadays contradict prevailing preferences. If no common single measure can be found which fits the social preferences of almost all individuals concerned tolerably well, additional parameters measuring poverty and riches separately are necessary.     

Bivariate income distributions for assessing inequality and poverty under dependent samples

As indicators of social welfare, the incidence of inequality and poverty is of ongoing concern to policy makers and researchers alike. Of particular interest are the changes in inequality and poverty over time, which are typically assessed through the estimation of income distributions. From this, income inequality and poverty measures, along with their differences and standard errors, can be derived and compared. With panel data becoming more frequently used to make such comparisons, traditional methods which treat income distributions from different years independently and estimate them on a univariate basis, fail to capture the dependence inherent in a sample taken from a panel study. Consequently, parameter estimates are likely to be less efficient, and the standard errors for between-year differences in various inequality and poverty measures will be incorrect. This paper addresses the issue of sample dependence by suggesting a number of bivariate distributions, with Singh–Maddala or Dagum marginals, for a partially dependent sample of household income for two years. Specifically, the distributions considered are the bivariate Singh–Maddala distribution, proposed by Takahasi (1965), and bivariate distributions belonging to the copula class of multivariate distributions, which are an increasingly popular approach to modelling joint distributions. Each bivariate income distribution is estimated via full information maximum likelihood using data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey for 2001 and 2005. Parameter estimates for each bivariate income distribution are used to obtain values for mean income and modal income, the Gini inequality coefficient and the headcount ratio poverty measure, along with their differences, enabling the assessment of changes in such measures over time. In addition, the standard errors of each summary measure and their differences, which are of particular interest in this analysis, are calculated using the delta method.     

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.     

Calculating Poverty Measures from the Generalised Beta Income Distribution

Data for measuring poverty are frequently available in a summary form that describes the proportion of income or expenditure for each of a number of population proportions. While various discrete poverty measures can be applied directly to data in this limited form, they typically require an arbitrary approach to within‐group interpolation. This problem can be overcome by fitting either a parametric income distribution or a Lorenz curve to the grouped data and computing the required quantities from estimated parameters. The Lorenz curve approach is widely used by the World Bank, but can encounter problems. As an alternative, in this article we show how to calculate several poverty measures from parameters of the generalized beta income distribution, and its popular special cases. An analysis of poverty changes in countries from South and Southeast Asia is used to illustrate the methodology.     

POVERTY COMPARISONS WITH ABSOLUTE POVERTY LINES ESTIMATED FROM SURVEY DATA

The objective of measuring poverty is usually to make comparisons over time or between two or more groups. Common statistical inference methods are used to determine whether an apparent difference in measured poverty is statistically significant. Studies of relative poverty have long recognized that when the poverty line is calculated from sample survey data, both the variance of the poverty line and the variance of the welfare metric contribute to the variance of the poverty estimate. In contrast, studies using absolute poverty lines have ignored the poverty line variance, even when the poverty lines are estimated from sample survey data. Including the poverty line variance could either reduce or increase the precision of poverty estimates, depending on the specific characteristics of the data. This paper presents a general procedure for estimating the standard error of poverty measures when the poverty line is estimated from survey data. Based on bootstrap methods, the approach can be used for a wide range of poverty measures and methods for estimating poverty lines. The method is applied to recent household survey data from Mozambique. When the sampling variance of the poverty line is taken into account, the estimated standard errors of Foster–Greer–Thorbecke and Watts poverty measures increase by 15–30 percent at the national level, with considerable variability at lower levels of aggregation.     

THE SENSITIVITY OF INTERNATIONAL POVERTY COMPARISONS

Using data from the Luxembourg Income Study, I study the sensitivity of cross-national income poverty comparisons to the method in which poverty is measured. Absolute poverty comparisons that keep the purchasing power at the poverty line constant across countries lead to conclusions that differ from relative poverty comparisons in which the real value of the poverty line varies with average income. The absolute poverty ranking of countries also varies as the real value of the poverty line is lowered. Cross-national differences in household characteristics are largely irrelevant in explaining poverty differences.     

Fuel poverty and access to electricity: comparing households when they differ in needs

Although sequential stochastic dominance techniques have been used in the literature to make comparisons of income poverty which are robust to the assumptions made about the economies of scale within households, the techniques could be applied to a much wider set of issues. In this paper, these techniques are applied to energy deprivation in Guatemala. Fuel poverty is compared among households with and without access to electricity, and it is assessed whether access to electricity for those who do not have access currently would eliminate the observed difference in fuel poverty between the two groups of households.     

Individual needs and social pressure: Evidence on the Easterlin hypothesis using repeated cross-section surveys of Canadian households

This paper provides additional evidence, using time-series and cross-sectional Canadian survey data, for the Easterlin hypothesis of an important income elasticity of individual needs. Our analysis is based on the regression of a minimum income to satisfy needs equation derived from a simple utility maximization framework. Moreover, our specification allows computing the Arrow-Pratt relative risk-aversion index and the Intertemporal Rate of Substitution. Our results are robust to different estimation methods dealing with the endogenous nature of income. We also compute poverty rates using our estimated equation parameters and standard OECD measures of poverty and find that some subjective measures are relatively close to the OECD measures.     

