Annual

Municipalities with fewer than 10,000 inhabitants carry out a census survey of the entire population, in one out of five municipalities each year.

Municipalities of 10,000 inhabitants or more carry out an annual sample survey of a sample of addresses representing 8% of their dwellings.

Collection begins on the third Thursday in January, except in Reunion and Mayotte, where it begins two weeks later, and in Saint Pierre and Miquelon, where it takes place in March-April.

It lasts just over four weeks in municipalities with fewer than 10,000 inhabitants and in communities, and just over five weeks in municipalities with 10,000 inhabitants or more.

For each annual survey, the large municipalities follow a two-phase sampling plan in the Address Survey Base (ASB) created from the annual data of the Localised buildings register (RIL).

First phase of sampling:

In metropolitan France, the residential buildings (or addressed entities) were divided into five rotation groups by balanced random draw. The drawing of the sample of buildings from a given ACS mobilises only one of the five rotation groups, by rotation. The constitution of the buildings rotation groups constitutes the first phase of the draw.

In the French overseas departments, each large municipality was partitioned into several sets of contiguous buildings known as << îlots >>. In each municipality, the << îlots >> were divided into five rotation groups. The constitution of the rotation groups constitutes in this context the first phase of the draw.

Second draw phase:

Addressed entities belonging to the strata of large buildings, new buildings and tourist establishments are exhaustively enumerated. The buildings belonging to the stratum of known small addresses are selected in such a way as to obtain 40% of the dwellings surveyed in the annual rotation group.

In the 2022 ACS, 5.5 million dwellings and 10,0 million people were surveyed.

A variable distinguishes the mode of response (paper or Internet) chosen by the respondents.

The questionnaires (individual bulletin, individual bulletin for communities, housing sheets for metropolitan France and the overseas departments) as well as the explanatory notes are available on the site "the census and me" (site updated at each ACS).

Data collection involves many actors. Its quality depends on precise and rigorous procedures, but above all on the support of respondents (which conditions the sincerity of their answers) and the commitment of those who collect the information, i.e. the enumerators. Rigorous preparation (fieldwork, training of those involved) and controls ensure quality. During the collection, checks are carried out both by the municipalities and by INSEE.

The first phase of the statistical analysis, known as the main phase, deals with all the questionnaires collected. It deals with all the information that can be easily coded after the questionnaires have been entered.

The second phase of the exploitation, known as complementary, is intended to produce the variables whose elaboration is more complex and which describe:

• The family structure of the households: precise determination of the reference person of the household, identification, if necessary, of families within the household and composition of these families;
• The sectors of activity in which the jobs are carried out;
• The occupation and socio-professional category of the persons.
  Since the 2014 survey, the supplementary analysis has covered one-fifth of households in municipalities with fewer than 10,000 inhabitants, and all the forms collected from households (i.e. around 40%) in municipalities with
  10,000 inhabitants or more. For all communes, the complementary analysis also covers one individual in 5 communities.

The calibration margins of the 2022 ACS are based on the 2019 population census and the demographic file of dwellings and individuals for the year 2021.