1. The role of international migration in population forecsts
Rainer Münz
NTTS 2017
Satellite Event
Challenges in Migration Statistics
Brussels, March 13, 2017
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2. Demographic projection
Starting point: Known/assumed size and structure (age, gender) of a population at a particular moment in time
Size and structure „multiplied“ by
Fertility
Mortality
Spatial mobility
Spatial mobility includes
Immigration
Emigration (at different levels: regional, national, continental)
At a global level: Immigration = Emigration

3. Immigration/emigration numbers are not shown
Europop: Projected number of births/deaths with and w/o migration, EU-28, 2015–2080 (millions)
Immigration/emigration numbers are not shown

4. Forecasting Europe‘s Population
Europop: Actual and projected population by age, EU-28, 2014–2060 (in %)
Forecasting
Europe‘s Population

5. Behavioural components
Person based complex indicator
Behavioural components
Fertility
Basis: all births
Indicator: Age specific fertility rates (TFR)
Mortality
Basis: all deaths
Indicator: Age specific mortality rates (based on life tables)
Spatial mobility
Basis: ideally all changes of residence accross borders (often unknown)
Indicator: Net migration (rates)
Alternative: Average number of movements a person will experience during his/her life time.
Population based; less complex than TFR + life tables

6. Challenges
Migration much less well understood than fertility/mortality
Measured in different ways accross Europe
Measured not at all in many sending countries

7. Two types of „errors“ 1) People who are present, but not registerd
Irregular migrants (irregular entry, overstayers)
Foreign students, scholars, seasonal labour
2) People who are registerd, but not present
Emigrants who did not deregister (negligence, on purpose, political spin)
People who die abroad without authorities being notified

8. Our „work around“
Net migration

9. Our „work around“ Net migration
Defined as: „the difference between immigration to and emigration from a given area during the year.
Since many countries either do not have accurate figures on immigration and emigration, or have no figures at all, net migration has to be estimated.
It is usually estimated as the difference between the total population change and the natural increase during the year.
Net migration gives no indication of the relative scale of the separate immigration and emigration flows to and from a country.“

10. Our „work around“ Net migration Estimating net migration
Based on incomplete data
Based on the residual method
Main comceptual deficit:
- Net migrants do not exist

11. Existing population projections combine:
highly sophisticated models on fertility, mortality and demographic aging
with a much less sophisticated approach to migration.
For many years migration, especially in the field of international population projections, has been treated as some sort of “foster child”.

12. Requiem?
No. 1: In 1990, Andrei Rogers wrote a requiem for “net migrants, a nonexisting category of individuals”
No. 2: In 1993, David Plane proposed burying the fixed-transition-probability migrant (1993). Plane argued that, although migration in multiregional models is formulated as flows, it assumes constancy of emigration rates (formulated as fixed transition probabilities).
Assumption: no interaction between sending and receiving countries or regions.

13. Requiem? Reality in 2017: Concept of net migration still widely used
And where this is not the case:
Scholars still love the “beauty” of stationary multiregional models with fixed transition probabilities.
They allow for concise mathematical analysis with attractive solutions.

14. Comparison of net migration estimates and projections, 1950-2100

15. Why does this matter?

16. Migration balance more important than natural balance
Europop: Projected developments of population change components, EU-28, 2015–2050 (thousands)
Migration balance more important than natural balance

17. USCB: Contribution of immigrants and their offspring to US population, 1970-2050 (millions)
Cumulative effect

18. USCB: Projected population of the US, 8 migration scenarios, 2010–2100 (millions)

19. Eurostat: Projected population of EU28, France, Germany and the UK with and w/o migration, 2014–2080 (Index 2014 = 1)
Source: Eurostat

20. Addressing incomplete data
Working on improved data collection
EU: harmonised definition
Alternative data sources (for example: mobile phone data, remittances)

21. Replacing net migration in projections
Calculating and projecting immigration and emigration separately
At international scale: Reconciling immigration and emigration

22. Way forward
Projecting the population with immigrant background separately
Age
Gender
Countries of origin/destination

23. Age structure of immigrants by citizenship; 3rd country nationals vs
Age structure of immigrants by citizenship; 3rd country nationals vs. naturalised immigrants, EU28, in % of total population
Like a separate region
Source Eurostat

24. Way forward By default:
Estimating the size of recent flows from structure and changes in stock

25. Stock of international migrants by origin and destination, 2015
Oceania
Northern America
Africa
Latin America
Asia
Wider Europe
Source: Abel and Sanders based on UN Pop. Div.

