Dutch Virtual Census
Presentation at the International Seminar on
Population and Housing Censuses;
Beyond the 2010 Round
27-29 November, 2012
Egon Gerards, The Netherlands
Introducing Dutch Virtual Census
Short movie: Census Data http://youtu.be/SLpDkcyenf0
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Dutch Virtual Census – Egon Gerards
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Dutch Virtual Census
Presentation at the International Seminar on
Population and Housing Censuses;
Beyond the 2010 Round
27-29 November, 2012
Egon Gerards, The Netherlands
2
Overview
 The Dutch (Virtual) Census
 Census based on the Social Statistical Database
 Used methods
 Advantages/disadvantages of a virtual census
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History of the Dutch Census
 Traditional Census
 Ministry of Home Affairs: 1829, 1839,
1849, 1859, 1869, 1879, and 1889
 Statistics Netherlands: 1899, 1909, 1920,
1930, 1947, 1960, and 1971
 Experience of 1971: Unwillingness (nonresponse) and reduction expenses
 No more traditional censuses
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History of the Dutch Census
 Alternative: virtual census
 1981 and 1991: Population Register and surveys
development 90’s; More and more registers used
in the Census
 2001 and 2011: based on an integrated set of
registers and surveys: Social Statistical Database
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What is the Social Statistical Database?
Definition:
Comprehensive set of integrated micro-datafiles with
coherent and detailed demographic and socio-economic
data on persons, households, dwellings, jobs, and benefits
Two versions of the SSD:
 “fast” SSD (fast, regular statistics)
 micro integrated SSD (high-quality, longitudinally
consistent statistics)
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Facilitating use of administrative sources
 Legal base (Statistics Act)
 Public approval (‘Big Brother is watching you’)
 Cooperation among authorities (mainly
government organisations)
 Comprehensive and reliable register system
(administrative versus statistical quality)
 Unified identification system (preferably unique
ID-numbers)
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Census and SSD data sources
Population Register
Jobs file, containing all employees
Self-employed file, containing all self-employed
Fiscal administration
Social Security administrations
Pensions and life insurance benefits
Housing register
registers
 Labour Force Survey data around Census Day
survey
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Combining sources; from data to tables
 Micro linkage
 Micro integration
 Weighting technique
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Micro linkage
 Linkage key
 Registers: Citizen Service Number, unique
 Surveys: Sex, date of birth, address (postal code and
house number)
 Linkage key replaced by RIN-person (confidentiality)
 Linkage strategy
 Optimizing number of matches
 Minimizing number of mismatches and missed
matches
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Micro integration
Micro integration aims at improving data quality in combined
sources by searching and correcting for errors on unit level
 Collecting data from several sources; more comprehensive
and coherent information on aspects of a person’s life
 Compare sources: coverage and conflicting information
(reliability of sources)
 Integration rules: checks, adjustments, imputations
 Optimal use of information; quality improves
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Repeated weighting
 Creating register-survey tables
 Demand for overall numerical consistency
 one figure for one phenomenon idea
 all tables based on different sources (e.g. surveys)
should be mutually consistent
 Repeated Weighting (RW): technique to achieve
numerical consistency
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Dutch Virtual Census
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Collection of administrative registers
Surveys only additional and existing
No additional data collection
Linking the sources
Micro integration
Estimation/Weighting
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Advantages Virtual Census
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Relatively cheap (small cost per inhabitant)
Quick (short production time)
Less problems with non-response
It can be done permanently!
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Disadvantages Virtual Census
 Dependent on register holders (statistics is not their priority)
 Timeliness of registers
 Concepts and population of registers may differ from what is
needed (keep good relations with the register holders!)
 Publication of small subpopulations sometimes difficult or
even impossible because of limited information in already
existing surveys
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Dutch population 1829 - 2011
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Statistics Netherlands: microdata availability
 More information about the Dutch traditional Censuses
(including those of 1960 and 1971)
http://www.volkstellingen.nl/en/
 One percent samples for three years (1960, 1971 and 2001)
IPUMS (Integrated Public Use Microdata Series)
http://www.ipums.org/international/index.html
 Microdata sets for all three above years available for
research! DANS (Data Archiving and Networked Services)
http://www.dans.knaw.nl/en/
 Centre for Policy Related Statistics; research for
commissioned work and remote access to microdata for
research: www.cbs.nl/cvb
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The Netherlands
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300 km long, 200 km wide
Quarter of the land below sea level
16,7 million people
Densily populated: 500 persons / km2
Kingdom: Queen Beatrix
Thank you for your attention!
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More information Census 2001
 Tables 2001 http://www.cbs.nl/nlNL/menu/themas/dossiers/historischereeksen/publicaties/volkstelling-2001/2003-volkstellingexcel.htm
 Book and extra chapter 2001 http://www.cbs.nl/nlNL/menu/themas/dossiers/historischereeksen/publicaties/volkstelling-2001/2001-b57-pub.htm
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