Continuous

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

Data is collected by computer-assisted data collection (CAPI). The interview is done face to face for the first and last waves and by phone for the intermediate waves.
If a person cannot respond (or does not want to), another person household can answer in their  place (proxy).

An annual specific survey is conducted in Mayotte.

The data collection is conducted continuously, every week of the year. The interview is usually conducted in the 2 weeks and 2 days 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 sample is currently being renewed. As of Q3 2019, each new cluster (1st wave : 1/6th of the sample) belongs to the new sample. This will ensure the gradual renewal of the sample. In the end, the sample from Metropolitan France will be completely renewed in Q4 2020. The sampling frame is the housing-tax register for the old sample and the demographic file of dwellings and individuals (<< Fideli >>) for the new sample.  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 complementary module is asked to the outgoing clusters.

Each quarter, until Q3 2019, 92,000 dwellings are surveyed, 73,000 of which are principal residences and are in the target population. The size will gradually decrease with the renewal of the sample. In the end, in Q4 2020, the sample size will be about 15% smaller.

For Metropolitan France, a unique calibration is performed both to correct biases induced by non-response and to get consistency with external margins. The margins are individual characteristics (sex, age, NUTS2,...) and dwelling characteristics (number of dwellings, type of housing, income of the households,...). 
For DOM, weights are first adjusted by using an estimation of response probabilities, and are next calibrated on external margins (number of dwellings, type of housing, diploma, place of birth...).