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Revision , June 20 12. The Irish Deprivation Measures Conceptual Underpinnings. The Purpose of Composite Deprivation Indices. It is difficult to simultaneously comprehend the spatial distribution of multiple indicators at multiple points in time
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Revision, June 2012 The Irish Deprivation MeasuresConceptual Underpinnings
The Purpose of Composite Deprivation Indices It is difficult to simultaneously comprehend the spatial distribution of multiple indicators at multiple points in time For practical purposes, there is a need for a single indicator which draws a variety of observations together Such indices can provide the basis for the effective targeting of the most disadvantaged areas Such indices can provide a means by which to assess changes over time, and facilitate monitoring and evaluation However, it is important that such indices enjoy broad support amongst all key stakeholders, including government departments, state agencies, community representatives and the broader public
A Comprehensive Definition of Poverty • Relative Poverty “People are living in poverty if their income and resources (material, cultural and social) are so inadequate as to preclude them from having a standard of living which is regarded as acceptable by Irish society generally.” (Government of Ireland, NAPS, 1997) • Relative Deprivation “The fundamental implication of the term deprivation is of an absence – of essential or desirable attributes, possessions and opportunities which are considered no more than the minimum by that society.” (Coombes et al., DoE – UK, 1995)
Traditional Approach: Exploratory Factor Analysis (EFA) • Ordinary Factor Analysis (EFA) reduces variables to a smaller number of underlying Dimensions or Factors V1 F1 V2 V3 V4 V5 F2 V6 • EFA is essentially an exploratory technique; .i.e. data-driven • all variables load on all factors • the structure matrix is the (accidental) outcome of the variables available • EFA does not account for measurement error (v1-v6 are assumed to be perfect indicators) • EFA can not be used to compare outcomes over time
New Approach: Confirmatory Factor Analysis (CFA) • Confirmatory Factor Analysis also reduces observations to the underlying Factors, however • variables are conceptualised as the (imperfect) manifestations of underlying or latent concepts d V1 1 L1 d V2 2 d V3 3 d V4 4 d V5 L2 5 d V6 6 • CFA requires a strong theoretical justification before the model is specified • the researcher decides which of the observed variables are to be associated with which of the latent constructs • variables are assumed to be imperfect manifestations (i.e. allowing for measurement error) • CFA model allows the comparison of outcomes over time • CFA facilitates the objective evaluation of the quality of the model through fit statistics
The Underlying Dimensions of Social Disadvantage • Demographic Decline(predominantly rural) • population loss and the social and demographic effects of emigration (age dependency, low education of adult population) • Social Class Deprivation(applying in rural and urban areas) • social class composition, education, housing quality • Labour Market Deprivation(predominantly urban) • unemployment, lone parents, low skills base
The Basic Model of Affluence and Deprivation d Age Dependency Rate 1 Demographic d Population Change Growth 2 d Primary Education only 3 d Third Level Education 4 d Professional Classes Social Class 5 Composition d Persons per Room 6 d Lone Parents 7 d Semi- and Unskilled Classes 8 Labour Market d Male Unemployment Rate Situation 9 d Female Unemployment Rate 10
Dynamic Path Diagram for 1991, 1996, 2002 and 2006 Initial Growth Rapid Growth Slow-Down There is only a small correlation between the urban and rural components of the index. This confirms the theoretical underpinning of the model which stipulates that urban and rural disadvantage are conceptually different and that the unemployment rate, for example, is not a useful indicator of rural deprivation.
Change in Absolute Deprivation Scores, 1991-2006 The figure shows the unprecedented growth in Ireland over the past 15 years, with greatest changes occurring in the 1996 to 2002 period. • 1991 – 1996: increase in mean scores of 2.4 • 1996 – 2002: increase in mean scores of 5.8 (8.2 cumulatively) • 2002 – 2006: increase in mean scores of 0.7 (8.9 cumulatively)
Change in Centred Deprivation Scores, 1991-2006 The figure shows the distribution of deprivation scores after ‘detrending’ the data; i.e. subtracting the average national growth in affluence. The main observation is the gradual narrowing of the distribution over time. This, however, has to be interpreted in the context of a substantial decline in deprivation. As the measurements for each indicator slide down the scale, during this period of rapid growth, the observations tend to cluster more narrowly around the mean.
Change in Relative Deprivation Scores, 1991-2006 The figure shows the final distribution of Relative Deprivation Scores, after controlling for the underlying trend and standardising its spread. The scores thus look at deprivation at each point in time; i.e. as it might be perceived in relative terms.
Overlay of Paired Relative Index Scores, 1991-2006
Mapping Deprivation most disadvantaged most affluent
Absolute Affluence and Deprivation 1991 - 2006 1991 1996 2006 2002
Comparison of Absolute Deprivation Scores, 1991-2006 • Shows how affluence has grown throughout the whole country. • Greatest change occurred between 1996 and 2002. • Shows how affluence has grown in concentric rings around the main urban centres, effectively demarcating the urban commuter belts. • Shows that, with the exception of Dublin Inner City, cities in general have not improved in their affluence as much as the rest of the country.
