internal migration research update kostas loukas, population statistics research unit...
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Internal Migration Research Update
Kostas Loukas, Population Statistics Research Unit
Aims
• Brief background on the current method and an update on research being carried out into improving internal migration estimates
• Case studies to highlight findings from the research into specific changes
• Next steps
• Discussion and feedback of the issues being investigated
Importance of Internal Migration
• For LAD Everytown
Population 100,000
Births 1,290
Deaths 870
Movers from elsewhere in UK 4,950
Movers to elsewhere in UK 4,950
Moves from overseas 830
Moves to overseas 550
Review of Current Method
PR t1 PR t2
LA 1
LA 2
Improvement Methods Under Review
There are three general themes for improvements we are looking at:
• Editing address details
• Better accounting for missed moves
• Using statistical modelling techniques
Improvement Case Study 1
Actual Move
PR
PopulationEstimates
2010(June)
2011(June)
2012(June)
John Smith22Nottingham
John Smith23Lambeth
John Smith24Lambeth
John Smith22Nottingham
Nottingham: 1 Lambeth : 0
John Smith24Lambeth
John Smith23Nottingham
Nottingham: 0 Lambeth : 1
Nottingham: -1 Lambeth : 2
Census(March)
Improvement Case Study 1
0
10
20
30
40
50
60
70
80
1,500 1,000 500 0 500 1,000 1,500
Males (2011 census based MYE) Females (2011 census based MYE)
Rolled Forward MYE
Improvement Case Study 1
Actual Move
Adjusted PR
PopulationEstimates
2010(June)
2011(June)
2012(June)
John Smith22Nottingham
John Smith23Lambeth
John Smith24Lambeth
John Smith22Nottingham
Nottingham: 1 Lambeth : 0
John Smith24Lambeth
John Smith23Lambeth
Nottingham: 0 Lambeth : 1
Nottingham:0 Lambeth : 1
Census(March)
Improvement Case Study 1
Matching PR with 2011 Census and using the Census address where they differ
• The PR 2011 was adjusted where required with Census address details, with later years of PR data similarly adjusted where the address has still not been updated
• Comparisons made to highlight numbers of moves between original and adjusted PRs
Improvement Case Study 1
Outflows from adjusted and unadjusted PR for 2012 and 2013
Inflows from adjusted and unadjusted PR for 2012 and 2013
Improvement Case Study 1
• Net migration from adjusted and unadjusted PR – 2012 and 2013
Improvement Case Study 2
• Current method uses PR or HESA address information based on which source appears to be the most up-to-date
• Interactions between the data sources can result in the overestimation of LA outflows for students aged 20-21
• This improvement aims to reduce this overestimation by using only HESA based address information
Improvement Case Study 2 – LA Outflows
Improvement Case Study 2 – LA Inflows
Improvement Case Study 2 – LA Net Flows
Improvement Case Study 2
• LAs with a high student population such as Leeds, Bristol, Coventry and Sheffield show the same pattern as Manchester after the improvement
• The improvement had a very small impact in London Boroughs
• Leads to an improvement in the quality of the estimates along with simplifying the method
Improvement Methods Under Review
There are three general themes for improvements we are looking at:
• Editing address details
• Better accounting for missed moves
• Using statistical modelling techniques
Next Steps
• Future research will assess the feasibility and likely impact of the proposed improved methods
• Research stage to be completed by Spring 2015
• Implement any methodological changes when the mid‐2015 England and Wales local authority based population estimates are published in June 2016
• Create revised back series to 2011
Discussion Questions
• Do you have any thoughts about how the improvements being proposed could impact on your local areas?
• How does internal migration affects your area and what data do you use to get information on internal migration
• Any other comments?