Abstract
While population forecasters place considerable emphasis on the selection of appropriate migration assumptions, surprisingly little attention has been given to the effects on projection outcomes of the way internal migration is handled within population projection models. This paper compares population projections for Australia's states and territories prepared using ten different internal migration models but with identical assumptions for fertility, mortality and international migration and with the internal migration model parameters held constant. It is shown that the choice of migration model generates large differences in total population, geographical distribution and age-sex composition. It is argued that model choice should be guided by balancing model reality with practical utility and model performance is examined against these criteria. Of the ten models evaluated the authors argue that the migration pool, biregional, and biregional with net constraints models offer a good compromise between conceptual rigour and practicality. If the projected origin-destination flows are required then one of the versions of the standard multiregional model with reduced data inputs is preferred. The large variation in projection outputs points to the need for a better understanding of the spatio-temporal structure of migration in Australia.
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References
Australian Bureau of Statistics (ABS). 1995. Demographic estimates and projections: concepts, sources and methods. ABS catalogue no. 3228.0.
Australian Bureau of Statistics (ABS). 2003a.Population Projections, Australia: 2002 to 2101. ABS catalogue no. 3220.0. Canberra.
Australian Bureau of Statistics (ABS). 2003b. Net overseas migration: adjusting for actual duration of stay or absence.ABS Demography Working Paper 2003/05. Canberra.
Bell, M. 1992.Demographic Projections and Forecasts in Australia: A Directory and Digest Canberra: Australian Government Publishing Service.
Burch, T.K. 2003. Demography in a new key: a theory of population theory.Demographic Research 9: 263–284. <www.demographic-research.org>.
Courgeau, D. 1995. Migration theories and behavioural models.International Journal of Population Geography 1: 19–27.
Feeney, G. 1973. Two models for multiregional population dynamics.Environment and Planning 5: 31–43.
Government Actuary's Department (GAD). 2002.National Population Projections: 2000-based. Series PP2 no. 23. London: TSO.
Hinde, A. 1998.Demographic Methods. London: Arnold.
Isserman, A.M. 1985. Economic-demographic modeling with endogenously determined birth and migration rates: theory and prospects.Environment and Planning A 17: 25–45.
Isserman, A.M. 1993. The right people, the right rates: making population estimates and forecasts with an interregional cohort-component model.Journal of the American Planning Association 59: 45–64.
Jackson, N. and R. Kippen, 2001. Wither Tasmania? A note on Tasmania's population problem.People and Place 9(1): 27–37.
McDonald, P., S. Khoo, and R. Kippen. 2003. Alternative net migration estimates for Australia: exploding the myth of a rapid increase in numbers.People and Place 11(3): 23–36.
McDonald, P. and R. Kippen. 2002. Projecting future migration levels: should rates or numbers used?People and Place 10(1): 82–83.
Nair, P.S. 1985. Estimation of period-specific gross flows from limited data.Demography 22: 133–142.
Office of the Deputy Prime Minister (ODPM). 2002.Development of a Migration Model. London.
Plane, D.A., 1993. Requiem for the fixed-transition-probability migrant.Geographical Analysis 25: 211–223.
Plane, D.A. and P.A. Rogerson. 1985. Economic-demographic models for forecasting interregional migration.Environment and Planning A 17: 185–198.
Plane, D.A. and P.A. Rogerson. 1986. Dynamic flow modeling with interregional dependency effects: an application to structural change in the US migration system.Demography 23: 91–104.
Plane, D.A. and P.A. Rogerson. 1994.The Geographical Analysis of Population with Applications to Business and Planning. New York: John Wiley.
Preston, S.H., P. Heuveline and M. Guillot. 2001.Demography: Measuring and Modeling Population Processes. Oxford: Blackwell.
Ravenstein, E.G., 1885. The laws of migration.Journal of the Statistical Society 48: 167–235.
Rees, P.H. 1981. Accounts based models for multiregional population analysis: methods, program and users' manual.Working Paper 295/Computer Manual 13. School of Geography, University of Leeds.
Rees, P.H.. 1986. Choices in the construction of regional population projections. Pp. 126–159 in R. Woods and P.H. Rees (eds),Population Structures and Models: Developments in Spatial Demography. London: Allen and Unwin.
Rees, P.H. 1989. Old model faces new challenges: a review of the state of the art in multistate population modelling.Working Paper 531, School of Geography, University of Leeds.
Rees, P.H. 1994. Key issues in sub-national population projection models.Working Paper 94/8, School of Geography, University of Leeds.
Rees, P. 1997. Problems and solutions in forecasting geographical populations.Journal of the Australian Population Association 14: 145–166.
Rees, P.H. and O. Duke-Williams. 1997. Methods for estimating missing data on migrants in the 1991 British Census.International Journal of Population Geography 3: 323–368.
