Nigel Swier ONS - Migration Statistics Improvement Work

Migration Statistics Improvement Work

Nigel Swier

ONS Centre for Demography

Context

• Migration is a key part of population change

• It is difficult to measure

• There is no direct source or register

• Estimated using surveys and other sources

Context - Change

UK Components of Change, mid-1991 to mid-2007

-50

0

50

100

150

200

250

300

1991

-199

2

1992

-199

3

1993

-199

4

1994

-199

5

1995

-199

6

1996

-199

7

1997

-199

8

1998

-199

9

1999

-200

0

2000

-200

1

2001

-200

2

2002

-200

3

2003

-200

4

2004

-200

5

2005

-200

6

2006

-200

7

Th

ou

san

ds

Natural change Net migration & other changes

Importance of Population Estimates

• Local authority resource allocation

• Planning and monitoring service provisione.g. education and health services

• Grossing up survey resultse.g. Labour Force Survey

• Denominators in the derivation of ratese.g. GDP, unemployment rates, mortality & fertility

rates, performance indicators

Work Programme

• Data sharing legal gatewaysSchools Census, Migrant Worker Scan, student data

• Statistical research and development• Source data improvements

e.g. Port Survey Review, patient register, new surveys

• Work in kind by other government departments

e.g. E-Borders, DWP outputs

• Reporting strategy• User engagement

Already Implemented

• Improvements to methods in 2007 – distribution of migration, emigration modelling

• Improved port survey– Better coverage of migrants at key ports in IPS

• More coherent migration reporting– Quarterly report and less confusion on on multiple

outputs across government

• Indicators of migration and improved timeliness• National level estimates of short-term migration

Next Improvement Package

• Distribution of international migration using administrative data

• Student adjustments using HESA data• Refinements to previous methods• Local level short term migration estimates• Quality measures around population

estimates• Indicators and early migration outputs

What changes numbers?

Distribution of international migration• Issue: Current method uses 2001 Census –

out of date distributions?• Solution: Use timely administrative sources in

conjunction Internal migration flows• Issue: Current source (patient registers) can

be slow at recording moves e.g. of students• Solution: Enhance with HESA student data

which includes term-time address

Quality Assurance

Published QA Strategy (June 2009)• ONS development protocols met (Methdology

QA panels)• External reference panels in development• Local Insight Reference Panels to sense-

check outcomes• Expert peer review (academics etc)• Consultation and engagement

Consultation

• Indicative impacts published 30 November– Impact of improvements for all LAs presented– Supporting methodology documentation

• Consultation period to 18 January 2010– Opportunity for users to provide input

• Seven regional roadshow seminars in December– Manchester, Birmingham, York, London, Bristol, Leicester,

Llandindrod Wells

• Revised back series for estimates 2002-2008 will be published 27 May 2010

Next Phase

• More extensive use of administrative data for statistical purposes– More data sharing gateways– Linking and matching between sources

• E-Borders roll-out– Improved counts of migrants into and out of UK

• Better quality measures– Ability to make statements about confidence in figures

• 2011 Census– Basis of estimation for the next decade

Keeping up to date

• Quarterly updates and other information at www.statistics.gov.uk/imps

• Implementation seminars• Consultation period• Email: imps@ons.gsi.gov.uk