Inégalités de richesse et démographie différentielle. L'effet de la taille des fratries sur la concentration de la richesse à Paris et en France, 1860-1914.

During late XIXth century, and XXth century until the "baby-boom", French demography was very specific in comparison with European standards. Data from successions show indeed that average family was small, and that a large share of individuals died with no child inheritor at all. This seems however to have been different in very rich families. By the richest Parisian wealth holders - who possessed more than 50\% of total wealth before World War I in Paris - the number of children by deceased was twice as high as in the "middle-class", because small families and indirect (childless) inheritance were less frequent. To understand the effect of differential demography on capital redistribution at each generation, I designed a simulation model counting the total wealth inherited by inheritors of different social worlds. Until World War II, Malthusian France was a place where inheritors received a total amount of wealth that made them richer than each of their parents. This was especially true in a city like Paris, from the Second Empire to at least World War II. Middle-class individuals of small families experienced mechanical upward mobility because of direct and indirect inheritance, whereas a big proportion of top family inheritors experienced the opposite. Beyond the question of transmission, it is necessary to understand if family structures has long term effects on individuals, or if inheritors can compensate capital dilution by other means (e.g. work, saving). Observation from a new data set following 800 very rich Parisian families on two generations tends to prove that individuals of larger sibships never caught-up with the others. Moreover, for a given amount of total inherited wealth, it seems that larger sibships had a negative effect on the inheritor's wealth at death. This could be explained by coordination problems between brothers and sisters to manage parental estates.