Estimating health insurance impacts under unobserved heterogeneity: the case of Vietnam's health care fund for the poor
研究了越南贫困人口医疗基金对医疗服务使用和自付支出的影响，发现该基金未增加服务使用但显著降低了自付支出，对政策制定者评估保险覆盖效果有参考价值。
Vietnam's health care fund for the poor (HCFP) uses government revenues to finance health care for the poor, ethnic minorities living in selected mountainous provinces, and all households living in communes officially designated as highly disadvantaged. As of 2006, the program, which started in 2003, covered around 60% of those eligible. Those who were covered (about 20% of the population) were disproportionately poor, and around 80% of those covered were eligible. Estimates of the program's impact were obtained using a method that takes into account unobserved heterogeneity--including unobserved idiosyncratic returns--but requires minimal assumptions. The downside is that it provides an estimate only of the program's impact on those covered by it; it cannot therefore answer the question of how those currently uncovered will fare when they are eventually covered. The results suggest that HCFP has had no impact on use of services, but has substantially reduced out-of-pocket spending.