Type of source : administrative data ("déclaration sociale nominative")

Monthly

Data collection media: Enterprises transmit information from their payroll software to a single point of deposit just once a month.

This information is checked and then redistributed to the various recipient organisations.

Planned changes in data collection methodology : None.

Data for month M is collected before the 15th of month M+1.

By Internet

Local unit (of an enterprise)

No sampling plan.

Not applicable (administrative data)

Data are validated before they are transmitted to Eurostat.

Estimates for non-response : none, except for the last few months due to a few late declarations (< 1% of the total declarants)

Estimates for grossing-up to population levels : none

Type of index : Annual chain-linked Laspeyres indices with 2021 as reference year

Method of weighting and chaining : The weightings of the branches are based on annual raw value added at basic prices. The indices have a mean of 100 in 2021.

Planned changes in production methods: None.

Indices are seasonally and working-day adjusted.

The raw indices are seasonnaly and working-day adjusted (SA-WDA) using the X13 ARIMA program available in JDemetra +. The WD adjustment (trading days, leap year) and the seasonal adjustment decomposition are calculated at the 4-digit level of the NACE Rev. 2. The upper levels are obtained by aggregating the series (indirect method), in the same way as the agregation of raw data.

The Reg ARIMA calendar adjustment is used by constructing working day regressors based on the French national calendar (which takes into account working days specific to France).

Outliers (additive outliers, temporary changes, level shifts, seasonal outliers) are fixed in the past and are detected automatically on the past 12 months onwards. The critical value for outlier detection, the filter length and the model/filter selection depend on the series and may have to be changed manually to improve the quality of the seasonal correction. This was the case to neutralize some particular points associated with the 2020-2021 health crisis (lockdowns for example), which would have induced an unjustified distortion of the seasonal coefficients over the past.

Either additive or multiplicative decomposition can be used. The seasonal adjustment models are reexamined every year (favouring stability) and the parameters are re-estimated every month.

Each month the SA-WDA data are revised from 2012. For the seasonal adjustment of indices in the recent past, the models are now estimated over a reduced sub-period (from 2012 onwards), in accordance with Eurostat guidelines, and in order to reinforce the robustness of the seasonal adjustment. The data before 2012 are fixed in evolution, in accordance with Eurostat's guidelines (avoid revisions over a too long period).