Global Economy and BusinessMOBILITY AND MIGRATION

• Prof.ssa Luisa Natale• http://www.docente.unicas.it/

luisa_natale/

• email oli59@mclink.it

MOBILITY AND MIGRATION

4a. MEASURES

Measures

The study of migration focuses on:

A)Intensity (absolute values, rate, …)

B)Distance and direction of flow - that is, specifying the origin and destination of the migration flows

C) The structure of the migrant population according to the main features of biodemographic, socio-economic, ethnic and cultural type

A) Intensity of migration Estimate of NET MIGRATION

Net total of migrants during the period, that is, the total number of immigrants less the annual number of emigrants, including both citizens and noncitizens

NET MIGRATION ESTIMATE

A. Direct estimateFor example: Equation of Population: Italy 2010 (slide

6)Source →//demo.istat.it/index.html→ Bilancio demografico 2010

B. Indirect estimate

Total Population Balance

nPt = nPt-1+nB∆t - nD∆t +n I∆t - nE∆t

B = birthsD = deaths I = Immigration E = Emigrationt = time, n = type of population (in this case, total

population)

nB∆t - nD∆t = Natural Increase

n I∆t - nE∆t = Net Migration

Total Population Increase

•nPt - nPt-1 = Total population increase

•nPt - nPt-1= nB∆t - nD∆t +n I∆t -

nE∆t

• This is the classical definition of a population balance

The real population balance

• In countries with census and population registers, the balance is not merely a result of natural and migration increase

• Other components are present in a balance (see, for instance, Italy)

The two population balances

• nPt - nPt-1= nB∆t - nD∆t +n I∆t - nE∆t

the classical population balance

• nPt - nPt-1= nB∆t - nD∆t +n I∆t - nE∆t + n OI∆t -

nOE∆t + n IntI∆t - nIntE∆t

n OI∆t - nOE∆t = other registered/cancelled

(n IntI∆t - nIntE∆t )= total internal balance

the real population balance (see Italy)

The internal migration balance (n IntI∆t - nIntE∆t )= total internal balance

= enrolled from others municipalities-cancelled to other municipalities

It should be egual to zero, but due to late in the

process of registration/deregistration of flows in each

municipalities the balance is always different from

zero (often fifty-sixty thousands of movements, very

scarce in comparison of 1,3 millions of internal

movements)

EXERCISE

•Write: • 1) the Equation of total population in

Italy, 2010, 31.12 (Direct

estimate ,slide 12) • 2) total population increase (Direct

estimate, slide 12)

TOTAL POPULATION BALANCE

A. Direct estimate (Italy, 2010)Population and flows Males Females Total

Population at 1° January 2010 29,287,403 31,052,925 60,340,328

Births 289,185 272,759 561,944

Deaths 286,094 301,394 587,488

Natural increase 3,091 -28,635 -25,544

Enrolled from other municipalities

684,294 690,069 1,374,363

Enrolled from abroad 207,720 251,136 458,856

Other registered 25,830 14,210 40,040

Cancelled to other municipalities

677,372 686,042 1,363,414

Cancelled to abroad 42,037 36,734 78,771

Other canceled 75,655 43,761 119,416

Net migration (comprised other flows)

122,780 188,878 311,658

Population at 31° December 2010

29,413,274 31,213,168 60,626,442

Net migration (not comprised other flows)

165,683 214,402 380,085

EXERCISE

• Natural Increase= nB∆t - nD∆t = 561944 – 587488 = -25544

• Net (International) Migration = Enrolled from abroad – cancelled to abroad = +n I∆t - nE∆t = 458856 – 78771= 380,085

• Technical balance n OI∆t - nOE∆t = other registered – others cancelled = 40040 – 119416 = - 79376

