Changes in the distribution of the Body Mass Index in France, 1981-2003: a decomposition analysis.

Summary Recentered Influence Function (RIF) regressions are used to decompose the changes in the distribution of Body Mass Index (BMI) in France between 1981 and 2003 into a composition effect produced by shifts in the sociodemographic composition of the population, and a structure effect from changes in the marginal effect of various factors on BMI. The impact of educational expansion, population ageing, the rise in divorce and immigration are separately identifed. The empirical results clearly illustrate the non-market benefits from education policies. In the absence of educational expansion, the median BMI would have increased by 1:28 points instead of 0:93 points for women, and 0:89 points instead of 0:74 points for men. The structure effects also reveal a 11% increase in education-related inequalities for women and a 8% rise for men. While ageing explains part of the rise in BMI, the age-BMI profile has flattened, showing that younger cohorts are heavier. There is also suggestive evidence that immigration has contributed to the rise in BMI, while the increasing proportion of singles is associated to a negative composition effect.