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…

In 2009, we start again … ONE YEAR OF COLLECTION FOR EACH COMMUNE (example of Bas-Rhin) Communes concerned each year (10 000 inhabitants or more) "communes 2004«  (less than de 10 000 inhabitants) "communes 2007" (less than 10 000 inhabitants) "communes 2008" (less than 10 000 inhabitants) "communes 2006" (less than 10 000 inhabitants) "communes 2005" (less than 10 000 inhabitants) Haguenau Strasbourg Sélestat Saverne In 2009, we start again …

A GROUP OF BUILDINGS CONCERNED EACH YEAR And in 2009, we start again … 3

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 The Communes prepare and perform the census survey The Insee organises and checks data collection Together : 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

A STRENGTHENED PARTNERSHIP WITH THE COMMUNES 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

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 questionnaires The 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

THE SCHEDULE OF A CAMPAIGN Sep. Juin Jui. Août Oct. Nov. Déc. Mar Avril Mai Jan Fév. Year N-1 Year N Oct. RIL Expertise Sampling Setting-up of organisation Preparation Training Communication Collection Reception Controls Data processing Dissemination