(n IntI∆t - nIntE∆t )=total internal balance=1374363-1363414=10949

Other components (net migration due to other reasons):-79376 – 10949 = - 68,427

Net Migration (other reasons compr.): 380085 – 68427= 311,658

Equation of Population: Italy 2010, 31.12  

60,626,442 = 60,340,328 +(-25,544)+ 311,658

where:Natural Increase: - 25,544Net (International) Migration: + 380,085Other components (net migration due to other

reasons): - 68,427Net Migration (other reasons compr.): +

311,658Total Increase: 60,626,442 - 60,340,328 =

286,114

FOREIGN POPULATION BALANCE

A. Direct estimatePopulation and flows Males Females Total

Foreign population at 1° January ‘10 2063407 2171652 4235059

Births 40257 37825 78082

Enrolled from other municipalities 109928 124262 234190

Enrolled from abroad 188,850 235,649 424,499

Other enrolled 13653 8619 22272

Total enrolled 352688 406355 759043

Deaths 2952 2172 5124

Cancelled to others municipalities 107440 121373 228813

Cancelled to abroad 15,670 17,147 32,817

Acquisition (naturalized) 32567 33371 65938

Other cancelled 56255 34838 91093

Total cancelled 214884 208901 423785

Foreign population at 31 December 2201211 2369106 4570317

Net migration (not comprised other flows)

173,180 218,502 391,682

Equation of Foreign population

Population Total Increase → fPt - fPt-1

fPt - fPt-1 = fBt - fDt + fIt - fEt - fNt +fOIt - fOEt +

+ fIntI∆t - nIntE∆t

B=births, D=deaths, I=Immigration, E=Emigration, N=NaturalizationO=technical adijustments, Int = internal moves; where:

fBt - fDt = Natural Increase

fIt - fEt = Net (International) Migration (enrolled from abroad-cancelled to abroad)

fOIt- fOEt =Technical balance (other enrolled-other cancelled)

fIntI∆t - nIntE∆t =Internal moves (enrolled from other municipalities - cancelled to others municipalities)

EXERCISE

Write: 1) the Equation of foreign population

in Italy, 2010, 31.12 (Direct

estimate, slide 12) 2) foreign population increase (Direct

estimate, slide 12)

Equation of Foreign population

fPt - fPt-1 = fBt - fDt + fIt - fEt - fNt +fOIt - fOEt +

+ fIntI∆t - nIntE∆t

B=births, D=deaths, I=Immigration, E=Emigration, N=NaturalizationO=technical adijustments, Int = internal moves; where:

fBt - fDt = Natural Increase = +72,958= 78,082 - 5,124

fIt - fEt = Net (International) Migration (enrolled from abroad-cancelled to abroad)= 424,499 - 32,817 = 391682

fOIt- fOEt =Technical balance (other enrolled-other cancelled)= 22272-91093 = - 68821

fIntI∆t - nIntE∆t =Internal moves (enrolled from other municipalities-cancelled to others municipalities) = 234190 – 228813= 5377

FOREIGN NET MIGRATION

ESTIMATE A. Direct estimate

•Net (International) Migration: + 391682

•Net Migration (other reasons compr.): +391682 – 68821 + 5377 = + 328238

Equation of Foreign Population(Italy 2010)

4,570,317 = 4,235,059 + 72,958 + 328,238 + (-65,938)

4,570,317 - 4,235,059 = + 72,958 + 328,238 - 65,938

335,258 = 335,258Total Increase = 335,258

Net Migration (other reasons compr.): +391,682 – 68,821 + 5,377 = +328238

Natural Increase = +72,958Naturalised = -65,938

Foreign population increase

(Italy 2010)

4570317 - 4235059 = +335258

Resident foreign population at 31 December and demographic balance from 9 October 2011 to 31 December 2011. Italy

