The projection method combines total population projections and participation rate projections for the different categories of gender and age reached at the end of the year.

The latter are based, for categories of age less than 54-year-old, on the econometric modelling of the rates, which isolates a development trend (accounted for by a logistic function of time), and superimposes certain inflexion factors as people development of learning.

Activity rates of seniors are evaluated by INSEE's "Destinie" behaviour model, which simulates life courses and projects the situation of retired people by taking into account the effect of pension reforms until 2014.

The modelling of participation rates seeks to isolate a long-term trend and thus does not take account of the short-term economic situation. However, the size of future fluctuations of the labour force may be estimated by means of activity variants using others demographics or statistical hypothesis.