In many developed countries, the share of wage employment out of the total agricultural labour force has been increasing for the last ten years. Using data from French agricultural censuses, we present an analysis of the factors that influence households' decisions about whether to work on the family farm or to work outside, and about the use of wage labour. Studying how the effects of these factors have varied between 1988 and 2000 enables us to highlight the different mechanisms that have led to an increase in permanent wage employment during that period. In particular, we show that family labour and permanent wage labour have become nearly equivalent in 2000, whereas that was not the case in 1988.