Dutch Virtual Census

1. 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. Introducing Dutch Virtual Census Short movie: Census Data http://youtu.be/SLpDkcyenf0 test Dutch Virtual Census – Egon Gerards

3. 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

4. Overview • The Dutch (Virtual) Census • Census based on the Social Statistical Database • Used methods • Advantages/disadvantages of a virtual census test Dutch Virtual Census – Egon Gerards

5. 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 (non-response) and reduction expenses • No more traditional censuses test Dutch Virtual Census – Egon Gerards

6. 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 test Dutch Virtual Census – Egon Gerards

7. 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) test Dutch Virtual Census – Egon Gerards

8. 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) test Dutch Virtual Census – Egon Gerards

9. 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 • Labour Force Survey data around Census Day registers survey test Dutch Virtual Census – Egon Gerards

10. Combining sources; from data to tables • Micro linkage • Micro integration • Weighting technique test Dutch Virtual Census – Egon Gerards

11. 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 test Dutch Virtual Census – Egon Gerards

12. 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 test Dutch Virtual Census – Egon Gerards

13. 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 test Dutch Virtual Census – Egon Gerards

14. Collection of administrative registers Surveys only additional and existing No additional data collection Linking the sources Micro integration Estimation/Weighting Dutch Virtual Census test Dutch Virtual Census – Egon Gerards

15. Relatively cheap (small cost per inhabitant) Quick (short production time) Less problems with non-response It can be done permanently! Advantages Virtual Census test Dutch Virtual Census – Egon Gerards

16. 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 Disadvantages Virtual Census test Dutch Virtual Census – Egon Gerards

17. Dutch population 1829 - 2011 test Dutch Virtual Census – Egon Gerards

18. 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 Statistics Netherlands: microdata availability test Dutch Virtual Census – Egon Gerards

19. The Netherlands • 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! test Dutch Virtual Census – Egon Gerards

20. More information Census 2001 • Tables 2001 http://www.cbs.nl/nl-NL/menu/themas/dossiers/historische-reeksen/publicaties/volkstelling-2001/2003-volkstelling-excel.htm • Book and extra chapter 2001 http://www.cbs.nl/nl-NL/menu/themas/dossiers/historische-reeksen/publicaties/volkstelling-2001/2001-b57-pub.htm test Dutch Virtual Census – Egon Gerards