Geographical Inequalities and Population Change in Britain, 1971-2011

1. Geographical Inequalities and Population
Change in Britain, 1971-2011
Chris Lloyd, Nick Bearman, Gemma Catney
Centre for Spatial Demographics Research, University of Liverpool, UK
Email: c.d.lloyd@liverpool.ac.uk
Twitter: @lloydcd
BSPS 2015, University of Leeds, 7-9 September

2. Outline
1. Population Change and Geographic
Inequalities in the UK, 1971-2011: ESRC project
outline
2. Creating population surfaces
3. Population change 1971-2011: some
provisional analyses

3. Project outline
• Identification of comparable variables from the UK Censuses
of 1971, 1981, 1991, 2001 and 2011
• Creation of population surfaces for Britain for all comparable
variables (1km cells nationally and 100m cells for urban areas;
in Northern Ireland grid square counts for 1971-2011 are
already available)
• Provision of population surfaces, code in R programming
language to manipulate data and an online atlas of
population change
Project due to complete July 2016

4. Creating population surfaces
• Selected comparable variables for 1971, 1981, 1991, 2001
and 2011
• Overlay enumeration districts or output areas with landuse
data (or using postcodes, etc)
• Use areal weighting to estimate populations of each
populated area (e.g., landuse not water)
• Overlay output with1km grid
• Use areal weighting to estimate populations of each
populated segment
• Aggregate counts within grid cells
• Smooth grid cells to make neighbouring cells similar
In the provisional analysis which follows, simple overlay of
EDs/OAs and a 1 km grid is conducted with no smoothing

5. Population change 1971-2011
• Population surfaces generated for 1971 and 2001 for
- Total persons
- Unemployed persons (% of employed and unemployed)
- Non owner occupied households (%)
- Households without access to a car or van (%)
- Households with more than one person per room (%)
• From the latter four, z scores were derived (percentage-
mean / standard deviation) and these were summed to
derive a deprivation score (following Townsend)
• Gridded counts and difference maps (2011-1971)
- Total persons, Unemployed persons (%), Townsend score
• Analysis of population spatial distribution using index of
dissimilarity and Moran’s I autocorrelation coefficient
• Correlations between counts/percentages/scores for 1971
and 2011

6. Total persons in 2011 Total persons 2011-1971

7. Unemployed persons (%) in 2011 Unemployed persons 2011-1971

8. Townsend score in 2011 Townsend score 2011-1971

9. Unevenness and clustering: 1971 and 2011
Index of dissimilarity, D
Unemployed Non Own Occ HH No Car HH > 1 PPR Townsend
1971 0.793 0.767 0.809 0.852 0.789
2011 0.724 0.726 0.759 0.726 0.719
Moran’s I (queen contiguity) for percentages and Townsend
deprivation score
Unemployed Non Own Occ HH No Car HH > 1 PPR
1971 0.224 0.423 0.298 0.328
2011 0.226 0.348 0.327 0.406

10. Unevenness and clustering
• Decrease in clustering by unemployment, housing tenure,
car and van access and overcrowding (and thus deprivation
as a whole)
• Decrease in unevenness of the population by housing
tenure (impact of right to buy?),
• Increase in unevenness by car and van access and
overcrowding
These findings appear to reflect an increased urban-rural
contrast (clustering – the tendency for neighbouring areas to
be alike – will decrease if urban areas become more distinct
from suburban areas while unevenness will increase)

11. Characterising spatial structure
z(xi) is a percentage, or
score at location xi
p(h) is the number of data
pairs separated by the lag
(distance and direction) h
Variogram: spatial dependence at different spatial scales
2
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)(ˆ hxx
h
h
h
 
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p
i
zz
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1. Take each data value in turn and compute its squared
difference from each of the other values in the data set and store
the distances between them
2. Group these differences into distance bins – e.g., all squared
differences for pairs separated by 1 to 2 km and compute half of
the average of these differences
3. Plot these (half) average differences against distances
4. The plot shows how difference between values changes as a
function of distance

12. Bounded variogram model: nugget and effect and spherical component.
Provides a composite measure of clustering and polarisation: small nugget
indicates localised clustering – with a large sill this indicates polarisation
Variogram model

13. Simulated surfaces: spherical model with a = 2 and 40.
Variograms

14. Variograms for Townsend scores:
1971 and 2011
Increased variation in 2011 but also greater spatial continuity in
scores over regional scales (larger ranges)

15. Relationships between 1971 and 2011
counts, percentages and deprivation scores
Correlation coefficient for percentages (all significant at
the 0.01 level)
Totalpersons
Unemployed
NonOwnOcc
HHNoCar
HHgt1ppr
Townsend
2011 2011 2011 2011 2011 2011
Total persons 1971 0.934
Unemployed 1971 0.176
Non Own Occ 1971 0.516
HH No Car 1971 0.569
HH gt 1ppr 1971 0.113
Townsend 1971 0.406

16. Relationships between 1971 and 2011
counts, percentages and deprivation scores
Correlation coefficient for percentages (all significant at
the 0.01 level)
Totalpersons
Unemployed
NonOwnOcc
HHNoCar
HHgt1ppr
Townsend
2011 2011 2011 2011 2011 2011
Total persons 1971 0.929
Unemployed 1971 0.252
Non Own Occ 1971 0.515
HH No Car 1971 0.698
HH gt 1ppr 1971 0.248
Townsend 1971 0.583
For cells >= 25 people in 1971 and 2011

17. Summary
• The provisional analyses indicate the value of being able to
explore population change over small areas
• Large decreases in total population (2011-1971) highlighted
in some urban areas, with increases in parts of London and
other areas away from the larger cities and towns
• Suggestion that unemployment and deprivation (Townsend
score) increased in urban areas
• Decrease in unevenness of the population by housing
tenure, increase in unevenness by car and van access and
overcrowding
• The resource will enable geographically- and attribute-rich
analyses of population change in the UK and, specifically, the
ways in which the population has become more or less
geographically unequal

18. Acknowledgements
Support from the ESRC is acknowledged gratefully
(Grant Ref No ES/L014769/1). Team members also
include Alex Singleton and Paul Williamson and
Richard Prothero at the ONS.
The Office for National Statistics are thanked for
provision of the data.
Office for National Statistics, 2011 Census: Digitised
Boundary Data (England and Wales) [computer file].
ESRC/JISC Census Programme, Census Geography
Data Unit (UKBORDERS), EDINA (University of
Edinburgh)/Census Dissemination Unit. Census output is
Crown copyright and is reproduced with the
permission of the Controller of HMSO and the Queen's
Printer for Scotland.