1. Applying model migration schedules to represent age-specific migration flows
James Raymer
University of Southampton
Andrei Rogers
University of Colorado
Paper prepared for presentation at The Third International Population Geographies Conference, Liverpool, June 2006

2. Outline Research question and significance
The multiexponential model migration schedule
Age-specific patterns of migration in the U.S. West
Application of model migration schedules to represent age-specific migration flows
Some results
Summary and discussion

3. Research question and significance
How can known regularities of age-specific migration be better used to estimate migration flows?
Significance
Age-specific data are needed for planning and understanding patterns
Often these data are incomplete or not available

4. The Rogers-Castro (standard) multi-exponential model migration schedule
Model schedules are used to:
Identify regularities
Smooth irregular data
Infer missing data
Represent unknown age profiles
Rogers A and LJ Castro. 1981a. Model migration schedules. RR-81-30, International Institute for Applied Systems Analysis, Laxenburg, Austria.

5. The four main families of multiexponential model migration schedules

6. Age profiles of U.S. interstate migration and immigration, 1985-1990
Aim: develop a method for obtaining estimates of age-specific migration flows given various levels of incompleteness in the data
Key assumption: aggregate migration levels are known

7. 196 age profiles
Model migration schedule of observed age profiles of migration in the U.S. West,

8. The four age profiles of interstate migration in the U. S
The four age profiles of interstate migration in the U.S. West,

9. 118 age profiles
34 age profiles
35 age profiles
9 age profiles
Model migration schedules of observed standard, young standard, old standard, and elderly retirement age profiles of migration in the U.S. West,

10. Model migration schedules (standardized to unit area) of observed age profiles of migration in the U.S. West,

11. Comparison of different age-specific models used to predict age profiles of interstate migration in the U.S. West,

12. Comparison of different age-specific models used to predict age profiles of migration from California to Arizona, Colorado, Montana, and Utah,

13. The observed and predicted migration flows from California to Arizona, 1985-1990

14. The observed and predicted migration flows from California to Colorado, 1985-1990

15. The observed and predicted migration flows from California to Montana, 1985-1990

16. The observed and predicted migration flows from California to Utah, 1985-1990

17. Summary and discussion
Four age profiles of migration were used to represent 196 flows
Can extensions can be made to other contexts?
Intercensal survey data
International migration between countries in the EU
Less developed nations
Future work involves identifying key factors that explain different age profile shapes