INSEE revises the values of its statistics to reflect reality as accurately as possible and to ensure their relevance and reliability. It uses well-established, standardised and planned procedures according to international standards. It announces revisions simultaneously with their release or in advance according to a protocol adapted to the source of the revisions, their magnitude and the sensitivity of the published statistics. All the explanations necessary for understanding these revisions accompany the release of the statistical sources concerned on the insee.fr website.

Quarterly estimates of localised unemployment rates may be revised from one quarter to the next for various reasons.

Incorporation of new source data

The inclusion of new source data may lead to revisions in the employed population or the number of unemployed. This concerns in particular :

• data on frontier workers from the OFS in the second and fourth quarters ;

• data on frontier workers from the population census in the first quarters;

• the unemployed in each quarter;

• data from the Employment survey: survey of non-respondents and new weights

Calibration to new annual employment levels

The incorporation of a new provisional or definitive annual employment point (calculated from Estel data) leads to revisions to the localised unemployment rates. The revisions affect non-agricultural market employment, as well as self-employment and employment in the agricultural and non-market sectors. They take place twice a year, in March and in the autumn.

Updating of seasonal coefficients

For the quarterly number of unemployed, the seasonal coefficients are recalculated every quarter. The series may then be slightly revised. The revision of the seasonality models, which takes place once a year, may lead to somewhat larger revisions.

For quarterly employment data, the revision of seasonal coefficients occurs only once a year.

At the national level, the seasonal coefficients on the number of unemployed and on employment are recalculated every quarter. Because they are based on the national quarterly levels, the localized series may be affected.