Relative Affluence and Deprivation 1991 - 2006 1991 1996 2006 2002
Comparison of Relative Deprivation Scores, 1991-2006 • Apart from Dublin Inner City, where there is evidence of substantial gentrification, there are little differences in Relative Deprivation Scores between 1991 and 2006, representing random noise only.
Strengths of CFA-based Deprivation Indices • true multidimensionality, based on theoretical considerations • provides for a balanced approach between urban and rural deprivation • no double-counting • rational choice to indicator selection • uses variety of alternative fit indices to test model adequacy • identical structure matrix across multiple waves • identical measurement scale across multiple waves • true distances to means are maintained (i.e. measurement, not ranking) • distinguishes between measurement of absolute and relative deprivation • allows for true inter-temporal comparisons
Towards an All-ISland Deprivation Index For the Island of Ireland (Overview) • Brief History of Deprivation Indices North and South • New Census Geographies • The Need for consistent All-Island Data • The 2011 Census • A feasible Methodology
Deprivation Indices North and South • Northern Ireland • 1981 – Urban Priority Areas (Department of the Environment-UK, 1983) • 1991 – Relative Deprivation in NI (Robson et al., 1994) • 2001 – NI Multiple Deprivation Measures (Noble, 2001) • 2005 – NIMDM update (NISRA, 2005) • 2010 – NIMDM update (NISRA, 2010) • Republic of Ireland • 1991 – Index of Relative Affluence and Deprivation (Haase et al., 1996) • 1996 – Index of Relative Affluence and Deprivation (Pratschke & Haase, 2000) • 2002 – Index of Relative Affluence and Deprivation (Haase & Pratschke, 2005) • 2006 – New Measures of Deprivation (Haase & Pratschke, 2008) • 2006 – Pobal-Haase Deprivation Index (Haase & Pratschke, 2010)
New Census Geographies • Northern Ireland • Census Output Areas (OA), as of 2001 • Super Output Areas (SOA), as of 2001 • Republic of Ireland • Atomic Small Areas (SA), as of 2006 • need to derive SOA equivalents
The Need for Consistent All-ISland Data • to facilitate Cross-Border Initiatives • PEACE III • INTERREG IV • IFI • administratively • CSO / NISRA co-operation • AIRO / ICLRD • INIsPHO
The 2011 Census • Close match of Data for Ireland, North and South • 2011 Census provides European-wide comparable data • The need for new measures of regional disparity at European level
Methodological Challenges (Overview) • Comparability of Indicator Variables • Temporal Synchronicity • Common Dimensionality of Deprivation • Common Statistical Model • Standardisation of Index Scores across Multiple Jurisdictions
Comparability of Indicator Variables • Comparable Indicator Variables • Population Change • Age Dependency • Lone Parents Ratio • Male Unemployment Rate • Female Unemployment Rate • Average Number of Persons per Room • Significantly Varying Indicator Variables • Proportion of Adult Population with Primary Education Only • Proportion of Adult Population with Third Level Education • Proportion of Population in Higher and Lower Professional Classes • Proportion of Population in Semi- and Unskilled Manual Classes
Temporal Syncronicity • NI data relates to 2001 Census • RoI data relates to 2006 Census • This is not a huge problem. As the inter-temporal analysis of deprivation across four census waves for the RoI has shown, relative deprivation does not significantly change over time. • The present analysis is intended to be first and foremost a ‘proof of concept’. Its real significance lies in being applied with respect to the 2011 Census.
Common Dimensionality of Deprivation v3 Age Dependency Rate d 3 d v2 Population Change Demographic 2 Decline v5 Primary Education Only d 5 d v6 Third Level Education 6 d v11 Persons per Room Social Class 11 Disadvantage d v7 Professional Classes 7 d v8 Semi/Unskilled Classes 8 d v4 Lone Parents Labour Market 4 Deprivation d v9 Male Unemployment 9 d v10 Female Unemployment 10
Standardisation of Index Scores across Multiple Jurisdictions • Joint standardisation of all factor scores • Simple additive approach to combining factors scores • Resulting in comparable deprivation scores North and South, based on an identical factor structure.
How to Judge a Good Deprivation Index • Back to the purpose of deprivation indices, i.e. their ability to • facilitate the simultaneous comprehension of multiple indicators. • to provide the basis for the effective targeting of the most disadvantaged areas. • to provide a means by which to compare performance between regions, assess change over time, and facilitate monitoring and evaluation. • enjoy broad support amongst all key stakeholders, including government departments, state agencies and community representatives. • By way of cross-referencing deprivation scores with a multitude of key social, economic, health and other outcomes which are known to have an SES gradient.