M F Total

Foreign resident population at 9th october 1881639 2147506 4029145

Births 9515 9172 18687

Enrolled from others municipalities 26279 31665 57944

Enrolled from abroad 37064 40426 77490

Others enrolled 5745 4957 10702

Total enrolled 78603 86220 164823

Deaths 782 615 1397

Cancelled to others municipalities 26408 32367 58775

Cancelled to abroad 3597 4188 7785

Naturalizations 4756 5127 9883

Others cancelled 32530 29999 62529

Total cancelled 68073 72296 140369

Foreign population resident at 31th december 1892169 2161430 4053599

EXERCISE Calculate the equation of the foreign

population by distinguish each component

Foreign contribution to the increase

• During the 2010 (but the same happened in the previous years…) the total population increase in Italy could be disaggregated in two component:

-100000 -50000 0 50000 100000 150000 200000 250000 300000 350000 400000 450000

Total

Italian

Foreign

Net migration

Total increase

NET MIGRATION ESTIMATE

B. Indirect estimate

Estimation of net migration (nNMt)

by the availability of natural increase

(nBt - nDt) and population (type n)

in two points (nPt and nPt-1):

nNMt = nPt - nPt-1 – (nBt - nDt)

Example: Italy, 1992-2001

Population at 1 January 1992 = 56,773

Population at 1 January 2002 = 56,994

Total increase = + 223

Births (1992-2001) = 5,416

Deaths (1992-2001) = 5,592

Natural Increase = - 176

Net Migration = ?

Example: Italy, 1992-2001

Population at 1 January 1992 = 56,773

Population at 1 January 2002 = 56,994

Total increase = + 221

Births (1992-2001) = 5,416

Deaths (1992-2001) = 5,592

Natural Increase = - 176

Net Migration = 221 – (-176) = + 397

NET MIGRATION ESTIMATE

B. Indirect estimateWeakness• You can estimate only the balance

(no information about gross flows)• in the case of a sub-national area

you can estimate the internal balance + international balance

• weakness of the measurement in developing countries

1. Indirect estimate : Foreign Born Population

Case study Population balance equation bPt = bPt-1 - bDt + bIt - bEt then: bNM = bIt - bEt = bPt - bPt-1 + bDt “Reduced Equation” (… births are

lacking!)

2. Indirect estimate: Foreign Citizen Population

Population equation

fPt = fPt-1 + fBt - fDt + fIt -

fEt - fNt

Then: fNM = fIt - fEt = fPt –

fPt- - fBt + fDt + fNt

MIGRATION INTENSITY OF INFLOW AND OUTFLOW

1. Interested to both the migratory flows → in and out flow, gross flow and net flow

2. Standardisation by population consistency, age, sex … → gross rate, specific rate

Migratory flows → in and out flow, gross flow and net flow

Considers as (Boyle, Halfacree, Robinson, 1998)

• IMi = Gross In-Migration, the volume of in-migration moving into a place i

• OMi = Gross Out-Migration, the volume of out-migration moving from a place i

In this case Net Migration is defined as the algebraic sum of gross flows:

NMi = IMi - OMi (as in the previous slides…)

Standardisation by population consistency, age, sex … → gross

rate, specific rate

To allow comparison among different places or the same place over time the measures are standardized by dividing the volumes by the average population of the place, so obtaining a RATE

RATES

• IMRi = IMi / Pi x 1,000 that is in-migration rate

• OMRi = OMi / Pi x 1,000 out-migration rate

• NMRi = (IMi - OMi) / Pi x 1,000 net-migration rate

with Pi average population, that is the population on average counted during all the year (or during all the period)

Average population

A good approximation of this average population can be obtained:

a) using the population observed at the mid-term

b) using a semi-sum of the population at the initial and the final period considered.

Noting that in the case in which the observation of flows is made across a non-year period (for example, more than one year) the calculus must take into account this odd temporal reference.

