THE 2011 POBAL HP DEPRIVATION INDEX
FOR SMALL AREAS (SA)
Statistical Features
Trutz Haase & Jonathan Pratschke
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
BASIC MODEL OF THE
POBAL HP DEPRIVATION INDEX
d1
Age Dependency Rate
d2
Population Change
d3
Primary Education only
d4
Third Level Education
d5
Persons per Room
d6
Professional Classes
d7
Semi- and Unskilled Classes
d8
Lone Parents
d9
Male Unemployment Rate
d10
Female Unemployment Rate
Demographic
Growth
Social Class
Composition
Labour Market
Situation
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%
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
12.0
9.9
STD: 29.1
STD: 20.1
Skew: 4.3
Skew: 1.3
Kurtosis: 34.9
Kurtosis:
.8
2011
Before
After
Mean:
Mean:
48.9
7.6
STD: 645.8
STD: 21.2
Skew: 34.8
Skew: 1.0
Kurtosis: 1527
Kurtosis: 1.0
r = 0.39
n = 18,246
AGE DEPENDENCY RATE (SA)
Transformation:
truncated at 70%
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
31.1
31.1
STD:
STD:
8.8
8.7
Skew: -0.35 Kurtosis:
Skew: -0.55 Kurtosis:
3.0
1.6
2011
Before
After
Mean:
Mean:
32.7
32.7
STD:
STD:
8.2
8.2
Skew: -0.71 Kurtosis:
Skew: -0.72 Kurtosis:
1.9
1.8
r = 0.75
n = 18,246
LONE PARENT RATE (SA)
Transformation:
natural log
2006
Before
After
Mean:
Mean:
20.9
3.3
STD: 17.5 Skew: 1.3 Kurtosis: 1.8
STD:
.54 Skew: 0.07 Kurtosis: -0.6
2011
Before
After
Mean:
Mean:
21.5
3.3
STD: 16.5 Skew: 1.2 Kurtosis: 1.4
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
After
Mean:
Mean:
18.7
3.6
STD: 12.1
STD: 0.3
Skew: 0.7 Kurtosis: 0.7
Skew: 0.02 Kurtosis: -0.7
2011
Before
After
Mean:
Mean:
16.0
3.7
STD: 10.7
STD: 0.3
Skew: 0.8
Skew: 0.2
Kurtosis: 0.5
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
After
Mean:
Mean:
30.9
3.6
STD: 16.8
STD: 0.4
Skew: 0.9 Kurtosis: 0.4
Skew: -0.17 Kurtosis: -0.14
2011
Before
After
Mean:
Mean:
30.7
3.6
STD: 16.6
STD: 0.4
Skew: -0.85 Kurtosis: 0.47
Skew: -0.20 Kurtosis: -0.12
Comparison of 2006 and 2011
r = 0.90
n = 18,246
HIGHER AND LOWER PROFESSIONALS (SA)
Transformation:
none
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
32.9
STD: 15.0
STD:
Skew: 0.4
Skew:
Kurtosis: -0.04
Kurtosis:
2011
Before
After
Mean:
Mean:
34.1
STD: 15.2
STD:
Skew: 0.4
Skew:
Kurtosis: -0.14
Kurtosis:
r = 0.89
n = 18,246
SEMI- AND UNSKILLED SOCIAL CLASSES (SA)
Transformation:
natural log
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
19.4
3.2
STD: 10.6
STD: 0.4
Skew: 0.8
Skew: -0.3
Kurtosis:
Kurtosis:
2011
Before
After
Mean:
Mean:
18.6
3.2
STD:
STD:
Skew: 0.7
Skew: -0.3
Kurtosis: 0.5
Kurtosis: -0.1
9.8
0.4
1.2
0.0
r = 0.81
n = 18,246
MALE UNEMPLOYMENT RATE (SA)
Transformation:
2006
Before
After
Mean:
Mean:
9.1
2.3
2011
Before
After
Mean:
Mean:
23.1
3.1
natural log
STD:
STD:
Comparison of 2006 and 2011
8.4
0.6
Skew: 2.4
Skew: 0.2
Kurtosis: 11.0
Kurtosis: -0.1
STD: 12.7
STD: 0.5
Skew: 1.1
Skew: -0.3
Kurtosis:
Kurtosis:
1.1
0.2
r = 0.62
n = 18,246
FEMALE UNEMPLOYMENT RATE (SA)
Transformation:
natural log
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
8.3
2.2
STD:
STD:
7.3
0.6
Skew: 2.1
Skew: -0.1
Kurtosis: 10.1
Kurtosis: -0.3
2011
Before
After
Mean:
Mean:
15.5
2.8
STD:
STD:
9.5
0.5
Skew: 1.3
Skew: -0.3
Kurtosis:
Kurtosis:
2.3
0.3
r = 0.51
n = 18,246
AVERAGE NUMBER OF PERSONS PER ROOM (SA)
Transformation:
truncated – natural log
Comparison of 2006 and 2011
2006
Before
After
Mean:
Mean:
0.51 STD:
-0.69 STD:
0.09 Skew: 1.4
0.16 Skew: 0.5
Kurtosis:
Kurtosis:
2011
Before
After
Mean:
Mean:
0.51 STD:
-0.70 STD:
0.18 Skew: 20.2
0.17 Skew: 0.7
Kurtosis: 854
Kurtosis: 0.3
6.4
0.7
r = 0.70
n = 18,246
COMPARISON OF 2006 AND 2011 ABSOLUTE INDEX
SCORES
COMPARISON OF 2006 AND 2011 RELATIVE INDEX
SCORES