New Zealand Regional Intercensal Migration Estimates - 1981 to 2001

1. New Zealand Regional Intercensal Migration Estimates - 1981 to 2001 James Newell Monitoring and Evaluation Research Associates (MERA) & Richard Bedford University of Waikato Population Association of New Zealand 2005 Conference 1st July 2005

2. Outline • Background and Context to the Work • Validation Checks on the Net (International) Migration Estimates • Illustrate the character of some of the sorts of results with some graphs • International Migration flows by age • International Migration flows by gender • Net Internal Migration Flows by Ethnic Group

3. Project Outline • Extends the 1986 to 1996 Regional Migration estimates (Newell, 2002 refers) • Supported by a small research grant under the FRST New Demographic Directions Programme • Extends the earlier estimates to 1981 – 2001 • Analyses 1981 to 2001 births and deaths statistics to prepare custom life tables used to estimate net migration and international out migration components • Results replicate and extend regional migration statistics published in Newell (2002)

4. Estimation of Regional Migration • Grouped Territorial Local Authorities to best fit to regions (TARegions) • Actual historical local births by age of mother and deaths series applied to estimate vitals models and intercensal births and deaths • Pre-1990 vitals data involved regrouping urban area estimates to “regions” • This generation of work has focused at the local authority level and was prepared in the main at the single year of age level and later aggregated to five year of age groupings • The limitation to presenting the results at local authority rather than “regions” were • Insufficient time and resources to refine the method used to adapt the urban area based pre-1990 vital statistics to local authorities - regions were easier to work with • Local authority too detailed to present in this paper and useful to emulate the earlier published regional estimates • National net international migration results compared with an external control as a validation check

5. Comparing Intercensal Net International Migration Transitions

6. Adjustments for Comparability with Net Permanent Long Term International Migration Estimates

7. Difference from Net Permanent Long Term International Migration Estimates

8. Conclusions on the Checks • 1986 to 2001 results very comparable with Net Permanent Long Term Migration Estimates • Differences of net international migration flow estimates for regions less than 10% of outward flows • Big improvement on previous estimates • Can improve estimates by adjusting for net census undercount 1996-2001 and for unspecified origin region • Suggests that would be useful to triangulate analysis of census derived migration with net permanent long term migration flows data

9. Results

10. 1981 to 2001 Intercensal International Migration Transitions

11. Aggregate Migration Indicators

12. Features of International Migration Transitions 1981 - 2001 • Increasing Inward International Migration Flows over Time • Big variation up and down in international outward migration flows • Need to separate out in and out flows of New Migrants from return flows of New Zealanders • Need to extend the migration estimates to NZ Born / not NZ Born • Internal “inter-regional” migration flows slowly increasing

13. Regions in top half of Net Migration Rates 1996-2001

14. Regions in bottom half of Net Migration Rates 1996-2001

15. International Migration Flows by Age

16. Net International Migration Gain by Age Group

17. International Outward Migration Flow Rate by Age 1981 to 2001

18. International Inward Migration Flow Rate by Age 1981 to 2001

19. International Migration Flows by Gender

20. 1991-1996 International Migration Flows by Sex

21. 1996-2001 International Migration Flows by Sex

22. Net Internal Regional Migration Flows by Ethnic Group

23. Net Inter-regional Migration to the Northland Region by Ethnic Group

24. North Island - Net Inter-regional Migration Estimates – Maori vs European Maori European

25. North Island - Net Inter-regional Migration Estimates – Pacific Island vs Asian Pacific Island Asian

26. Where to from here? • Pragmatic adjustment for high 2001 census undercount • Would be useful to adjust the 2001 population data for the estimated net difference in the undercount between 1996 and 2001 and then rework the 1996 to 2001 intercensal migration transition estimates • Extend to 1976-81 • Results can be extended to include the 1976-81 period once comparable 1976 regional population estimates have been developed from the 1976 census masterfile and estimates prepared for pre-1981 regional vital statistics • Estimate pre-1990 local authority vital statistics • Refine the pre-1990 vital statistics to develop local authority level vital statistics - an ethnic vitals model will be needed to achieve a robust disaggregation of urban area vitals data

27. Where to from here? • An ethnic migration model • An ethnic population migration model considered important and all of the statistics prepared so far have been developed towards that end. Nightmare of low comparability of 1991, 1996 and 2001 ethnic population estimates to be grappled with • Extend the local authority level migration model to 1981-1991 • A local authority currently only fully specified for 1991-96 and 1996-2001 due to the limitations of vitals series • Disaggregate the estimates by NZ Born / not NZ Born • Important to distinguish the international migration flows of NZ Born / not NZ Born. • Would distinguish in and out flows of students as temporary residents • Help to understand and predict better the international out migration and return migration flows of New Zealanders as distinguish from permanent and long term migration inflows