The crude migration rate: an example

Total Population (Italy, 2010) Foreign Population (Italy, 2010)

1 January 60340328 1 January 4235059

31 December 60626442 31 December 4570317

Average (1) 60483385 Average (1) 4402688

Immigration (2) 458856 Immigration (2) 424499

Emigration (3) 78771 Emigration (3) 32817

Net Migration (4) 380085 Net Migration (4) 391682

Immigration Rate (2)/(1) 7,6

Immigration Rate (2)/(1) 96,4

Emigration Rate (3)/(1) 1,3

Emigration Rate (3)/(1) 7,5

Net Migration Rate (4)/(1) 6,3

Net Migration Rate (4)/(1) 89,0

Region

Internal

External

Other

causes

Total

Piemonte 1,0 6,6 -1,4 6,2

Valle d'Aosta 1,7 5,3 -1,2 5,8

Lombardia 1,5 6,6 -1,5 6,6

Trentino-Alto Adige 2,3 5,4 -0,9 6,8

Bolzano-Bozen 1,9 4,8 -0,7 6,0

Trento 2,7 6,0 -1,1 7,6

Veneto 0,4 6,7 -1,9 5,2

Friuli-Venezia Giulia 1,3 5,2 -1,5 5,0

Liguria 1,8 5,3 -1,8 5,3

Emilia-Romagna 2,0 7,6 -1,9 7,7

Toscana 1,4 7,1 -1,7 6,8

Umbria 0,6 7,9 -1,3 7,2

Marche 0,4 6,6 -1,8 5,2

Lazio 1,6 7,3 -1,0 7,9

Crude Net Migration Rate by Region - 2011 (per 1.000 resident). Centre-North Regions

Crude Net Migration Rate by Region - 2011 (per 1.000 resident). South Regions

Region Internal External Other Totalcause

_____________________________________________

Abruzzo 0,9 5,4 - 1,0 5,3Molise 0,8 3,1 - 0,3 3,6Campania - 3,7 2,5 - 0,3 - 1,5Puglia - 2,1 1,9 - 0,4 - 0,6Basilicata - 2,7 2,2 - 0,1 - 0,6Calabria - 3,5 3,4 - 0,3 - 0,4Sicilia - 1,7 2,3 - 0,6 0,0Sardegna - 0,2 1,9 0,0 1,7

ITALIA 0.1* 5,3 - 1,1 4,3

Nord 1,3 6,6 - 1,6 6,3Nord-ovest 1,4 6,5 - 1,5 6,4Nord-est 1,3 6,8 - 1,8 6,3

Centro 1,3 7,2 - 1,3 7,2

Mezzogiorno- 2,2 2,5 - 0,4 - 0,1Sud - 2,6 2,7 - 0,4 - 0,3Isole - 1,4 2,2 - 0,4 0,4

Example

Calculate a immigration pluri-annual rate (IMR), considering:

nP1.1.2010=56,000,000 nP1.1.2008=55,000,000

IM2008-2009 = 900,000

Example: solution

nP1.1.2010=56,000,000 nP1.1.2008=55,000,000

IM2008-2009 = 900,000

Average Population (2008-2009) = AP2008-2009

AP2008-2009 = (56,000,000+55,000,000)/2 * 2 = 111,000,000

Finally:

IMR2008-2009 = 900,000 / 111,000,000 = 8,11 per thousands

Emigration and immigration rate: a paradox

The meaning of the out and in-migration rate unfortunately is not the same. While OMR is clearly a measure of propensity to go out of a population, IMR has not the same interpretation, because the propensity to enter to a specific place i moving from j different places depends of the propensity of these j different places to generate flows towards i. Clearly OMR is a measure of propensity (in other words it is a proxy of a probability), IMR is a measure of impact.

SPECIFIC RATES

• IMRi,x = IMi,x / Pi,x per 1,000 that is in-migration age-specific rate

• OMRi,x = OMi,x / Pi,x per 1,000 out-migration age-specific rate

• NMRi,x = (IMi,x - OMi,x) / Pi,x per 1,000 net-migration age-specific rate

with Pi,x average population at age x, that is the yearly population in age x on average

Specific Rate: an Example. Outflows (abs. value and rate). Male population, Italy 1991

age x Px,t Px,t+1 Average Outflows Outflow Specific Rate

      PopulationOAx,t (Abr.)

