Decomposing the causes of inequalities in health care use: a micro-simulations approach.

We propose an innovative method for the decomposition of factors associated with inequalities in the use of health care. We analyze individual data and make use of micro-simulations to evaluate the effect of heterogeneity of individual behaviors on inequality in access to care. Our study employs methods that, unlike earlier work, permits evaluation of heterogeneity of individual behaviors. We provide an application of this method by decomposing inequality of health care use in France in 1998. We show that half of the inequity in access to care is due to the heterogeneity of behaviors relative to the rank of individuals in the income distribution. This approach reconciles Oaxaca-like decompositions of inequality, focused on outcome gaps, with analyses involving decompositions of inequality by factors, focused on inequity indices.