Maria Polyakova

Department of Health Research & Policy
Stanford University
Redwood Building T111
150 Governor's Lane
Stanford, CA 94305
Tel: 650/498-7528

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NBER Program Affiliations: HC
NBER Affiliation: Faculty Research Fellow

NBER Working Papers and Publications

May 2016Private Provision of Social Insurance: Drug-specific Price Elasticities and Cost Sharing in Medicare Part D
with Liran Einav, Amy Finkelstein: w22277
Standard theory suggests that optimal consumer cost-sharing in health insurance increases with the price elasticity of demand, yet publicly-provided drug coverage typically involves uniform cost-sharing across drugs. We investigate how private drug plans set cost-sharing in the context of Medicare Part D. We document substantial heterogeneity in the price elasticities of demand across more than 150 drugs and across more than 100 therapeutic classes, as well as substantial heterogeneity in the cost-sharing for different drugs within privately-provided plans. We find that private plans set higher consumer cost-sharing for drugs or classes with more elastic demand. Our findings suggest that benefit design may be more efficient in privately rather than publicly provided insurance.
September 2015Regulation of Insurance with Adverse Selection and Switching Costs: Evidence from Medicare Part D.
I take advantage of regulatory and pricing dynamics in Medicare Part D to empirically explore interactions among adverse selection, switching costs, and regulation. I first document novel evidence of adverse selection and switching costs within Part D using detailed administrative data. I then estimate a contract choice and pricing model in order to quantify the importance of switching costs for risk-sorting, and for policies that may affect risk sorting. I first find that in Part D, switching costs help sustain an adversely-selected equilibrium and are likely to mute the ability of ACA policies to improve risk allocation across contracts, leading to higher premiums for some enrollees. I then estimate that, overall, decreasing the cost of active decision-making in the Part D environment co...

Published: Maria Polyakova, 2016. "Regulation of Insurance with Adverse Selection and Switching Costs: Evidence from Medicare Part D," American Economic Journal: Applied Economics, American Economic Association, vol. 8(3), pages 165-95, July. citation courtesy of

June 2015The Welfare Effects of Supply-Side Regulations in Medicare Part D
with Francesco Decarolis, Stephen P. Ryan: w21298
The efficiency of publicly-subsidized, privately-provisioned social insurance programs depends on the interaction between insurer behavior and public subsidies. We study this interaction within Medicare Part D Prescription Drug Plan (PDP) markets. Using a structural model of supply and demand, we find: consumers purchase too few and too socially-costly PDP plans; insurers price near marginal cost; the primary driver of welfare is the opportunity cost of government spending on other Medicare programs; and the current subsidization policy achieves a level of total welfare close to that obtained under an optimal in-kind subsidy, but is far from the social planner's first-best solution.
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