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Population Projections by Ethnic Group Pete Large ONS

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Presentation on theme: "Population Projections by Ethnic Group Pete Large ONS"— Presentation transcript:

1 Population Projections by Ethnic Group Pete Large ONS

2 Population Projections by Ethnic Group Estimates and projections by ethnic group Deriving the ethnic dimension Implementation and output Ethnicity in the 2011 Census

3 Population Projections National (GAD), 25/40/70 years Sub-National (ONS), 25 years, LADs Ethnic (ONS), 10 years, LADs ?, 16-way classification

4 Population Projections by Ethnic Group Feasibility study in 2002 ‘Spin off’ of Ethnic Estimates work To cover England (and subdivisions) only Methodology to be QA’d Release as Experimental Statistics possible in December 2005 (subject to review)

5 Projection Method Cohort Component Method Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1 Constrain to Sub-National Projections

6 Difficulties of Ethnic Projections Lack of key data with ethnic dimension: –Need to use proxies –Use data from different sources Inconsistent classifications Small groups

7 Size of Ethnic Groups As a percentage of the population of England White: British = 87.0% Next largest: White: Other = 2.7% 10 groups each have less than 1.0% Source: Table KS06, 2001 Census, ONS, Crown Copyright

8 Cumulative Proportion of non-White: British (LADs in England) Cumulative proportion Number of LADs Source: KS06, 2001 Census, ONS, Crown Copyright

9 The Ethnic Dimension: Fertility Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1

10 Fertility Need relative level and shape of age-fertility curves Possible sources: Birth Register (COB), LFS, Hospital Episode Statistics, Longitudinal Study, 2001 Census

11 Population of England and Wales: Percentages born in UK 91% of all people born in UK 41% of non White: British born in UK White British:98% Other White20% Asian groups47% Black groups 49% Other groups34% Note: Data is for England and Wales. Source S102, 2001 Census, ONS, Crown Copyright

12 Fertility 2001 Census provides numbers of 0 year olds to mothers of each ethnic group by SYOA Implied ‘relative fertility rate’ applied to Sub- National Projections (SNP) curves Project changes in relative fertility ? Total births for each age/area constrained to SNP

13 Illustrative Fertility Profiles Note: Data illustrative only

14 Illustrative Calculation of Fertility Rate Census Age-Specific Fertility Rates (Age 29, England) All groups0.094 Black: African0.124 Relative ASFR = 0.124 / 0.094 = 1.314 Sub-National Projections Age-Specific Fertility Rate (Age 29, LAD x) = 0.1 Estimated ASFR (Age 29, LAD x, Black African) = 1.314 x 0.1 = 0.131

15 Married Women in Inter-Ethnic Marriages White: British3% White: Irish63% Mixed: White and Asian 82% Asian: Indian9% Black: Black Caribbean 25% Black: Other66% Chinese29% Source: Focus on Ethnicity & Identity, ONS, at, Crown Copyright

16 Allocation of Births to Ethnic Group 2001 Census provides ethnicity of mother by ethnicity of child for SYOA 0-9 Assumed different patterns for London and the rest of England Linear projection from 1997-2001 to 2013 ?

17 Getting the probabilities wrong … Note: Illustrative data only

18 The Ethnic Dimension: Mortality Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1

19 Mortality Unlikely to be key factor in estimates of population by ethnic group Country of birth as proxy ? Confounded with area effects Constrain to SNP – mortality rates as an output

20 ‘Ethnic Switching’ Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1

21 Switching between Ethnic Group Using 1991/2001 Census data from Longitudinal Study BUT –Imputation –Response by others in household –Change in ethnic classification Unable to reliably estimate switching effect

22 The Ethnic Dimension: Migration Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1

23 Migration Domestic Migration (within England) Migration to/from rest of UK International Migration –IPS/VS –Asylum Seekers –Irish

24 Domestic Migration Need to establish: –Relative propensity to migrate –Likely destination Relative propensity to migrate: Census data on age-migration profiles Likely destination: –Age effect –Ethnicity effect Each flow A->B constrained to Sub-National Projection

25 Migration from Rest of UK Rest of UK assumed exogenous In-migration decomposed using 2001 Census ethnic proportions for in-migrants Investigate possibility of ‘ethnic effects’ Constrain to Sub-National Projections for each part of ROUK/area within England

26 Migration to Rest of UK Similar methodology to domestic migration Takes account of age structure and ethnic effects for each area Some aggregation of groups required for Scottish data Ethnic composition of flow to Northern Ireland assumed same as inflow

27 IPS/VS Migration: Outflow IPS data on COB/Country of Next Residence Census data on COB/Ethnicity Care needed for some small flows

28 IPS Migration: Outflow ComponentCumulative % of migrants British citizens travelling to EU/USA/Australia/Canada/NZ /South Africa 43 EU citizens travelling to the EU 55 Commonwealth citizens travelling to Canada/SA/Australia/NZ 68 ……

29 IPS/VS Migration: Inflow Option 1: Adjust 2001 Census counts of migrants for Asylum Seekers and Irish flows in each area Apply derived rates to Sub-National Projections flows Option 2: Do the same as with outflow (use COB to derive ethnicity from Census data).

30 Asylum Seekers Take account of both inflow and outflow Home Office data on nationality of asylum seekers over past 5 years Census data on COB/Ethnicity White: British set to zero Apply rates to Sub-National Projections This component subject to substantial variation

31 Irish Flows Option 1 Assume ethnic composition is same as flows to/from Northern Ireland Option 2 Use ethnic composition of inflows from Ireland measured in the Census (and assume same applies to outflows)

32 The Ethnic Dimension: Starting Population Y n+1 = Y n + B n+1 – D n+1 + S n+1 + N n+1

33 Starting Population Apply projection method to 2001 Census data to mid-years 2001-2003 Allow for special populations of Armed Forces, school boarders and prisoners (Aim to be consistent with Mid-Year Estimates)

34 Variability of Projections Projections NOT Forecasts Constraining totals given by National/Sub-National Projections Statistical error in estimating parameters Correspondence between alternative plausible methodologies

35 Implementation and Output Projection/estimates systems written in SAS System runs for LADs and 16-way ethnicity (any aggregation done at end) Output likely to follow Mid-Year Estimates/Sub-National Projections –England: SYOA to 85 by ethnicity –LADs (?): Quinary age to 85 by ethnicity Results expected to be available in Excel/CSV format on website

36 Census 2011 consultation - Ethnicity, Identity, Language and Religion Consultation on topics runs 16 May to 5 Aug 2005 Aiming to establish users’ data requirements and build on ONS’s current understanding –Topics which have a clear case for inclusion: Ethnicity, religion and national identity Country of birth Welsh/Irish/Gaelic proficiency in Wales/Northern Ireland/Scotland –Topics which need further investigation: Nationality/citizenship –Topics which have insufficient evidence of user need: Country of parents’ birth English language proficiency

37 Census 2011 Consultation web page For more information on the consultation, including how to respond:

38 Population Projections by Ethnic Group Questions ?

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