26. Problem: immigration is better documented than emigration
Assumptions for projection
Intensity of future migration
Affected age groups
Geographic distribution
At global level: Net flow needs to stay at zero
Problem: immigration is better documented than emigration

27. Africa vs. Europe Population 1950-2100
1995
Constant rates?
Source: UN Pop. Div., WPP

28. The number of international migrants grows not much quicker than the world population
Absolute numbers and proportion of migrants in total population
But!
The number of international migrants has two different determinants:
The intensity of cross-border mobility
The number of sovereign states
1990
2000
2010
2015
Source: UN Population Division

29. What drives international migration?

30. Data Analysis Data Analysis What matters most:
Size of migrant networks (resulting from past migration)
Economic attractiveness
Geographical proximity
Cultural proximity
Civil wars, violent conflicts
What does not matter (so far):
Demographic pressure

31. A better understanding of the dynamics cannot not replace plausible scenarios

32. Will international migration continue at present levels?
Final question:
Will international migration continue at present levels?
Will it increase?
Or decrease?

33. Above income levels of US-$ 13,000 per capita: net-emigration stops Annual average net migration per 1000 inhabitants ( )
GDP per capita in 2013
Net migration per 1000 inhabitants
Data Source: UN; Muenz & Reiterer

34. Above income levels of US-$ 13,000 per capita: net-emigration stops Annual average net migration per 1000 inhabitants ( )
Data Source: UN; Muenz & Reiterer

35. The relation between development and migration is not linear Emigration vs. immigration by GDP per capita
Source: P. Martin, H. de Haas

36. 400 years of net emigration 33 years of net immigration
Europe between emigration and immigration: The main direction changed only recently Immigration minus emigration (= net-migration),
400 years of net emigration
33 years of net immigration
Source: Eurostat

37. The number of international migrants is projected to increase further
Absolute numbers and proportion of migrants in total population
growth rate
growth rate
growth rate
1990
2000
2010
2015
2030
United Nations/Population Division

38. Net migratory flows to the USA 1950-2010 (actual), 2015-2100 (different projections), in mn
Gravity model
Linear
model
UN WPP 2015
projection
TRUMP
UN WPP 2010
projection xx xx

39. Convergence assumption for Europop projections
Source: Lanzieri 2008

40. Europop migration modelling at sub-national level
Trend towards equilibrium between inflows and outflows
Consideration of competition with other poles of attraction
Population ageing
Some adjustment for shrinking working populations
Projection output: net migration rates at NUTS 1, NUTS 2, NUTS 3 level
Source: Lanzieri 2016

41. Europop: Projected population change due to net migration, NUTS 2 level, 2015–50 (%)
Change in %

42. Europop: Projected developments of population change components, EU-28, 2014–2080 (thousands)

43. What speaks infavour of declining migration?
Assumption of increasing converence
Uncertainty

44. What speaks in favour of continuing migration?
Assumption of lasting disparities
Common sense expectatons

45. … so, we need to make a choice

46. Thank you! rainer.munz@ec.europa.eu
Regagner le contrôle des frontières européennes: une solution globale pour la Gestion des Frontières Externes de l'UE
Reprendre contrôle des frontières européennes: une solution globale pour la Gestion des Frontières Externes de l'UE
Rétablir un contrôle des frontières européennes: une solution globale pour la Gestion des Frontières Externes de l'UE