Moving earth, moving people – population .. migration impacts of the Canterbury Earthquakes

1. Moving earth, moving people – population .. migration impacts of the Canterbury Earthquakes Joining some of the dots on the story so far James Newell, MERA (Monitoring and Evaluation Research Associates Ltd) An updated and annotated version of the PowerPoint used for April 26th, 2012 Seminar (this version has any edits up to May 1st 2012)

2. Picking up some of the threads from .. • Three professional meets - November 2011 • Population and Employment Effects of the Christchurch Earthquakes … workshop… Lincoln University • “Natural Disasters : Impact Assessment for Sustainable Recovery” – NZ Association for Impact Assessment 2011 Conference - Lincoln University • 2011 Population Association of NZ Conference – Auckland University

3. Picking up the threads from November conferences .. • NZAIA conference – local follow up called for – Dr Nick Taylor leads this for NZAIA • NZAIA with Canterbury Health organised this seminar … asked me to present some of my work • Present some results from population monitoring - as food for discussion • first in a seminar series? • Sharing work / discussion of impacts and associated management in the recovery process … • NZAIA has set up a web forum and 2011 conference & workshop archive – • www.impactsforum.weebly.com

4. The work presented here … • Picks up from the “Population.. Effects” workshop • Clear that the workshop skimmed the surface and understanding migration / population effects of the EQ a work in progress – very live • Inspiration / motivation • Discussion with David Johnston (Centre for Disaster Research / GNS Science) and Sarah Beaven (Social Science liaison – Natural Hazards Platform) • Needed at least to document, digest, disseminate content of the November 2011 workshop

5. In writing up the workshop – clear that • A lot of spade work needed to make sense of the evidence, estimates and future expectations on migration and population • Incomplete and a lot of useful information not included in November • Much of the evidence not connected • Not analysed except superficially • Assumptions not stated – needed to be drawn out • … much of the evidence only just coming available

6. Where I am coming from? • More than 25 years hands on local “at the coal face” experience with • Population estimates and forecasting models • Urban growth models for local government • Special interest in understanding migration flows • within and between regions • international migration flows (university research projects, science programmes, international studies and operational models for central and local government • Labour and educational capital flows – especially trans Tasman • Labour market studies / employment patterns – employment, occupational and industry trends • demographic groups and communities

7. So …. over the last four to five months… • Collate / collect / analyse more carefully the evidence • Draw out the assumptions behind the estimates and explore the ramifications of those estimates • explore the future implications – integrate into existing and updated future scenarios • Document / write-up the results into an updated and extended state of play… • initial discussions on the draft results / conclusions

8. .. In detail • Raw data– the raw evidence base, metadata, statistics, LIS layers …. • Estimates – conversions and adjustments to raw statistics into standardised measures and our best guesses on any derived statistics and population parameters • Systems – models for integrating the estimates to address end uses including derived statistics • Forecasting tools – local authority level cohort component computer software programme that replicates SNZ tla population projections and linked household formation and labour force projection models • Expectations - current and some partially updated future and resulting future population scenarios

9. For this seminar • At its base – very technical– masses of statistics, models, estimates, many stories • Far too much to fit into a 45 minute session • At one level some very complex technical work on statistics, estimates, models … • Picking out a few key results around some key questions

10. What we .. know – the evidence base – recent past / now … official and admin statistics (records) best guesses - of the past / now … … estimates “predict” – future expectations … projections (scenarios)

11. People moves - after the earth moved .. What we know – the evidence base … official and administrative statistics What we think we know … our best guesses … estimates and assumptions behind those What we think is likely to happen in the future projections / scenarios / predictions

12. Major part of this is the refinement of an existing subnational population accounting model Red components are derived by combining others Blue components are based on MERA custom series

13. In practice – it combines.. • Top down • Official and other summary statistics and surveys • Vital statistics (births and deaths), external migration movements, building consents, population estimates … • Bottom up • Operational and administrative records • School roll returns by school .. Ece … • Property records and assessments..

