The Project Had Two Main Objectives
LUXEMBOURG
Introduction
Since 1855 Luxembourg has organised 28 population censuses, beginning with twice each decade, four times in the forties, then in 1960, 1966, 1970, 1981, 1991 and 2001. The enumeration was normally carried out in December (regularly until 1935 and four times consecutively after the Second World War), in the first months of the year in the three most recent cases.
In Luxembourg, as in other European countries, the population census is still the basic survey used to gather information concerning the demographic and socio-economic characteristics of the population and is the best source of exhaustive data down to the smallest geographical level.
The project had two main objectives:
establishing statistics on population and households (structure by sex, age, citizenship, education, living conditions, profession and economic activity, commuting to school or work), and
setting the usually resident population for the country and its administrative division (communes, electoral sectors, localities).
The second objective arises from a set of national laws obliging the National Statistical Institute (STATEC([1])) to determine the resident population through a census. This resident population is first used to attribute the size of the local administrative authorities; however population figures are also used to attribute taxes and concessions.
The last Population, Housing and Building Census was conducted on 15 February 2001. Questionnaires were dispatched and collected by enumerators. After checking and coding was carried out by the offices in the communes and STATEC, the collected information was entered using traditional data entry. Some innovative technologies were applied at the data dissemination phase.
Legislation
The main legal basis of the census is the electoral law. In addition, a regulation for the execution of the specific 2001 survey was issued on 18 January 2001. The inhabitants’ participation is compulsory to the relevance and success of the project. The same regulation allows for the setting-up and processing of a nominative database. Individual data collected during a census are confidential and may only be used for statistical purposes. All staff participating in the census are engaged with respect to statistical confidentiality.
Starting from 2001 the communes were able to use census data to update their population registers. At the same time the communes were asked to provide the census questionnaires with the basic data on sex, date of birth and citizenship (this agreement was not always respected).
Names and addresses of respondents were requested to technically facilitate enumeration (to avoid over- and under-counts and to modify the resident population of each locality taking into account that some people are enumerated away from their place of usual residence). The sheets presenting these data were separated from the questionnaires immediately prior to the data entry phase. Despite this method, the identification of respondents on the basis of the questionnaires was technically possible using the codes of the communes and the identifiers of enumeration area, building, dwelling and individual.
Registers
The Personal Identification Number (PIN) and several administrative registers are used in Luxembourg. The main and most reliable administrative source is the ‘Centre commun de la sécurité sociale’, where each person is registered as soon as he/she is employed in the country. This source is based on five different files and updated through the employer’s monthly report on wages. The population central register ‘Répertoire général des personnes phisiques’ (CPR) supplies information to the first register, however, notification of changes from the Social Security Authority, for instance when a person leaves the country may be late in arriving. Some data concerning the employer as the NACE code and the demographic statistics come from STATEC.
There are three main limitations to these sources:
-poor reliability of the CPR, with different methods applied by the communes in the registration of asylum seekers or problems arising from registration of employees at international organisations;
-the NACE code corresponding to the main activity of the employer instead of the activity carried out by each employee;
-the address of the employer always referring to the address of the head office.
Despite the above-mentioned problems, the social security files are the most important sources for employment and unemployment statistics. During planning for the 2001 Census the use of this system was avoided, because little of the information normally collected through a census could be taken from these sources – as they were unreliable, partial or had no information, respectively, on individuals, their profession or place of work.
The situation should however change in the future, first because the ‘Centre Informatique de l’Etat’ (CIE), which is responsible for the CPR will reorganise this register in the ‘Registre de l’Etat Civil et de la Population’ as the central element of an integrated registers system common to different institutions. In addition, Luxembourg will establish a new register of all localities and streets, under the authority of the ‘Administration du Cadastre’ and the support of the CIE, with a common database for the entire public sector([2]) useful for establishing a national register of buildings and dwellings over the long term.
Publicity and information
A public awareness campaign was undertaken on the census and information was broadcast on national TV and radio, newspapers, magazines and the STATEC Internet site. Brief information and instructions were provided with the questionnaires in four languages: French, German, English and Portuguese([3]).
Field operations
Field operations were carried out in 2826 enumeration areas using the following forms:
- the Bordereau de maison(Modèle I) and the control list (Modèle IV) assigned to the enumerators
- the form for households and dwellings (Modèle II) or the form for the institutional households (Modèle III), to be filled in directly by respondents
- summary sheets ’SE’ and ’QR’ (Modèles V et VI) assigned to the communes.
After enumeration and a first checking of the questionnaires, carried out by around 1847 temporary contracted workers over three weeks, based on the instructions received from STATEC the communes were responsible for:
-checking complete coverage of the enumeration;
-providing, when missing, data on sex, age and citizenship from their population registers;
-verifying the hierarchical numbering of the different documents regulating the identification of the form during the overall census process.
Later a (mostly manual) editing staff at STATEC carried out the following tasks:
-setting the resident population by commune and electoral section;
-coding of profession (ISO) and economic activity (NACE);
-correction of errors.
Unfortunately many questionnaires and control forms returned to STATEC displayed errors and missing data, causing a delay in providing the material to the external company responsible for data entry.
Another constraint to field work concerns inclusion of asylum seekers in the usually resident population. In fact, based on the advice of the Ministry of Justice, just before the enumeration it was decided to definitively consider, as usually resident in the country, only foreigners provided with a provisional permit of stay or an identity card. Later, as several communes did not respect these instructions, so as to treat all communes equally and to avoid supplementary and cumbersome correction, STATEC proposed considering all asylum seekers present in the country at census date as residents. This a posteriori solution is, however, in line with the yearly population evaluations where asylum seekers contribute to both the natural and migration balance.
Data processing
As stated above the data entry phase was outsourced to a private company. At this stage some remaining coding for NACE were automatically applied. The entire data entry phase was carried out by 2001, in about eight months.
Data dissemination
First provisional census results on resident population by communes, electoral sections and localities were published in February 2002 in the national regulation dated 28 January 2002. The technical and methodological aspects and especially the difficulties met in the definition of the resident population are largely represented. Although provisional results (based on control lists), having expected minor differences to the final, these data establish the number of ‘conseillers’ to attribute to each commune or electoral section.
Since May 2002 a set of thematic fiches of one or two pages in PDF format has been published on the STATEC Internet site presenting the analysis of disparities and similitude between the communes. These fiches, which are prepared in the framework of the Project GER([4]) with the support of the Luxembourg University Centre, will be grouped at the end in a census-based atlas of the communes ‘Portrait des communes’.
Final results displayed as a broad tabulation program were published on the Internet site in autumn 2002, first in an incomplete and preliminary version, later in the definitive and hard copy version.
Apart from standard tables, all census results will be further available in other forms upon request from users.
Costs
The overall cost of the Census will at end amount to around € 4 650 000.
Conclusion and future plans
Under the prevailing organisation of the Census the success of the survey strictly depends on the communes, on their accuracy in respect to instructions provided by STATEC. The latter does not have the means, or the individual records, to carry out checking or improvement of the collected data, this became obvious during the 2001 Census. The most recent experience gives support to STATEC in the use of administrative sources for the next census round. This will be after improving the national administrative register system and, before this, the central population register and the implementation of subsequent major changes to census legislation and data protection.
[1] Service Central de la Statistique et Etudes Economiques.
[2] There are currently several differences between the addresses used by the local authorities and those used by the post and some boundary lines of localities, which are changed according to the needs of the public services.
[3] Non-nationals represent about one-third the population living in Luxembourg. Among them, the Portuguese community is the most represented as a result of long-term immigration.
[4]Grande Etude du Recensement.