My current curriculum vitae

Academic Papers and Publications

Peer Reviewed Publications

  • “Coverage retention and plan switching following switches from a zero- to a positive-premium plan.” JAMA Health Forum. (accepted for publication March 2025) (with Coleman Drake, Dylan Nagy, Sarah Avina, and David M. Anderson)
    Question: Do lower income Health Insurance Marketplace enrollees lose or change coverage when they experience “turnover” and are defaulted from a zero-premium silver plan to a silver plan with a premium?
    Findings: Zero- to positive-premium plan turnover was associated with an approximately 7% decrease in automatic reenrollment. Turnover also was associated with a roughly 14% increase in enrollees selecting new plans in lieu of their prior plans.
    Meaning: Defaulting lower income Marketplace enrollees from zero- to positive-premium plans reduces automatic reenrollment and prompts some returning enrollees to select a new plan rather than staying with their prior plan.
  • “Incremental Cost of State Funds for New Enrollment in Section 1332 Waivers.” Health Affairs Scholar. (accepted for publication February 2025) (with David M. Anderson)
    The Affordable Care Act (ACA) allows states to modify their state individual health insurance market with Section 1332 waivers. Section 1332 reinsurance lowers unsubsidized premiums in the ACA individual health insurance markets as state funds pay for some high-cost claims. These lower premiums decrease the cost of premium tax credits for the federal government which then passes these savings to the state government. By December 1, 2024, sixteen states received Section 1332 waivers from the federal government to enact state funded reinsurance programs and all prioritized increasing enrollment in health insurance in their initial applications. Lowering the premium for health insurance has two effects on consumer behavior. First, it reduces costs for existing buyers who do not receive subsidies. This is significant because premium costs for individuals who do not receive federal financial assistance have consistently increased since 2014. This group benefits from a decrease in their out-of-pocket expenses, which can improve their overall financial stability and access to healthcare services. Second, a lower premium decreases the minimum cost of coverage for individuals who previously found health insurance premiums to be unaffordable. These individuals, who previously would not have purchased insurance due to high costs, may now decide to purchase ACA health insurance. This analysis is focused on this group of newly insured individuals and compares the extra state costs, defined as only the state expenditures without regard to federal pass-through funding, to the expected increase in enrollment.
  • “Dynamic Price Competition for Low-Cost Silver Plans on Healthcare.Gov 2014–2021.” Medical Care Research and Review, July 2, 2023. (with David M. Anderson)
    • More than 16 million people receive health care coverage through the Affordable Care Act’s (ACA) individual health insurance marketplaces. Many enrollees receive premium subsidies that are tied to the premium of the second least expensive silver plan available. This study investigates the consistency of the least expensive silver plan offered on Healthcare.gov from 2014 to 2021 and finds that on average, from one year to the next, the same insurer offered the least expensive silver plan in 63.1% of counties representing 54.7% of the population. However, even when the same insurer offers the least expensive plan, almost half the time, they introduce a new, less expensive plan in the next policy year. Consequently, ACA enrollees who previously purchased the least expensive silver plan may face incremental premium costs unless they spend time and effort to carefully reevaluate their choices each year. We estimate the potential premium cost of inattention and show how it varies over time and across states.
  • “Antitrust and Accountable Care Organizations: Observations for the Physician Market.” Medical Care Research and Review, January 2016, 1077558715627554. (with Samuel A. Kleiner and William D. White)
    • The creation of Accountable Care Organizations (ACOs) under the Medicare Shared Savings Program has generated antitrust concerns. Utilizing a framework developed by the antitrust authorities for analyzing provider concentration for potential ACO participants, we examine the market for physician services, with a focus on the share of practices that could potentially be subject to antitrust scrutiny. Our findings suggest that while most physician practices would fall below the threshold that could raise anticompetitive concerns, this varies considerably by market and specialty. Furthermore, we find that the largest physician practice in most markets potentially remains at risk for antitrust review under the existing criteria.
  • “Environmental and health impacts from the introduction of improved wood stoves: evidence from a field experiment in Guatemala.” Environment, Development and Sustainability 13, no. 4 (2011): 657-676. (with Kent Moriarty, and Bruce Wydick)
    • Improved wood-burning stoves offer a possible solution that can simultaneously impact both problems of deforestation and problems of respiratory health in developing countries. We carried out a field experiment in which new fuel-efficient woodstoves were allocated in a Guatemalan village via the use of a lottery. A 2008 baseline survey was carried out on 2,148 individuals in 351 households, and then a follow-up survey was carried out in 2009, 4 months after households received the stoves. We found that households with the new stoves reduced wood consumption by an average of 59.1%. We also found indications of reductions in indoor air related health problems, where point estimates indicate a significant reduction in reported respiratory symptoms by 48.6% among women and 63.3% among children.

Working Papers

Works in Progress:

  • Insurer Market Structure as a Determinate of Physician Practice Size (view current working paper)
  • Who does what? An Analysis of the Relationship Between Physicians’ Specialties and Procedures (preview)
  • Did Medicare Accountable Care Organizations Increase Integration? A Look at Patient Sharing Patterns