Measuring the impact of health insurance with a correction for selection bias--a case study of Ecuador.

This article develops and uses methodologies to evaluate the impact of publicly-financed health insurance programmes on the use of health care. Using univariate and bivariate probit estimation techniques, the study tests and corrects for endogeneity resulting from selection bias. Potential endogeneity arises from the choice to be insured, eligibility for insurance, and differences in individuals' health status. The setting for the study is the country of Ecuador. The General Health Insurance (GHI) programme, which primarily covers workers in the formal sector of the economy, is found to have a strong positive association with the use of curative health care after correcting for selection bias, but no significant effect on the use of preventive care. Individuals with severe illnesses who are eligible for GHI have a preference for private health care, and self-select out of the GHI programme. The Seguro Campesino Social (SSC) programme, directed at farming populations, has positive but insignificant associations with both curative and preventive care.