The French Rolling Census

Regional Workshop on the 2010 World Programme on Population and Housing Censuses: International standards, contemporary technologies for census mapping and data processing

Minsk, Belarus, 8-12 December 2008

The French Rolling Census



GENERAL PRESENTATION OF THE CENSUS

Why renovate The method of the new census The conditions for renewal More indepth consultation The cost of the census Enhanced partnership with the communes The different steps in the census survey Dissemination



WHY RENOVATE? To respond to more recent needs of statistics To smoothen the costs and the expenses (and

therefore, better staff and control the operations)

Renovation has enabled the consolidation of the legal edifice and the clarification of the partnership with the communes



THE METHOD OF THE NEW CENSUS Two major principles

Data collection in rotation Resorting to sample surveys for large

communes (more than 10000 inhabitants) The sampling base: the located buildings

register (répertoire d’immeubles localisés - RIL)

Special case of persons not living in ordinary dwellings



SAMPLING STRATEGY Communes of less than 10 000 inhab. :

~ 30 M inhab. x 1/5 x 100 % = 6 M Communes of 10 000 inhab. Or more :

~ 30 M inhab. x 1/5 x 40 % = 2.4 M Total : 8.4 M soit ~ 60 M / 7



THE SAMPLING FRAME IN LARGE COMMUNES: THE RIL A register of located addresses, in geographical co-ordinates:

The addresses of residential buildings, with variables such as the number of dwellings

The addresses of the local units of the enterprise register

The georeference in X and Y of each address Scope: The 892 communes of more than 10 000

inhabitants :





HOW IS THE RIL MAINTAINED A continuous update is necessary:

identification must be made of the new addresses, changed addresses and addresses destroyed Comparison with files: Building permit, files

of addresses of La Poste, Tax files… Exchange of data with the local authorities,

and operations of expertise of the communes Returns of census data collected, out of 8% of

addresses annually In the field verification…





ONE YEAR OF COLLECTION FOR EACH COMMUNE

In 2009, we start again …

(example of Bas-Rhin)

"communes 2008" (less than 10 000 inhabitants)




"communes 2004« (less than de 10 000 inhabitants)

Communes concerned each year(10 000 inhabitants or more)

Haguenau

Strasbourg

Sélestat

Saverne





A GROUP OF BUILDINGS CONCERNED EACH YEAR

And in 2009,we start again …



THE SAMPLING PLAN 2 strata = «addresses of large size» and « other

addresses » «addresses of large size» : 5 groups for rotation,

one group surveyed exhaustively each year « other addresses » : 5 groups for rotation, one

group sample surveyed each year Five groups balanced in terms of number of

dwellings, number of dwellings in collective housing, five age-groups and gender



SAMPLE OF THE YEAR We remove from the groups the addresses

disappeared We distribute the new addresses by seeking to

strike a balance in the number of dwellings and the breakdown between collective / individual housing

The group of the year of large size addresses is surveyed exhaustively

The group of other addresses of the year is sample surveyed to reach 40% of the group Criteria : number of dwellings and breakdown between

collective/individual, weight of the IRIS in number of dwellings



THE ESTIMATION PRINCIPLES Each year, for each commune, the estimation of

the population at 1st January N-2

Mobile averages for the large communes

Interpolation and extrapolation for the small ones

An update limited to two years maximum



THE ESTIMATION MECHANISM Communes with less than 10000 inhab. :

Exhaustive census every 5 years Population updated by :

Interpolation-extrapolation Taking into account administrative sources

(Housing Tax files)

Communes with 10 000 inhab. or more : Sample surveyed at 8 % every year, i.e. 40 % over

5 years Mobile sum over 5 years Fitted over the number of dwellings of the median

year (RIL)



THE CONDITIONS FOR RENEWAL The opportunities that we have benefitted from:

Statistical techniques enabling the construction of balanced samples

The possibility of building a Located Buildings Register - RIL (Répertoire d’Immeubles Localisés) to serve as a sampling base

