The 2011 Pobal HP Deprivation Index for Small Areas (SA) Statistical Features Dublin, August 2012
Introduction to The 2011 Pobal HP Deprivation Index This presentation highlights some of the more technical issues in the construction of the 2006 and 2011 Pobal HP Deprivation Index for Small Areas (SA) and is aimed at the more statistically-minded reader. At the level of the individual indicator variables, the presentation includes: The transformation of the 2006 indicator variables The transformation of the 2011 indicator variables A comparison of the 2006 and 2011 indicator variables At the level of the new Pobal HP Deprivation Index, the presentation includes: The change in the 2006-2011 Absolute Index Scores The change in the 2006-2011 Relative Index Scores
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
Pobal HP Deprivation Index Basic Model of the Pobal HP Deprivation Index d Age Dependency Rate 1 Demographic d Population Change Growth 2 d Primary Education only 3 d Third Level Education 4 d Persons per Room 5 Social Class Composition d Professional Classes 6 d Semi- and Unskilled Classes 7 d Lone Parents 8 Labour Market d Male Unemployment Rate Situation 9 d Female Unemployment Rate 10
The Transformation of Indicator Variables When deriving composite indicators for multi-dimensional concepts, like deprivation, it is common practice to transform the individual indicator variables to normalise their distribution prior to model estimation The most common transformations include: truncation - to avoid the undue influence of extreme outliers zero-centering – to eliminate unwanted trend influences logarithmic – to normalise a skewed distribution The transformation of scaled variables does not affect the order of observations The overall emphasis on deriving true measures for the composite index as a distance from the mean is thereby maintained, whilst avoiding that this is unduly influenced by a small number of extreme observations
Population change (SA) Transformation: truncated at ±60% 2006 Before Mean: 12.0 STD: 29.1 Skew: 4.3 Kurtosis: 34.9 After Mean: 9.9 STD: 20.1 Skew: 1.3 Kurtosis: .8 2011 Before Mean: 48.9 STD: 645.8 Skew: 34.8 Kurtosis: 1527 After Mean: 7.6 STD: 21.2 Skew: 1.0 Kurtosis: 1.0 Comparison of 2006 and 2011 r = 0.39 n = 18,246
Age dependency Rate (SA) Transformation: truncated at 70% 2006 Before Mean: 31.1 STD: 8.8 Skew: -0.35 Kurtosis: 3.0 After Mean: 31.1 STD: 8.7 Skew: -0.55 Kurtosis: 1.6 2011 Before Mean: 32.7 STD: 8.2 Skew: -0.71 Kurtosis: 1.9 After Mean: 32.7 STD: 8.2 Skew: -0.72 Kurtosis: 1.8 Comparison of 2006 and 2011 r = 0.75 n = 18,246
Lone Parent Rate (SA) Transformation: natural log 2006 Before Mean: 20.9 STD: 17.5 Skew: 1.3 Kurtosis: 1.8 After Mean: 3.3 STD: .54 Skew: 0.07 Kurtosis: -0.6 2011 Before Mean: 21.5 STD: 16.5 Skew: 1.2 Kurtosis: 1.4 After Mean: 3.3 STD: 0.51 Skew: 0.01 Kurtosis: -0.5 Comparison of 2006 and 2011 r = 0.61 n = 18,246
Primary Education Only (SA) Transformation: zero-centred – natural log 2006 Before Mean: 18.7 STD: 12.1 Skew: 0.7 Kurtosis: 0.7 After Mean: 3.6 STD: 0.3 Skew: 0.02 Kurtosis: -0.7 2011 Before Mean: 16.0 STD: 10.7 Skew: 0.8 Kurtosis: 0.5 After Mean: 3.7 STD: 0.3 Skew: 0.2 Kurtosis: -0.6 Comparison of 2006 and 2011 r = 0.90 n = 18,246
Third Level Education (SA) Transformation: zero-centred – natural log 2006 Before Mean: 30.9 STD: 16.8 Skew: 0.9 Kurtosis: 0.4 After Mean: 3.6 STD: 0.4 Skew: -0.17 Kurtosis: -0.14 2011 Before Mean: 30.7 STD: 16.6 Skew: -0.85 Kurtosis: 0.47 After Mean: 3.6 STD: 0.4 Skew: -0.20 Kurtosis: -0.12 Comparison of 2006 and 2011 r = 0.90 n = 18,246
Higher and Lower Professionals (SA) Transformation: none 2006 Before Mean: 32.9 STD: 15.0 Skew: 0.4 Kurtosis: -0.04 After Mean: STD: Skew: Kurtosis: 2011 Before Mean: 34.1 STD: 15.2 Skew: 0.4 Kurtosis: -0.14 Comparison of 2006 and 2011 r = 0.89 n = 18,246
Semi- and Unskilled Social Classes (SA) Transformation: natural log 2006 Before Mean: 19.4 STD: 10.6 Skew: 0.8 Kurtosis: 1.2 After Mean: 3.2 STD: 0.4 Skew: -0.3 Kurtosis: 0.0 2011 Before Mean: 18.6 STD: 9.8 Skew: 0.7 Kurtosis: 0.5 After Mean: 3.2 STD: 0.4 Skew: -0.3 Kurtosis: -0.1 Comparison of 2006 and 2011 r = 0.81 n = 18,246
Male Unemployment rate (SA) Transformation: natural log 2006 Before Mean: 9.1 STD: 8.4 Skew: 2.4 Kurtosis: 11.0 After Mean: 2.3 STD: 0.6 Skew: 0.2 Kurtosis: -0.1 2011 Before Mean: 23.1 STD: 12.7 Skew: 1.1 Kurtosis: 1.1 After Mean: 3.1 STD: 0.5 Skew: -0.3 Kurtosis: 0.2 Comparison of 2006 and 2011 r = 0.62 n = 18,246
Female Unemployment Rate (SA) Transformation: natural log 2006 Before Mean: 8.3 STD: 7.3 Skew: 2.1 Kurtosis: 10.1 After Mean: 2.2 STD: 0.6 Skew: -0.1 Kurtosis: -0.3 2011 Before Mean: 15.5 STD: 9.5 Skew: 1.3 Kurtosis: 2.3 After Mean: 2.8 STD: 0.5 Skew: -0.3 Kurtosis: 0.3 Comparison of 2006 and 2011 r = 0.51 n = 18,246
Average Number of Persons per Room (SA) Transformation: truncated – natural log 2006 Before Mean: 0.51 STD: 0.09 Skew: 1.4 Kurtosis: 6.4 After Mean: -0.69 STD: 0.16 Skew: 0.5 Kurtosis: 0.7 2011 Before Mean: 0.51 STD: 0.18 Skew: 20.2 Kurtosis: 854 After Mean: -0.70 STD: 0.17 Skew: 0.7 Kurtosis: 0.3 Comparison of 2006 and 2011 r = 0.70 n = 18,246
Comparison of 2006 and 2011 Absolute Index Scores
Comparison of 2006 and 2011 relative Index Scores