14. Why is understanding population important? • Large short term and medium term changes in • population size, composition and distribution • Major decisions in terms of reinvestment with long term implications need to be made • Schools, Roads and other infrastructure, business location … • Information important for public and private sector interests • An major urban centre is a cloth woven around • its population • its settlement pattern • associated public and private land uses

15. People, homes, land, jobs …

16. The focus here is “regional” • Focussed mainly on the “strategic level” • Is “Greater Christchurch” • Christchurch City, Waimakariri Di, Selwyn Di) • Includes some localised meshblock, area unit, ward results to inform the “strategic picture” • Understanding population and migration is “layered” at different geographic levels • Nation – region – local authority – neighbourhood / suburb • At very local neighbourhood level – have regional effects and processes • but also other processes not mirrored at a “regional” level

17. Questions : methods/tools/systems, evidence/estimates/scenarios • Migration and population effects so far? • Need to see recent post 2006 and post EQ trends in a historical context • Who has/is moving and where? • Need to use a formal population accounting framework • What does this suggest for the future growth path? • Projection scenarios old and new

18. What do we know about population and migration change (since 2010)? • We only have estimates • Statistics NZ for June year population • 5 years + since the last population census • 2011 census a casualty of the February 2011 census • Next census in 2013 – results in 2014? • 2006 to 2012 – huge changes in jobs and migration – where are we now?

19. Canterbury 2010/2011 EQPopulation migration effects in context …

20. Some crude comparative statistics - Part 1Adapted in part from : Beaven & Pearson 2011

21. Some crude comparative statistics - Part 2Adapted in part from : Beaven & Pearson 2011

22. What effect has the EQ had on migration? …

23. Changes in rate of population growth

24. Components of the change in population for the 2010/2011 June Year

25. Estimated migration and changes in migration 2010/2011

26. Estimated change in internal migration rates for 2010/2011

27. Implied / Indicative Distribution of net internal migration “earthquake refugees” from Christchurch City over the June year

28. How does estimated migration for 2010/2011 compare with indicators of migration for 2011/2012? Some Indicators

29. Checks on SNZ estimates? • School rolls • a good source of updated local population estimates of children • Use the 2010 and 2011 rolls to estimate migration by age • Compare with estimated net migration implied in the SNZ estimates

30. Estimates of the Rate of Net Migration loss (%) for Greater Christchurch over the year to June 2011

31. Estimated net migration of 6 to 9 yr olds based on school rolls

32. Why a difference from SNZ estimates? • SNZ estimates - a lower bound for estimates of net migration loss of children and families over 2010/2011? • July 2011 school rolls came out after the estimates • Caution though ….. • Children may have been sent away “temporarily” with one of more parent remaining in Canterbury • Rolls include some people who are not permanent residents

33. Overall numbers are one thing – but compositional changes are larger …

34. Net decrease in the Christchurch City Population by age and sex - June 2011 Year

35. Greater Christchurch net migration for the June 2011 year by age for selected ethnicities estimated from changes in school enrolments

36. Estimated net change in Household Types in Christchurch City inferred from Statistics NZ population estimates

37. Some drivers of migration losses Physical damage and rezoning of land and property Loss of Jobs (temporary / permanent)

38. Christchurch CBD Exclusion Zone Effect

39. Jobs, Population and Households in the CBD Exclusion Zone (2006)

40. Industry Profile of CBD Excl Zone Jobs (2006)

41. Residential Land Use Impact Indicators • e.g. Percent of land area zoned “red” or “orange” • Implied number of households vacated? Sum of (red) or discouraged (orange)? • Estimated net number of households lost • Meshblock level distribution of red and orange zone land units • Ward and Area Unit level summary

42. Central Christchurch - % red zoned

43. Kaiapoi – percent red zoned..

44. Translating Population effects into households and families …

45. Modelled loss or gain of households • e.g. Percent of land area zoned “red” or “orange” • Implied number of households vacated? Sum of (red) or discouraged (orange)? • Estimated net number of households lost • Meshblock level distribution of red and orange zone land units • Ward and Area Unit level summary

46. Estimated net change in Household Types in Christchurch City inferred from Statistics NZ population estimates

47. Estimated 2010 – 2011 change in occupied private households in Christchurch City by Area Unit

48. Estimated 2010 – 2011 change in number of occupied private households in Kaiapoi by Area Unit

49. How much momentum has the recovery got so far? Some useful indicators … Value of Building permits Estimated “effects” on “long term” international migration

50. Estimated month by month reduction of Christchurch City population from EQ effects on international migration flows by direction of flow