In 2003, one in three men aged between 40-59 years had a social status identical to that of his father at the same age. This figure hides very varied situations according to the social group: 9 out of 10 farmers have the same social status as their father, compared to 2 out of 10 managers. Over the last 25 years, the evolution of the social structure has favoured mobility. In 2003, 40% of social mobility was thus due to structural changes in the economy. The net mobility of the labour market transformations, however, fell between 1977 and 2003. The unequal access to a higher social status increased.