Rees, P., M. Kupiszewski, H. Eyre, T. Wilson and H. Durham. 2001.The Evaluation of Regional Population Projections for the European Union. Eurostat Working Paper 3/2001/E/no.9. Luxembourg: Office for the Official Publications of the European Communities.
Rees, P.H. and F. Willekens. 1989. Population projection: Dutch and English methods. Pp. 19–37. in J. Stillwell and H.J. Scholten (eds),Contemporary Research in Population Geography: A Comparison of the United Kingdom and the Netherlands. Dordrecht: Kluwer Academic Publishers.
Rees, P.H. and A.G. Wilson 1973. Accounts and models for spatial demographic analysis 1: aggregate population.Environment and Planning 5: 61–90.
Rees, P.H. and A.G. Wilson. 1977.Spatial Population Analysis. London: Edward Arnold.
Rogers, A. 1966. Matrix methods of population analysis.Journal of the American Institute of Planners 32: 40–44.
Rogers, A. 1975.Introduction to Multiregional Mathematical Demography. New York: John Wiley.
Rogers, A. 1976. Shrinking large-scale population projection models by aggregation and decomposition.Environment and Planning A 8: 515–541.
Rogers, A. 1990. Requiem for the net migrantGeographical Analysis 22: 283–300.
Rogers, A. 1995.Multiregional Demography: Principles, Methods and Extensions. Chichester: John Wiley.
Rogers, A. and F. Planck. 1983. MODEL: a general program for estimating parameterised model schedules of fertility, mortality, migration, and marital and labor force status transitions.HASA Working Paper WP-83-102.
Rogers, A., R. Raquillet and L.J. Castro. 1978. Model migration schedules and their applications.Environment and Planning A 10: 475–502.
Rowland, D.T. 2003.Demographic Methods and Concepts. Oxford: Oxford University Press.
Smith, S.K. 1986. Accounting for migration in cohort-component projections of state and local populations.Demography 23: 127–135.
Smith, S.K. and M. Shahidullah. 1995. An evaluation of population projection errors for census tracts.Journal of the American Statistical Association 90 (425): 64–71.
Smith, S.K. and T. Sincich. 1992. Evaluating the forecast accuracy and bias of alternative population projections for states.International Journal of Forecasting 8(3): 495–508.
Smith, S.K., J. Tayman and D.A. Swanson. 2001.State and Local Population Projections: Methodology and Analysis. New York: Kluwer Academic.
Statistics New Zealand. 2003. Sub-national population projections; technical notes. <www.stats.govt.nz/>. Accessed 14 November 2003.
Stillwell, J. 1986. The analysis and projection of interregional migration in the United Kingdom. Pp. 160–202 in R. Woods and P. Rees (eds),Population Structures and Models: Developments in Spatial Demography. London: Allen and Unwin.
Tayman, J. and D.A. Swanson. 1996. On the utility of population forecasts.Demography 33(4): 523–528.
van der Gaag, N., E., van Imhoff and L. van Wissen. 1997. Long-term internal migration scenarios for the countries of the European Union.Eurostat Working Paper E4/1997-5.
van der Gaag, N., E. van Imhoff and L. van Wissen. 2000. Internal migration scenarios and regional population projections for the European Union.International Journal of Population Geography 6: 1–19.
van Imhoff, E., L. van Wissen and K. Spiess. 1994.Regional Population Projections in the Countries of the European Economic Area. Lisse: Swets and Zeitlinger.
van Imhoff, E., N. van der Gaag, L. van Wissen and P. Rees. 1997. The selection of internal migration models for European regions.International Journal of Population Geography 3: 137–159.
Willekens, F. 1999. Modeling approaches to the indirect estimation of migration flows: from entropy to EM.Mathematical Population Studies 7: 239–278.
Willekens, F.J. and P. Drewe. 1984. A multiregional model for regional demographic projection. Pp. 309–334 in H. ter Heide and F.J. Willekens (eds),Demographic Research and Spatial Policy: the Dutch Experience: London: Academic Press.
Wilson, A.G. 1971. A family of spatial interaction models, and associated developments.Environment and Planning 3: 1–32.
Wilson, T.G. 2001. A new sub-national population projection models for the United Kingdom. PhD thesis, School of Geography, University of Leeds.
Wilson, T. and M. Bell. 2004. Australia's uncertain demographic future.Demographic Research 11-8.<www.demographic-research.org>.
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Wilson, T., Bell, M. Comparative empirical evaluations of internal migration models in subnational population projections. Journal of Population Research 21, 127–160 (2004). https://doi.org/10.1007/BF03031895
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DOI: https://doi.org/10.1007/BF03031895