Research

The dynamic effect of an additional representative in Congress on all-cause mortality in the months following the disbursement of pandemic aid to states and local governments

The COVID-19 pandemic led to unprecedented levels of federal transfers to state and local governments. Did this funding impact population health? To answer this question, we leverage the fact that U.S. states that enjoy excess representation in Congress received substantially more fiscal assistance than did relatively underrepresented states. We find that the aid driven by excess representation had substantial impacts on population health. For each $1,000 increase in federal fiscal aid per state resident, we estimate that states experienced 38 fewer deaths from all causes per 100,000 residents from 2020 through 2022, of which 2/3 came from reductions in COVID-19 mortality. Additional aid also reduced rates of COVID-19 related hospitalizations and emergency room visits, though not in the total number of positive cases detected. Plausible mechanisms for these improved outcomes include substantially higher rates of COVID-19 testing and moderately higher COVID-19 vaccination rates. Medicaid enrollments and hospital capacity do not appear to play substantial mediating roles. Our robustness analyses provide evidence that the effects we estimate cannot be explained by pre-existing mortality trends, by the pandemic's differential impacts on relatively dense vs. rural areas, or by the pandemic's differential impacts on populations with more elderly individuals or with higher prevalence of chronic conditions. The mortality impacts we estimate were substantially greater for non-Hispanic Black Americans than for non-Hispanic White Americans, such that federal funds are associated with a reduction in population-wide health disparities over the course of the pandemic.

The effect of a minimum wage increase on Medicaid participation

I examine the effects of the interaction between minimum wage increases and the Affordable Care Act Medicaid expansion policy on Medicaid take-up. I find that contrary to mechanical predictions, minimum wage hikes result in increased Medicaid take-up in all states. But I suggest that the mechanisms causing these effects differ between Medicaid expansion and non-expansion states. Increases in Medicaid take-up in Medicaid expansion states are more consistent with crowd-out of private insurance – faced with higher labor costs, employers take advantage of the availability of Medicaid and reduce the generosity of employer sponsored insurance, prompting workers’ substitution towards Medicaid. In Medicaid non-expansion states, increases in Medicaid take-up are more consistent with reductions in uninsurance – minimum wage increases are not associated with reductions in employer-sponsored insurance but with losses of benefits from other public programs. Consequently, previously uninsured workers take up Medicaid to replace the lost benefits. Overall, minimum wage increases affect the mix of benefits a worker receives from the government and firms, and could have downstream health effects through changes in this mix.

Medicaid enrollment in the U.S. during and after the COVID-19 pandemic

Due to the implementation and unwinding of a “continuous coverage requirement”, the COVID-19 pandemic gave rise to the most dramatic changes in Medicaid enrollments in the program’s history. Nationwide, enrollments rose by 23 million individuals from February 2020 through March 2023, then declined by roughly 15 million by late 2024. Notably, changes in per capita enrollments varied dramatically across the country, with several states experiencing net declines and several states seeing their enrollments rise, on net, by more than 5 percent of their populations. Through a mix of descriptive and causal analyses, we explore several hypotheses regarding the possible causes of these variations. We find that a wide range of provisions designed to ease the frictions of the continuous coverage provision’s winding down have surprisingly little predictive power.  Similarly, we find that variations in federal aid to state and local governments has no predictive power, suggesting that liquidity constraints had little influence on states’ management of Medicaid enrollments during this period. Variations in political preferences, as proxied by Trump’s 2016 vote share, have modest predictive power within the unwinding episode. Finally, states that enacted Medicaid expansions during the pandemic experienced relatively large net gains in enrollments. The baseline generosity of states’ eligibility thresholds also predicts relatively large run-ups and net increases in enrollments.

Growth in the population share covered by accountable care organizations between 2011 and 2015

Accountable care organizations (ACOs) were created as a provision of the Affordable Care Act in 2010 where a group of physicians, hospitals and other healthcare professionals collaborate to take responsibility for patient care and cost savings. The share of the population covered by accountable care organizations (ACOs) is growing, but the association between this increase and physician employment is unknown. In this paper we investigate the association between the growth of ACOs and changes in physician work hours, probability of being self-employed, and probability of working in a hospital. Using data from the ACS covering the years 2011 to 2015, we use  a cross-sectional fixed-effects design to compare changes in physician employment in hospital referral regions with high vs low ACO growth.  We find that a 10–percentage point increase in ACO enrollment in a hospital referral region is associated with a statistically significant reduction of 0.82 work hours in men and a decrease of 2% in the probability of all physicians being self-employed. The association with self-employment is strongest in physicians aged 50 to 69 years, who are also more likely to work in a hospital. These results suggest that ACOs may affect physician employment patterns.

The effect of a merger on dialysis facilities in a market by firm type