اثر هزینه های پزشک خدمات درمانی در بالا بردن بیمه سلامت عمومی در میان کودکان فقیر

I investigate how changes in fees paid to Medicaid physicians affect take-up among children in low-income families. The existing literature suggests that the low level of Medicaid fee payments to physicians reduces their willingness to see Medicaid patients, thus creating an access-to-care problem for these patients. For the identical service, current Medicaid reimbursement rates are only about 65 percent of those covered by Medicare. Increasing the relative payments of Medicaid would increase its perceived value, as it would provide better access to health care for Medicaid beneficiaries. Using variation in the timing of the changes in Medicaid payment across states, I find that increasing Medicaid generosity is associated with both an increase in take-up and a reduction in uninsured rate. These results provide a partial answer to the puzzling question of why many low-income children who are eligible for Medicaid remain uninsured.

Medicaid was created in 1965 to provide virtually free public health insurance to low-income individuals in the United States. Although most children below the poverty line are eligible for public insurance through several federally mandated programs, the uninsured rate in this group has remained high, at almost double that of children above the poverty line.1 This puzzling phenomenon of ‘eligible but not enrolled’ under means-tested social insurance and transfer programs has motivated a good deal of research in identifying factors that affect take-up. The previous literature has proposed several explanations for individuals not participating in public programs even when they are eligible for benefits. Although the monetary costs of enrolling in Medicaid are almost zero as Medicaid entails virtually no out-of-pocket costs, individuals may face nonmonetary costs when they enroll in the public program, including the stigma attached to public insurance and administrative hassles (Remler et al., 2001). There are also informational barriers, particularly if potential enrollees have not used public programs before (Aizer, 2007 and Kenney and Haley, 2001). In this paper, I offer a new perspective on the take-up of Medicaid. The previous literature on the determinants of Medicaid take-up has largely focused on the cost of enrolling in public programs. This current study departs from the previous literature by focusing on how the value of Medicaid affects take-up. In particular, I examine the relationship between take-up and patient access to care, using the Medicaid-to-Medicare fee index as a proxy for access to care provided by Medicaid. Historically, Medicaid reimbursement levels for physicians are low. As a result, physicians are not incentivized to treat Medicaid patients, and this creates access-to-care problems for this group. In fact, 20 percent of pediatricians in the United States do not see Medicaid patients at all, and 40 percent limit the number of Medicaid patients in their practice (Currie and Fahr, 2005). All else being equal, increasing the Medicaid payment to physicians would lead to a higher participation rate among physicians. Past studies have both theoretically posited and empirically tested this positive relationship between Medicaid payment and physician participation (McGuire and Pauly, 1991, Perloff et al., 1995 and Decker, 2007). One valid conjecture then is how increased physician participation, which is induced from an increase in Medicaid reimbursement, affects the decision faced by potential Medicaid beneficiaries. If the potential beneficiaries weigh the cost against the benefit of enrolling in Medicaid and decide to take-up only when the benefit exceeds the cost, then the increase in access to care would encourage higher enrollment rates among the Medicaid-eligible. This paper is the first to explore the relationship between patients’ access to care and take-up. I focus on the effect of access to care on the health insurance status among poor children, since this is the population that is both most likely to suffer from access problems and most vulnerable to financial and health shocks. The effect of improved access to care on take-up among poor children is identified by exploiting within-state variation over time in the Medicaid-to-Medicare primary fee index. I find that increasing the Medicaid fee payments from 65 percent to 100 percent of the Medicare level increases the take-up rate among poor children by 4.8 percentage points and decreases the uninsured rate by 6.2 percentage points, thus reducing the uninsured rate in this group by almost 30 percent. Therefore, improving access to care through increased physician reimbursements can be an effective way to provide health insurance coverage to uninsured low-income children. The paper proceeds as follows. Section 2 lays out the potential mechanisms by which the increase in Medicaid provider payment improves access to care and eventually leads to an increase in take-up. Section 3 describes the measure for access to care and the main dataset. In Section 4, I specify estimation strategies. Section 5 reports results for baseline specification and the specifications that control for various time-varying state policies. Section 6 addresses potential identification issues by reporting results for robustness checks and placebo tests. Section 7 concludes by discussing the policy implications of the findings in this paper.

Even though the existing literature and anecdotal evidence suggest that Medicaid’s low rate of payment hurts physician incentives to treat Medicaid patients, relatively little is known about the role of access to care on the take-up of public health insurance. In this paper, I use the Medicaid-to-Medicare fee index for primary care services (in 1993, 1998 and 2003) as a proxy for access to care to investigate the effect of Medicaid fees on the health insurance coverage. Understanding whether an increase in the Medicaid fee can be an effective policy lever to promote take-up is crucial in the current situation where states have substantial discretion over setting the fee paid to physicians and hospitals. Increases in fees have a beneficial effect on ensuring higher quality and more timely access to care, while at the same time reducing the uninsured rate. No evidence is found that higher Medicaid fee promotes the crowd-out of private insurance among poor children, as the Medicaid fee ratio fails to predict the likelihood of being covered by private insurance. The most conservative finding in this paper suggests that an increase in the Medicaid-to-Medicare fee index by 10 percentage points (about a half of standard deviation of the fee index) is associated with a decrease in the uninsured rate by 1.24 percentage points within the low-income population. As about 41 percent of the 9 million uninsured children are in poverty (and thus eligible for Medicaid), the finding indicates that a 10 percentage point increase in fee payments would lead to a reduction of about 45,800 low-income uninsured children. Increasing physician fees would be costly, but movement of care from hospital-based settings (outpatient and emergency departments) to physician offices might offset some part of the costs since fees for care in hospital-based settings tend to be higher.22