OIx,t (Interreg. OARx,t OIRx,t

0 292425 279983 286204 237 1072

1 286125 281773 283949 522 2839

2 287855 283370 285612,5 471 2643

3 280235 285289 282762 420 2406

4 281488 278884 280186 407 2034

5 291416 280661 286038,5 429 1779

6 295628 290391 293009,5 409 1855

7 303494 294793 299143,5 423 1542

8 312392 302720 307556 393 1490

9 319078 311715 315396,5 436 1465

10 324159 319253 321706 371 1303

11 336157 324123 330140 467 1689

12 358577 336069 347323 393 1254

13 372766 358533 365649,5 393 1219

14 393400 372696 383048 378 1323

15 416737 393242 404989,5 378 1340

16 437236 416509 426872,5 438 1442

Specific Rate: an Example. Outflows (abs. value and rate). Male population, Italy 1991

age x Px,t Px,t+1 Average OutflowsOutflow Specific

Rate

      PopulationOAx,t (Abr.)

OIx,t (Interreg. OEAx,t OEIx,t

0 292425 279983 286204 237 1072 0,8 3,7

1 286125 281773 283949 522 2839 1,8 10,0

2 287855 283370 285612,5 471 2643 1,6 9,3

3 280235 285289 282762 420 2406 1,5 8,5

4 281488 278884 280186 407 2034 1,5 7,3

5 291416 280661 286038,5 429 1779 1,5 6,2

6 295628 290391 293009,5 409 1855 1,4 6,3

7 303494 294793 299143,5 423 1542 1,4 5,2

8 312392 302720 307556 393 1490 1,3 4,8

9 319078 311715 315396,5 436 1465 1,4 4,6

10 324159 319253 321706 371 1303 1,2 4,1

11 336157 324123 330140 467 1689 1,4 5,1

12 358577 336069 347323 393 1254 1,1 3,6

13 372766 358533 365649,5 393 1219 1,1 3,3

14 393400 372696 383048 378 1323 1,0 3,5

15 416737 393242 404989,5 378 1340 0,9 3,3

16 437236 416509 426872,5 438 1442 1,0 3,4

Male outflows rate (interregional and external) by age. Italy, 2010.

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80

age

rate

OEFx,tOEIx,t

Male outflows rate (interregional and external) by age. Italy, 2010.

0,0

0,5

1,0

1,5

2,0

2,5

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

OEFx,t

OEIx,t

The age-model of OEF and OEI is quite the same

Total Mobility Rate: an exampleage x Px,t Px,t+1 Aver. Outflows

Outflow Specific Rate

      Pop. CFx,t CIx,t OEFx,t OEIx,t

0 292425 279983 286204 237 1072 0,8 3,7

1 286125 281773 283949 522 2839 1,8 10,0

2 287855 283370 285612,5 471 2643 1,6 9,3

3 280235 285289 282762 420 2406 1,5 8,5

4 281488 278884 280186 407 2034 1,5 7,3

… … … … … … … …

… … … … … … … …

79 124564 137066 130815 45 340 0,3 2,6

80 + 635116 671190 653153 275 1973 0,4 3,0

Total 27547371 27548440 27547906 37853 169400 1,4 6,1

TMT           103,5 446,1

TMT: Sum of age-specific mobility rates

Total Mobility Rate: meaning

Interregional Total Mobility Rate = iTMR

iTMR = 446,1 per 1000 resident

that’s 0,446 per capita, in other words the number of interregional movements attributed to a person during his “fictitious” life

B. Distance and direction of flow

origin and destination of the migration flows is

specified

Model and method → gravitational model, log-linear model