1. Estimating segregation and diversity of ethnic groups over time in England and Wales, 1991-2001 Albert Sabater Cathie Marsh Centre for Census and Survey Research Understanding Population Trends and Processes

2. Estimating segregation and diversity of ethnic groups over time in England and Wales, 1991-2001 Outline Motivation Main aims Data (census and full estimates) Method (indices of segregation and diversity) Results (nationally and for some LADs)

3. Motivation (recent views of segregation) Segregation at levels of black ghettoes in US cities (Guardian, 1 Sept 2005); Are we sleepwalking towards apartheid? (Sunday Times, 18 Sept 2005); Multiculturalism is falling to bring Britain’s races together (Ted Cantle, Times, 21 Sept 2005); Debate based on the view that too many Black people or too many Asians living together is a problem, while the same dominance by White people is acceptable. (GLA, 10 Nov 2005).

4. Main aims 1.Examine the impact of using census output on measures of segregation and diversity; 2.Analyse segregation measures over time using cohort comparisons; 3.Evaluate challenges posed by boundary revisions.

5. Data Two data sources 1.Census output as published (CASWEB) 2.Full population estimates (CCSR, soon at ESDS)

6. Enhancement, 1991 and 2001 censuses AdjustmentsGlobal impact, England and Wales 1. Population definition a.Students, transferred from vacation address to term-time address (1991 only) 53,975 net addition 213,628 net gain for 103 districts 159,653 net loss for 273 districts a.Population date, change from census day to mid-year 1991: April 21 to June 30 2001: April 29 to June 30 43,094 net addition 41,006 net addition 2. Non-response not estimated within census outputIn 1991, 1.6% addition In 2001, 0.5% addition 3. Harmonisation of geographical units Smallest 1991 areas converted to 2001 Census units 139 of 403 local authority boundaries and 4,398 of 9,527 electoral ward boundaries changed involving more than 1% of their population

7. Impact on population change by ethnic group in EW

8. Method 1.Index of Dissimilarity (an unequal geographical spread); 2.Index of Isolation (high proportion of ethnic groups); 3.Reciprocal Diversity Index (approximate equality of numbers of each ethnic group).

9. Let's recapitulate objective 1 Examine the impact of using census output on measures of segregation and diversity; Example…

10. Index of dissimilarity between 91-01 for EW -measured across wards- ID values 1991 Census 2001 Census Difference White 61.458.8-2.6 Caribbean 68.967.1-1.8 African 71.170.6-0.5 Indian 65.362.1-3.1 Pakistani 75.171.8-3.4 Bangladeshi 74.271.7-2.5 Chinese 42.242.0-0.2 1991 Full estimates 2001 Full estimates Difference 60.557.3-3.1 68.065.7-2.3 69.669.4-0.2 64.260.9-3.3 74.269.7-4.5 72.767.9-4.8 42.537.5-5.0

11. Index of isolation between 91-01 for EW -measured across wards- P* values 1991 Census 2001 Census Difference White 95.393.5-1.9 Caribbean 7.67.3-0.3 African 4.38.23.8 Indian 15.615.5-0.1 Pakistani 13.917.43.5 Bangladeshi 10.913.72.9 Chinese 0.81.20.4 1991 Full estimates 2001 Full estimates Difference 94.993.3-1.6 7.97.1-0.8 4.68.03.4 15.515.2-0.3 14.016.82.8 10.913.22.3 0.91.10.1

12. Index of diversity between 91-01 for LADs of EW 1991 Full estimates 2001 Full estimates

13. Let's recapitulate objective 2 Analyse segregation measures over time using cohort comparisons; Example… Aged 0-6 10-16 1991 2001

14. Index of dissimilarity between 91-01 for EW

15. Index of isolation between 91-01 for EW

16. Let's recapitulate objective 3 Evaluate challenges posed by boundary revisions. Example…

17. Index of dissimilarity between 91-01 for EW and Leicester -measured across wards- ID values 1991 Census 1991 Census 2001b Difference White 61.460.9-0.5 Caribbean 68.968.6-0.3 African 71.170.7-0.4 Indian 65.364.8-0.5 Pakistani 75.174.5-0.6 Bangladeshi 74.273.1-1.1 Chinese 42.241.0-1.2 1991 Census 2001b Difference 53.847.1-6.7 28.926.5-2.4 30.927.7-3.1 54.848.4-6.4 47.245.7-1.6 73.768.5-5.2 32.827.2-5.6

18. To sum up -Ethnic groups have become more evenly distributed since 1991; -Groups with a recent history of immigration (African, Pakistani and Bangladeshi) have increased their average local concentration since 1991; -Diversity is increasing, and becoming more widespread; -Ethnic groups vary their evenness and exposure at different life-stages; -The impact of boundary changes is significant and can be of the same order of changes over time.

19. Dissemination of full estimates Summary ward data available at www.ccsr.ac.uk/popla/TimeSeriesOutput.shtml