Continuous

The survey is conducted continuously, every week of the year.

Data collection is carried out under computer-assisted collection (CAPI), face-to-face for the first interview of the household, and by telephone or internet for the re-interviews.

An annual specific survey is conducted in Mayotte.

The data collection is conducted continuously, every week of the year. The interview is conducted in the 3 weeks following the reference week.

Each dwelling is surveyed six consecutive quarters.

Household

• The sampling unit is dwelling. The sample is rotational: each cluster is surveyed 6 consecutive quarters, then replaced by a new cluster of the same sector.
• In Metropolitan France, the sampling frame is the demographic file of dwellings and individuals (<< Fideli >>). The sample selection is stratified by region. For each region, the sample is balanced, proportionnaly of the number of main residences, on some variables from the sampling frame.
• For DOM, the sampling is stratified (geographic strata) and systematic (with equal inclusion probabilities, within geographic strata).
• The sample is uniformely distributed among the 13 weeks of the quarter. Each cluster is affected to a reference week.
• The average sampling rate is 1/400.
• The complementary module is asked to the ingoing clusters.

In 2021, each quarter, 80 000 dwellings are surveyed.

• For metropolitan France, a two-steps weighting method is applied: calibration and non-response model on variables from the sampling frame in the first step, calibration on external data (population by age, sex and region; number of dwellings) in the second step.
• For DOM, a two-steps weighting method is also applied: non-response model on variables from the sampling frame in the first step, calibration on external data (population by age, sex and region; number of dwellings) in the second step.