1. Counting the Dutch, The Future of the Virtual Census in the Netherlands Presentation at the seminar Counting the 7 Billion 24 February 2012 * Geert Bruinooge * g.bruinooge@cbs.nl

2. 1 Contents History of the Dutch Census Traditional and virtual Censuses Registers and surveys Strategy: order of data collection, system of basic registrations, basic registration stakeholders, challenges in surveys Virtual Census Introduction to virtual census, definition and driving forces of the SSD, combining sources: micro linkage, conditions facilitating use of administrative sources,advantages and disadvantages

3. 2 History of the Dutch Census (1) TRADITIONAL CENSUS Ministry of Home Affairs: 1829, 1839, 1849, 1859, 1869, 1879 and 1889 Statistics Netherlands: 1899, 1909, 1920, 1930, 1947, 1960 and 1971 Main problem: unwillingness (nonresponse) Additional problem: reduction of expenses  no more Traditional Censuses

4. 3 History of the Dutch Census (2) ALTERNATIVE: VIRTUAL CENSUS 1981 and 1991: Population Register and surveys Development 90’s: more registers → 2001 and 2011: Virtual Census: integrated set of registers and surveys Social Statistical Database (SSD) 2001: Gentlemen’s agreement (with Eurostat) 2011: European Census Act

5. Registers and surveys (1) Strategy: order of data collection 1.Secondary sources  where possible (total or partial replacement)  Statistics Netherlands has free access to all governmental data 2.Primary sources 1.Electronic/internet 2.Paper 3.Telephone 4.Face-to-face 4

6. 5 Registers and surveys (2) System of linked and unique basic registrations population (residents and non-residents) buildings and addresses enterprises (e.g. number of employees) real estates (boundaries, ownership, value,..) topography (maps: land, water, roads) motor cars (model, colour, ownership,..) taxable income (e.g. fiscal wage) labour (wage, employer,..) subsoil (sewerage, cables,..)

7. 6 Registers and surveys (3) Basic registrations stakeholders Features of basic registrations Based on legislations. Cabinet ministers are responsible for registrations. The Minister for the Interior is responsible for the system as a whole. Basic data are kept in only one register. Public sector organizations (ministries, tax authorities, local social welfare, …) are not allowed to collect and keep similar data. Stakeholders the cabinet minister (+ civil service) the keeper(s) of the registration the users (example: Statistics Netherlands)

8. Registers and surveys (4) Challenges in surveys Optimizing capacity (interviewers / agents) Contract management (CAPI / CATI) Home based interviewing Optimizing the use of different collection modes (mixed mode) with respect to Response rates Collection costs (capacity needed) Decreasing availability telephone numbers Special approach for difficult to reach groups because of low response rates 7

9. 8 Virtual Census (1) Introduction Why a Census? Statistical information for research and policy purposes What kind of information? Size of (sub)population(s), excluding illegal people (homeless are counted at last known address, special survey: catch-recatch method) Demographic and socio-economic characteristics, at national and regional level (frequency tables → small confidentiality problems Current situation Eurostat: coordinator of EU, accession and EFTA countries in the 2011 Census Round Census Table Programme, every 10 years

10. 9 Virtual Census (2) Definition and driving forces of the SSD Definition: set of integrated microdata files with coherent and detailed demographic and socio-economic data on persons, households, jobs and benefits After edit process: only coherent information Driving forces: Virtual Census of 2001 Better products: more coherence and flexibility

11. 10 Virtual Census (3) Combining sources: micro linkage Linkage key: Registers Citizen Service Number, unique Surveys Sex, date of birth, address (postal code and house number) Linkage key replaced by Record Identification Number of the person (because of confidentiality) Linkage strategy Optimizing number of matches Minimizing number of mismatches and missed matches

12. 11 Virtual Census (4) Conditions 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)

13. 12 Virtual Census (5) Advantages Relatively cheap (small cost per inhabitant: 1% of a traditional census) Quick (short production time) Less problems with non-response Annual updates are no longer necessary: Census data are continuously available!

14. 13 Virtual Census (6) Disadvantages 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 (e.g. occupation, level of education) How to keep knowledge and IT infrastructure up-to- date for a process that is running only every ten years? Attention for the Census (results) diminishes

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