Sample of Anonymised Records: User Meeting

Propensity to migrate by ethnic group: 1991 & 2001

Paul Norman 1, John Stillwell 2 & Serena Hussain 2

School of Geography, University of Leeds

1 ESRC RES-163-25-0032

2 ESRC RES-163-25-0028

Internal migration of Britain's ethnic populationsJohn Stillwell & Serena Hussain

• Understand how migration intensities and patterns vary between ethnic groups at various geographical levels in 2001 and what changes can be identified between 1991 & 2001

What happens when international migrants settle? Ethnic group population trends & projections for UK local areas under alternative scenariosPhil Rees, Paul Norman & Peter Boden

• Investigate trends in migration propensities by ethnic group & need age-specific migration rates for projections

Research questions …

• Do propensities to migrate vary by ethnic group, age, sex at the national level and for sub-national areas?

• How do spatial patterns of internal ethnic group migration vary with spatial distribution of ethnic populations and immigration at LAD scale, 2000-01?

• What are the characteristics of the origins and destinations of ethnic group migrants in 2000-01 at ward level?

• What other factors influence migration propensities?

• Have there been any changes between 1991 & 2001?

Specification …Stillwell & Hussain have commissioned tables from ONS, one of which is for flows at LAD scale in England & Wales:

Ethnic groups consistent with ethnic group data in SMS Reasonable geographical detail but lacks information on:• sex & other factors & is only for 2000-01

Age White IndianPakistani & other South

AsianChinese

African, Caribbean, Black British &

other BlackMixed Other

0-15

16-19

20-24

25-29

30-44

45-59

60+

Specification …Data sources: 1991 & 2001 Individual Licensed SARStudy population: household & communal establishment residents in England & Wales, excluding recent immigrantsClose as possible to the ethnic group and age detail from the commissioned table, plus sex, migrant status and region (GOR)

Derive variables consistent for 1991 & 2001 that the literature shows to be related to the propensity to migrate:• Social Class• Educational achievement (degree)• Tenure (owners, public renters, private renters, communal)• Employment status (active, unemployed, other)• Health (reported limiting long-term illness)

Deriving variables … Ethnicity

Aim 1991 Indiv. SAR 2001 Indiv. SAR Best fit

• White • White

• British• Irish• Other White

• White

• Indian • Indian • Indian • Indian

• Pakistani & other South Asian

• Pakistani• Bangladeshi

• Pakistani• Bangladeshi

• Pakistani & other South Asian

• Chinese • Chinese • Chinese • Chinese

• African, Caribbean, Black British & other Black

• Black African• Black Caribbean• Black Other

• Black Caribbean• Black African• Other Black

• African, Caribbean, Black British & other Black

• Mixed • Not available

• White & Black Caribbean• White & Black African• White & Asian• Other Mixed • Other

• Other• Other Asian• Other-Other

• Other Asian• Other

Deriving variables … Social ClassAvailable in 1991, emulated in 2001 using NS-SEC

• Age (0-15; 16-19; 20-24; 25-29; 30-44; 45-59; 60+)• Migrant status (year before census) (y/n)• Educational achievement (degree)• Tenure (owners, public renters, private renters)• Employment status (active, unemployed, other)• Health (reported limiting long-term illness)

Deriving variables … Government Office RegionAvailable in 2001 SAR, needs estimating for 1991

1991‘areap’

2001‘GOR’Link to GOR via

Centroid

GOR added to 1991 individual records using ‘areap’ link

Contextual information1991: economic depression, high unemployment2001: economically buoyant, low unemploymentRegional migration rates, different pattern

Government Office Region 1991 migration rates 2001 migration rates

North East 7.79 9.10

North West 7.80 8.63

Yorkshire & The Humber 8.52 9.37

East Midlands 8.50 8.67

West Midlands 7.56 7.82

East of England 9.27 7.78

London 10.45 9.69

South East 10.06 8.27

South West 10.25 9.48

Wales 7.65 8.43

England & Wales 8.97 8.71

Modelling migration: logistic regressionOutcome variable• Dichotomous categorical outcome: Did / Did not migrate• Model predictions to lie between 0 & 1

Explanatory variables• Categorical or continuous

Model outputs• Odds of event compared with a ‘base’ or ‘reference’ level• Can be expressed as probabilitiesDale A, Fieldhouse E, Holdsworth C (2000) Analyzing Census Microdata. Arnold: London

Series of models developed• Simple then adding in various factors• ‘Interactions’ explored

Modelling migration probabilities … (model n)Influences on migration (year before census)

continued …

Modelling migration probabilities … (model n)Influences on migration (year before census)

continued …

Modelling migration probabilities … (model n)Influences on migration (year before census)

continued …

Modelling migration probabilities … (model n)

Modelling summary …Ethnicity• South Asian groups less likely to migrate than White group• White group propensities higher in 2001 than 1991• Chinese, Black & Other groups higher odds of migration in 1991, but less difference from White group by 2001

Other factors consistent with literature

Government Office Region: complex picture

Rates 1991

Rates 2001

Rates in NE from 7.79%

to 9.10%

Using the model outputs …Modelled migration probabilities by ethnic group

For forecasting scenario models • Estimate single year of age & trends• Corroborate from other sources

SARs goods & less than goods …SARs, < goods … • Inconsistencies between 1991 & 2001 extracts, e.g. variable definitions, geography & different decisions by UK’s NSAs• Delays for 2001 release, loss of momentum• For 2011 need continuity from previous censuses• Loss of variable detail down to lowest in common?

SARs microdata a great resource• Large sample size• Extraction of study population of interest• Derivation of variables & versatile crosstabulations• Comparisons between 1991 & 2001 & then 2011• Modelling techniques