How to deal with two different sources: registers and survey?

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Geneva 30 sept 2013

Group of Experts on Population and Hosing Censuses: XV

Meeting

Jorge L. Vega Valle (INE-SPAIN)

jorgeluis.vega.valle@ine.es

How to deal with two different

sources: registers and survey?

How to deal with two different sources: registers and survey?

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Registers and surveys: Starting point

Registers:

Topic 1

Topic 2

... Topic “mr”

Record 1

Record 2

...

Record “nr”

Topic 1

Topic 2

... Topic “ms”

Record 1

Record 2

...

Record “ns”

Surveys:

Normal situation:

nr >>> ns

mr <<< ms

Spanish Census:

nr 47M

ns 4M

mr 10

ms 200

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Procedure for building the Weighted Census File-WCF (1)

Topic 1

Topic 2

... Topic “mr”

Record 1

Record 2

Record 3

Record 4

Record 5

...

Record “nr”

Registers used: +Population Register (most important) +Tax Agency +Social Security +Vital Statistics

Records included (nr = 47.711,000): +Information from Population Register +Births included in Vital Statistics

Information is crossed Likelihood of residence(count factor)

3 possible situations (after evaluating 15 different possibilites in registers used): >Enough evidence to count record (CF=1): 97.2% of the records >Enough evidence to delete record (CF=0): 0.6% of the records >Doubtful population (CF to be assigned): 2.2% of the records. Most of them foreigners

CF

1

p

1

0

1

1

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Procedure for building the Weighted Census File-WCF (2)

Procedure for assigning CF to 1,046,000 doubtful records: -These records were divided on 724 classes (each one of at least 1,000 doubtful records) -Depending on demographical variables

-Example of classes: +Spanish people between 0 and 4 years old (both included) living in Madrid region +German people between 70 and 74 years old (both included) living in Alicante region +...

-All the records that belong to the Same class Same CF

i

i

i

i

i

i

i

S

Dis

id

classWCFrecordssure

classWCFrecordsdoubtfulclasssamplerecordssure

classsamplerecordsdoubtful

CF

___

______

___

1,046,000 doubtful records were counted as 443,000 people (average CF of 0.424)

Census population figure = CFi = 46,815,916

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Census survey

Features of the Census survey:

-Big size: ns=4,108,564 (9% population) >Average sampling weight (SW) of 11 >All the people living in the same dwelling will have the same sampling weight

Topic 1

Topic 2

... Topic “ms”

Record 1

Record 2

...

Record “ns”

SW

SW1

SW2

SWns-Information from all the variables needed

>Economy topics

>Migration topics

>Place of work/study topics

>Relation between household members

>...

-Information from basic topics can be obtained from WCF or Census survey It should be the same (as many times as possible)

>Calibration between Counting Factors of the WCF (CFi) and Sampling Weights of the Census

Survey (Swi) in order to minimize differences

>Total calibration is not possible

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Calibration technique – CALMAR (1)

CALMAR: >Calibration method developed by Särndal and others >Used by several public statistical offices. Possible to download from www.insee.fr

>Information from the WCF play the role of being the “population frame” and the Census survey parameters (SW) should be adjusted in order to reflect the same information than the WCF (CF).

>Sampling Weights (SW) were calculated using CALMAR

Calibration is done in each one of 8,116 Spanish municipalities (and in some districts): >Mun. with 50 or less inhabitants: TOTAL POPULATION >Mun. between 51 and 200: SEX >Mun. between 201 and 2,000: AGE.L >Mun. between 2,001 and 10,000: AGE.M >Mun. between 10,001 and 50,000: AGE.M and COC.L >Mun. between 50,001 and 100,000: AGE.H and COC.L >Mun. with 100,001 or more inhabitants: AGE.H and COC.M

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Information that is calibrated: >Same answer WCF (using CF) and Survey (using SW)

But...information that is not calibrated, could give: >Different answers WCF and Survey Inconsistencies

Calibration technique – CALMAR (2)

Example of incosistencies: Almería (NUTS3 Spanish region with more than 250,000 people)

  WCF Census survey

Total population (Calibrated) 688,735.62 688,735.62

Foreign population (Calibrated) 137,214.23 137,214.23

Population with 29 years old (Not calibrated) 11,728.62 11,675.26

Population from France (Not calibrated) 1,627.08 1,724.34

=

=

Very important to explain users the reason of these differences.Users will have to live with this situation...

CF SW

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Contact information

Jorge L. Vega VallePopulation Statistics Department

http://www.ine.es

jorgeluis.vega.valle@ine.es