The impact of Medicaid on medical utilization in a vulnerable population: Evidence from COFA migrants
研究了2015年夏威夷州停止对COFA移民提供医疗补助后，该群体的住院和急诊次数分别下降31%和19%，而私人保险的增加未能完全弥补这一缺口，且无保险急诊次数上升。
In March 2015, the State of Hawaii stopped covering the majority of migrants from countries belonging to the Compact of Free Association (COFA) in its Medicaid program. COFA migrants were required to obtain private insurance in the exchanges established under the Affordable Care Act. Using statewide hospital discharge data, we show that Medicaid-funded hospitalizations and emergency room visits declined in this population by 31% and 19%, respectively. Utilization funded by private insurance did increase but not enough to offset the declines in Medicaid-funded utilization. We show that the expiration of benefits increased uninsured ER visits. Finally, we exploit a feature of the policy change to provide evidence that the declines in utilization are due to higher rates of uninsured migrants rather than higher levels of cost sharing on private plans.