Decomposing Body Mass Index Gaps Between Mediterranean Countries: A Counterfactual Quantile Regression Analysis

Wide cross-country variation in obesity rates have been reported within European Union member states. However, health production determinants for these differences have been largely overlooked in the health economics literature. In this paper we propose a methodology for conducting standardized cross-country comparisons in BMI. The method we adopt is based on the estimation of the marginal density function of BMI in a given country implied by different counterfactual distributions of all the covariates included within a quantile regression framework. We apply our method to the analysis of the variation in BMI distribution in Spain with respect to Italy in the year 2003. Our findings suggest that Spain-to-Italy BMI gaps are largely explained by cross-country variation in the returns to each health input. Therefore, there appear to be differences in the country-specific behavioural responses to the caloric (im)balance.