1. The 2011 Pobal HP Deprivation Index for Small Areas (SA) Statistical Features
Dublin, August 2012

2. Introduction to The 2011 Pobal HP Deprivation Index
This presentation highlights some of the more technical issues in the construction of the 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 Absolute Index Scores
The change in the Relative Index Scores

3. 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

4. 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

5. 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

6. 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: 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

7. Age dependency Rate (SA)
Transformation: truncated at 70%
2006
Before Mean: 31.1 STD: 8.8 Skew: Kurtosis: 3.0
After Mean: 31.1 STD: 8.7 Skew: Kurtosis: 1.6
2011
Before Mean: 32.7 STD: 8.2 Skew: Kurtosis: 1.9
After Mean: 32.7 STD: 8.2 Skew: Kurtosis: 1.8
Comparison of 2006 and 2011
r = 0.75
n = 18,246

8. 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

9. 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

10. 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: Kurtosis: -0.14
2011
Before Mean: 30.7 STD: 16.6 Skew: Kurtosis: 0.47
After Mean: 3.6 STD: 0.4 Skew: Kurtosis: -0.12
Comparison of 2006 and 2011
r = 0.90
n = 18,246

11. 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

12. 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

13. 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

14. 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

15. 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: STD: 0.16 Skew: 0.5 Kurtosis: 0.7
2011
Before Mean: 0.51 STD: 0.18 Skew: 20.2 Kurtosis: 854
After Mean: STD: 0.17 Skew: 0.7 Kurtosis: 0.3
Comparison of 2006 and 2011
r = 0.70
n = 18,246

16. Comparison of 2006 and 2011 Absolute Index Scores

17. Comparison of 2006 and 2011 relative Index Scores