Tuesday 15 January 2013

SIMD Trends

Details: the four waves of the SIMD between 2004 and 2012 allow for some analysis as to how Glasgow has changed over the last decade.

1%-15%: the most striking change has been the reduction in the proportion of Glasgow's population living in the bottom 15% of Scotland's datazones.  The convention has been to define deprivation as being people resident in the bottom 15% datazones in Scotland.  This has reduced from 53.4% in 2004 to 39.4% in 2012: a fall of 23.8%.  Put another way, between 2004 and 2012 73,600 people were lifted out of poverty, or 12.3% of the population (2011 estimate).  The bulk of the reduction came between 2004 and 2006 - and since then the fall has been less dramatic, but no less significant.


1%-5%: the same pattern can be seen with the number of people living in extreme deprivation - such as the bottom 5% of datazones in Scotland.  In Glasgow, this has fallen from 32.2% of the population in 2004 to 19.8% in 2012, equivalent to a fall of 63.5%.  Even so, the share of Glasgow's population in this category is four times as high as it would be, if deprivation was spread equally throughout Scotland.  It is also scarcely believable that in 2004 one in three of Glasgow's population lived in an area of extreme deprivation - yet that is what the data suggests.

16%-50%: with the population in the bottom 15% reducing in number in Glasgow, it is only to be expected that the population living in the 16%-50% category would increase.  And that is confirmed by the data: the proportion of the city's population living in these datazones in Glasgow increased from 25.9% in 2004 to 33.8% in 2012 - an increase of 34.7%.  This increase has been reasonably proportionate across the decade.

51%-100%: it is also notable that, just as the 16-50% category increased, so too has the number of people living in the 51%-100% group.  This has increased from 20.6% in 2004 to 26.9% in 2012, at an increase of 34.8%.  The significance of this is that it shows that the improvement in Glasgow has not just been at the margin of deprivation but throughout the population - that the city's experience has not simply been a reduction in deprivation but also an increase in the number of people living in the top half of Scottish society.  But a sense of perspective is also required, as the city's population in this category is around half of what it would be if it were distributed equally across Scotland.  Also, the increase mainly took place between 2004 and 2006, with little real change between 2009 and 2012.

Analysis: this improvement in the reduction of deprivation in Glasgow has been driven by a number of factors: 

  • Employment: the number of people in work has increased and was the main factor in reducing deprivation in the early part of the decade.  Given the time lags inherent in the data, the employment rate increased from 54.9% in March 1999-February 2000 to 64.3% in March 2003-April 2004;
  • Housing change: the decade has also seen an ambitious programme of housing demolition led by the Glasgow Housing Association involving the rehousing of a substantial number of people.  Three datazones have had all their multi-storey housing demolished: in S01003031 (Castlemilk, 2001 population 523), S01003319 (Ibrox, 804) and S01003505 (Sighthill, 722); and other demolitions have taken place in Red Road and Shawbridge, amongst others.  All of these areas were in the bottom 15%  in 2004 and through the demolition programme no longer feature in this category;
  • Demographic change: since 2001 the proportion of the city's population aged between 25 and 44 has increased, from 182,300 (31.5% of the total) to 196,800 (32.9%) at a time when the Scottish total declined from 29.2% to 26.4%.  As this group has the highest employment rate of any other age group, the outcome of this shift will have been to contribute to the overall reduction in deprivation.

Tuesday 4 December 2012

Overall Trends

The overall details of datazones in the bottom 15% in Glasgow are as follows.  This table gives the details of datazones in Glasgow in the bottom 976 datazones in Scotland.

Year
No Datazones
Population
% City Total
SIMD 04
373
309,000
53.4%
SIMD 06
330
269,100
46.5%
SIMD 09
302
245,300
42.0%
SIMD 12
289
235,400
39.4%

The release date of the SIMD does not always correspond to the latest date of the data.  Consequently, the population details for 2001 have been used for the SIMD04, 2004 for SIMD06, and 2008 for SIMD09.  For the 2012 SIMD, the population mid-year estimate for 2011 has been used (note - not the Census).  This table clearly shows the decline in the proportion of Glasgow's population living in a deprived area.

The same decline can be seen when a tighter definition of deprivation is used, such as the bottom 5%, or the 325 most deprived datazones in Scotland.

Year
No Datazones
Population
% City Total
SIMD 04
226
186,600
32.2%
SIMD 06
169
132,800
22.9%
SIMD 09
158
126,100
21.6%
SIMD 12
148
118,400
19.8%


If there is a decline in the 1%-15% category, it follows there must be an increase somewhere else.  To start with, the following table looks at the number of datazones in the 16%-50% category (ranking 977 to 3,252) for the four SIMD waves.

Year
No Datazones
Population
% City Total
SIMD 04
182
150,150
25.9%
SIMD 06
195
164,000
28.3%
SIMD 09
215
181,000
31.0%
SIMD 12
228
202,300
33.8%

And this table covers the number of datazones in the top half of the SIMD distribution - the 51%-100% group, that includes datazones ranked 3,253 to 6,505.

Year
No Datazones
Population
% City Total
SIMD 04
139
119,500
20.6%
SIMD 06
169
145,700
25.2%
SIMD 09
177
157,900
27.0%
SIMD 12
177
161,100
26.9%

Initial Release and Analysis

As the 2012 Scottish Index of Multiple Deprivation is released on 18th December 2012, there is only a limited amount of work that can be done prior to its initial release.  However there are some possible avenues of work that we know can be developed.

Change over time: as datazones have consistent boundaries, the results for 2012 can be compared with the SIMDs for 2004, 2006 and 2009, to build up a consistent picture of how areas have changed (or not changed) over the last decade.

Relationship with other data: we can relate the SIMD details with other data sources to build up an understanding of the factors that might be driving the change in particular areas.  Demographic trends (particularly involving the 25-44 age group), house price and housing tenure (esp the private rented sector) and ethnic diversity are the most obvious areas of comparison.

Use of the Index: the SIMD has been designed to identify areas of multiple deprivation, and to this end the convention has been to define those areas in the bottom 15% datazones (ie the bottom 976 out of Scotland's 6505 datazones) as being deprived.  This is of course an arbitrary definition - but it does open up the opportunity to look at other groupings, including
  • Detailed analysis of the 5% most deprived datazones, which may be a more accurate definition of deprivation;
  • Matching relative change to absolute change;
  • Using the Index to describe change unrelated to deprivation, such as the 16%-50% and 51%-100% categories;
  • Comparing Glasgow with other surrounding local authorities.
A workplan will be developed to cover these themes and relevant analysis will be featured on this blog.