Administrative sources of better quality, to contribute to the surveys and update the RIL

A « high confidence level » … indicate the conditions for success



AN INDEPTH CONSULTATION How to renovate : the consultation and the legal

edifice Laws and decrees National and local consultation (National

Council on Statistical Information –CNIS and the regional directorates)

Commission of the CNIS to prepare the decree (organisation of the census and the principles of the calculation of the legal population)

Scientific committee (validation of the method)



THE COST OF THE CENSUS No additional expenditure The total external cost : approx. 30 M€ per

annum (external costs), to compared with 200 M€ for a general census

The cost is therefore smoothened and is more « profitable » because one provides data each year

The non-financial charges are also smoothened

On the whole a better cost-advantage ratio



A STRENGTHENED PARTNERSHIP WITH THE COMMUNES

They co-manage the training of enumerators

They follow the data collection procedure

They control the quality and exhaustiveness of the data collection

They watch over the respect of confidentiality of the data they co-ordinate their communication actions

The Communes prepare and perform

the census survey

The Communes prepare and perform

the census survey

The Insee organises and checks data

collection



The partnership between Insee and the communes is better defined

The contributions : based on the closeness of the communes with the inhabitants which has proven its worth in the previous censuses

The professionalisation of the communal stakeholders : an essential factor of improvement

A STRENGTHENED PARTNERSHIP WITH THE COMMUNES



THE PROCEEDINGS OF THE CENSUS SURVEY The same modus operandi as in 1999 for the

habitants : deposit-withdrawal of the questionnaires by the enumerator

A « non surveyed dwelling form » (called FLNE in french) in case of impossibility of contacting people or refusal



The questionnairesThe dwelling data sheet

The individual bulletin



IN LINE WITH QUALITY CRITERIA The essential characteristics of the census

(defined by the UN) : Individual listing Universality Simultaneity Capacity to supply data on small fields Regularity



INDIVIDUAL LISTING Data for each individual and each household

interviewed in the census

Organised in a « detail » file allowing for all kinds of comparisons

Sampling rate sufficient for all kinds of cross-tabulations



UNIVERSALITY Guaranteed in the small communes because each

dwelling is interviewed in the census Guaranteed in the large communes by the RIL which

covers all the addresses of dwellings and by the sampling rate (40%)

The institutions (communities) are exhaustively interviewed

Homeless persons and those living in mobile homes, exhaustively interviewed for the census, are subject to an adapted data collection protocol

Data collection is controlled through a comparison with the Housing Tax files and with the RIL



SIMULTANEITY The annual survey takes place for all the

communes concerned at the same date

The data collected at different years are brought down to the same date, thanks to administrative files, or through a mobile average



CAPACITY TO SUPPLY DATA ON SMALL FIELDS Stems from both universality and individual

listing

Garanteed by the sampling rate (100% in the small communes and 40% in the large ones)

The census will supply data on all the communes and on the « IRIS », districts of about 2000 inhabitants



REGULARITY Criteria met by construction because

one supplies annual data



CENSUS STEPS

Located

buildings register

(R.I.L)

Data Collection Sampling

Data Collection preparation

Households Communities

Communities register Receipt, Checking

Restitution to the mayors Dissemination

Preparation of data entry

Validation

of the data

Estimation of datas :

population and detailed datas

Imputation of missing datas

Coding

Automatic then manual

recovery

Data entry

(external service provider)

Addition of the weights and updating of geography



Sep.Juin Jui. Août Oct. Nov. Déc. Mar JuinAvril MaiJan Fév. Sep.Jui. Août Nov. Déc. Jan

Year N-1 Year N

THE SCHEDULE OF A CAMPAIGN

Sampling

RIL Expertise

Setting-up of organisation

Preparation

Training

Communication

Collection

Reception

Controls

Data processing

Oct.

Dissemination

Documents

The French Rolling Census