THE EFFECT ON POVERTY STATUS IN ISRAEL OF CONSIDERING WEALTH AND VARIABILITY OF INCOME

This paper assesses the effects of including wealth and the variability of income on the incidence of poverty and the degree of income inequality in Israel. A special survey, which includes data on the wealth and income of a national sample of Israeli families in 1963–64 and 1964–65, allows us to go beyond measures based on current income alone.
The first section reviews earlier studies of poverty in Israel. The next section looks at poverty and inequality in terms of current income, current wealth, and a combined measure of income and wealth. The combined measure is the Hansen-Weisbrod measure (HW), which equals income plus the annuity value of wealth, assuming all wealth is just consumed at the time of death. It is interesting that, in spite of the much higher wealth inequality than income inequality, the HW measure was slightly more equally distributed than income. This result occurred because the annuity component made up a low share of the total HW measure and the correlation between income and wealth was well under 1. Although overall inequality and poverty were similar for income and HW measures, the incidence of poverty by subgroup depended on the measure used.
The final section presents a dynamic view of poverty and inequality. Year-to-year changes in poverty were substantial. Because of the use of a relative poverty concept and the rise in real incomes, the real income poverty line rose by 15 percent between 1963 and 1964. Still, of those in income poverty in 1963, 37 percent managed to escape poverty in 1964. The paper shows how the degree to which poverty was stable or transitory varied substantially by age and country of origin.     

Poverty as social deprivation: a survey

The concept of poverty is discussed using qualitative and quantitative measures as an indicator for social deprivation. Poverty can be absolute, relative, income based, consumption based, or entitlement based. The variation in the concept of poverty reveals its dimensionality. However, when closely examined, these dimensions are seen to be conceptually interrelated and complementary rather than substitutable. The concept used to define poverty determines the methods employed to measure it. Composite indicators can hide important policy messages inherent in their constituent variables.     

INCOME POVERTY AND MULTIDIMENSIONAL DEPRIVATION: LESSONS FROM CROSS‐REGIONAL ANALYSIS

The study of multidimensional deprivation has become one of the most relevant lines of research in the analysis of low‐income households. The search for significant relationships between multidimensional deprivation and income poverty has been a central issue and most empirical studies have found a very weak link. This paper aims at examining the possibility of an aggregation bias in national‐level studies, which could conceal disparities between regions. As regional differences and decentralization processes stand out in Spain as compared to other OECD countries, we focus the analysis on this country. Latent class models are used to define deprivation indices using the Spanish EU‐SILC. The results seem to show that the absence of significant relationships between both phenomena still holds at a regional level. The decomposition methods used in the paper show that it might be due to some regional singularities in some determining factors of income and multidimensional poverty.     

Living Decently

One of the reasons why poverty lines became popular at the turn of the century was their promise of a scientific technique that would dispense with moralising about poverty. We argue that a price paid in this quest has been an impoverishment of the richness of the notion of 'a decent life', the moral concept underlying poverty. In addition, poverty lines have in practice been more to do with inequality at the bottom end of the income distribution than with poverty. The purpose of this article is to rehabilitate the measurement of poverty, and to make it credible. We set out our preferred method of poverty measurement, and illustrate it using data from the Australian Standard of Living Study. A feature of our approach is to distinguish clearly between issues of inequality and issues of poverty. Questions such as who is on the bottom of the income distribution, whether this has changed over time, and how income levels of the worst off compare with the mean, are questions of inequality. As such, the answers tell us nothing at all about how the worst off are actually living. To answer that question, we require direct measures of consumption and of social participation. These measures are not as simple, but they provide us with knowledge about poverty that poverty lines have promised, but have not delivered in a credible fashion.     

Absolute and Relative Deprivation and the Measurement of Poverty

This paper develops the link between poverty and inequality by focussing on a class of poverty indices (some of them well–known) which aggregate normative concerns for absolute and relative deprivation. The indices are distinguished by a parameter value that captures the ethical sensitivity of poverty measurement to "exclusion" or "relative–deprivation" aversion. The indices can be readily used to predict the impact of growth on poverty. An illustration using LIS data finds that the United States show more relative deprivation than Denmark and Belgium whatever the percentiles considered, but that overall deprivation comparisons of the four countries considered will generally depend on the intensity of the ethical concern for relative deprivation. The impact of growth on poverty also depends on the presence of and on the attention granted to concerns over relative deprivation.     

A NON‐PARAMETRIC MEASURE OF POVERTY ELASTICITY

We estimate the growth elasticity of poverty (GEP) using recently developed non‐parametric panel methods and the most up‐to‐date and extensive poverty data from the World Bank, which exceeds 500 observations in size and represents more than 96 percent of the developing world's population. Unlike previous studies which rely on parametric models, we employ a non‐parametric approach which captures the non‐linearity in the relationship between growth, inequality, and poverty. We find that the growth elasticity of poverty is higher for countries with fairly equal income distributions, and declines in nations with greater income disparities. Moreover, when controlling for differences in estimation technique, we find that the reported values of the GEP in the literature (based on the World Bank's now‐defunct 1993‐PPP based poverty data) are systematically larger in magnitude than estimates based on the latest 2005‐PPP based data.