Emerging methodologies for the census in the UNECE region

Paolo Valente

United Nations Economic Commission for Europe

Statistical Division

International Seminar on Population and Housing Censuses:

Beyond the 2010 Round

Seoul, Republic of Korea, 27-29 November 2012

United Nations Economic Commission for Europe

The UNECE Region:

Content:1. Shortcomings of traditional census approach

2. Alternative census methods:1. Fully register based census2. Combining data from registers + existing surveys3. Combining data from registers + ad-hoc surveys4. Combining data from registers + full enumeration5. Rolling census

3. Methods used in UNECE countries for 2010 round

4. Benefits and risks of alternative census methods

Content:1. Shortcomings of traditional census approach

2. Alternative census methods:1. Fully register based census2. Combining data from registers + existing surveys3. Combining data from registers + ad-hoc surveys4. Combining data from registers + full enumeration5. Rolling census

3. Methods used in UNECE countries for 2010 round

4. Benefits and risks of alternative census methods

«Combined census»

1. Traditional census

Direct count of all individuals and collection of their characteristics through the completion of census forms

1. Traditional census - ShortcomingsCensus management:

• Huge operation (largest peace time operation)• Very high cost (field staff, questionnaires, data processing, etc.)• Cost distribution over time (peak around field operations)• Recruitment of field staff (short-term employment of skilled staff)Fieldwork:• Cooperation with national and local administrations• Difficulties in enumerating certain population groups• Increasing reluctance of the population to participate in censusOutputs:• Timeliness• Frequency• Limited information content

2. Alternative methods:1. Fully register based censuses

• Based on integration of data from various registers• Conclusion of long step-by-step process• Census is part of a system of register-based information

Main requirements:• Availability of population register

and dwelling register • Capacity to link persons and

dwellings, identifying households• Public and legislative support for

the use of population registers

Advantages:• No burden on respondents• Limited cost once high quality registers are established• Data usually available every year

Disadvantages:• Setting up and maintaining registers requires significant resources • Only characteristics covered in the registers are available• Quality of census depends on coverage and quality of registers• Data in registers usually collected for non-statistical purposes

Nordic countries (from 1970s)

2. Alternative methods:1. Fully register based censuses

• Data from existing sample surveys (i.e. LFS) used for variables not available in registers

• Data linked at individual level• No field data collection

2. Alternative methods:2. Combining register data + existing surveys

Advantages:• No burden on respondents• Limited cost once high quality registers are establishedConsistency between census results and survey results

Disadvantages:• Process to link information on individuals from different

surveys and registers is complex• Limited detail for information taken from sample surveys

Netherlands (2001)

2. Alternative methods:2. Combining register data + existing surveys

• Ad-hoc sample surveys conducted:– for variables not available in registers (low detail)– to evaluate coverage and accuracy of registers

2. Alternative methods:3. Combining register data + ad-hoc surveys

Advantages:• Accuracy of population register can be tested• Population counts can be adjusted • Limited burden on respondents (sample survey)• Limited costs (sample survey)

Disadvantages:• Method can be complex to implement• Limited detail for information taken from sample surveys

Israel (2008)

2. Alternative methods:3. Combining register data + ad-hoc surveys

• Full enumeration conducted:– for variables not available in registers (high detail)– to evaluate coverage and accuracy of registers

• Some register data can be pre-printed in questionnaires

2. Alternative methods:4. Combining register data + full enumeration

Advantages:• Data collection can be used to update and improve registers

(in view of future fully register-based census) Distinction between census enumeration (stat. operation) ad register update (admin. operation) should be clear

• More efficient than traditional census thanks to use of registersDisadvantages:• Very expensive (full field enumeration)• Burden on respondents (full field enumeration)

Belgium, Latvia, Slovenia, Spain, Switzerland (2000 round)

2. Alternative methods:4. Combining register data + full enumeration

Implemented in France since 2004•Concept: Cumulative continuous survey, covering the whole country over a period of time (5 years)

– Small communes (<10,000 pop.): divided in 5 groups, every year full count in one group of communes (cycle)

– Large communes (>10,000 pop.): every year sample survey in 8% of households

•General results at national, regional level updated annually•Detailed results based on data cumulated over 5 last years, referred to year Y-2, for every geographical level

2. Alternative methods:5. Rolling census

Census methods adopted in UNECE Regionin 2000 and 2010 round

Census methods in Europe - 2010 round

Cost savings

Cost savings expected by most countries (14 out of 16)•Very high savings expected when there is NO field data collection:

– 85% in Austria – 90% in Iceland, Norway– 99% in Netherlands (actual savings)

•Lower savings expected with SAMPLE field data collection:– 40% in Poland (actual savings)– 50% in Turkey– 75% in Spain

•No savings expected with full field enumeration (Czech Republic, Italy)!!! Costs for setting up and maintaining registers are generally NOT included Net savings (taking into account costs for registers) are probably much

lower

6. Benefits and risks of alternative census methodsFirst results from 2010 census round in UNECE

Time savings

Time savings expected by 50% of countries (8 out of 16)•Most countries with NO field data collection expect NO time savings

– possibly due to schedule of updating of register data•Most countries with field data collection expect some time savings

– about 50% in Turkey (estimate)– Israel confirmed time savings (no figures available)

•Some countries with field data collection reported risk of time increase (Poland, Germany)

6. Benefits and risks of alternative census methodsFirst results from 2010 census round in UNECE

Other benefits expected:•Improved data quality (11 countries)•Improved coverage (9 countries) •Use of standardized census concepts and definitions (7 countries)•No (or limited) burden on respondents (6 countries)•Decreased non-response rate (5 countries)

Risks of alternative census methods:•Use of data source definitions instead of census definitions (7 countries)•Reduced topics (6 countries, all with no field data collection)•Decreased non-response rate (5 countries)•Limited output available (3 countries, all with no field data collection)

6. Benefits and risks of alternative census methodsFirst results from 2010 census round in UNECE

Census methodology in UNECE publications

http://www.unece.org/stats/census/

Content:- Table on 2010 round of censuses

in UNECE countries, including:- Census dates- Methodology / Use of internet- Questionnaires (PDF)- Technical papers and reports- Link to national census website

- Papers on census methodology

- Material for UNECE CensusTask Forces

- Discussion forum for census experts

Accessible from http://www.unece.org/stats/census.html or using Google:

Information on censuses at national level: UNECE Census Wiki