The micro-geography of UK demographic change 1991-2001

Paul NormanSchool of Geography, University of Leeds

Understanding Population Trends and Processes

ESRC RES-163-25-0012 for 2005-07 @ 40%

Main aim

Quantify and map changes in population size and social characteristics which occurred in UK’s small geographical areas between the 1991 and 2001 Censuses

Small area geography of reporting: wards & equivalents

Population change

• Which demographic components account for change? Balance between natural change & migration change

Area characteristics change

• Are areas becoming more or less deprived over time? Which area attributes change & why?

The micro-geography of UK demographic change 1991-2001

Population change

• Data preparation & number crunching: mostly completed

• Analysis: yet to be carried out

Area characteristics change

• Data preparation & number crunching: partly completed

LGA presentation

• Background

• Data problems & solutions

• Preliminary results

Use of area characteristics measures Cross-sectional research

• Allocation of funding

• Business marketing

• Deprivation relationship with health

Time-series: deprivation measures

• Are areas becoming more or less deprived over time?

• Has regeneration policy been effective?

• Have patterns of unemployment changed?

• Has public housing gone into private ownership?

• Has health improved in areas now less deprived?

Background: Classification of areasUse of multiple input variables to produce a summary measure of an area’s characteristics

• Charles Booth, late 19th Century • Human Ecologists, Chicago 1920s• Social Area Analysis• Factor Analysis / Principal Components Analysis• Deprivation Indexes • Geodemographics

Location Demographic Household Employment Education Health

Area 1

Area 2

Area 3

Classification of areasProblems when comparing areas at 2 (or more) time points

Input data• Availability, definition and categorisation

Geography• Boundary change

Method of classification• Applicability over time

Need to compare like with like & need consistency of information, geography & methodOtherwise comparisons invalid

Input data: availability, definition & categorisation

Area classification using Census data 1991 & 2001

• Topics & questions change• Where available across time, tabulation categories vary• More variables implies less consistency• Large number of input variables too cumbersome

Aim …Emulate deprivation indexes (e.g. 4 inputs) more realistic as a goal than geodemographics (e.g. 41 variables in ONS 2001 OA classification by Dan Vickers)

Input data

Indexes widely used since 1980s

Townsend index Carstairs index• Unemployment • Male unemployment• Household overcrowding • Household overcrowding• No access to car • No access to car• Non-home ownership • Low social class

Townsend variables stable & comparable over timeCarstairs

• Male unemployment too narrow• Low social class misses/misclassifies people

Geography: small area boundary change

Ward boundaries change to maintain sub-district equality in elector to councillor ratios

Census data: smallest areas Enumeration Districts in 1991 a different geography to 2001 Output Areas

Data collected & released for 1991 small areas cannot directly be compared with 2001 data

Geography: Ward boundary change

Yellow wards in 2001 = no boundary change

Geography: Adjusting data between boundary systemsMethods by ESRC funded research (Simpson 2002; Norman et al. 2003)

Postcodes associated with

1991 EDs

Postcodes associated with

2001 OAs

Apportion data using weighted postcode distribution

Method of area classification

Geodemographic cluster algorithms may be usable at two or more time-points to classify areas (more work needed)

Are deprivation index methods usable across time?• Input variables reveal each area’s situation relative to national level• In 1991, is unemployment for area 1 more or less than England & Wales as a whole?

Decide on national comparison level• 1991, 2001 or an average

Deprivation 1991 & 2001

Townsend index• Unemployment• Household overcrowding• No access to car• Non-home ownership

Data for 1991 EDs converted to 2001 OAs to capture sub-ward distributions, then aggregate to wardsCalculate 1991 and 2001 indexesComparison relative to 2001 levels

Deprivation 1991 & 2001

Less deprived2001 averageMore deprived

Deprivation 1991 & 2001

Why has deprivation changed 1991-2001?Change at national level

• Unemployment 9% to 5%• Household overcrowding 2% to 1.5%• No access to car 27% to 22%• Non-home ownership 30% to 28%

Local variations: yet to investigate

Employment sector changesTenure changesRegeneration schemes

• Database?

Effect of changing deprivationLimiting long-term illness 1991 & 2001

1991

2001

Is increasing deprivation over time associated with worse health?

The micro-geography of UK demographic change 1991-2001

Ongoing work …

Population change

• Which demographic components account for change? Balance between natural change & migration change

Area characteristics change

• Are areas becoming more or less deprived over time? Which area attributes change & why?

Analysis for both to be done

Area characteristics data preparation for Scotland and Northern Ireland