Maria Polyakova

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

E-Mail: EmailAddress: hidden: you can email any NBER-related person as first underscore last at nber dot org
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.

Published: Liran Einav & Amy Finkelstein & Maria Polyakova, 2018. "Private Provision of Social Insurance: Drug-Specific Price Elasticities and Cost Sharing in Medicare Part D," American Economic Journal: Economic Policy, vol 10(3), pages 122-153.

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 2015Subsidy Design in Privately-Provided Social Insurance: Lessons from 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 strategic insurers and the subsidy mechanism. We study this interaction in the context of Medicare's prescription drug coverage program. We find that the observed mechanism is successful in keeping "raise-the-subsidy" incentives relatively low, acts much like a at voucher, and obtains a level of welfare close to the optimal voucher. Across a range of counterfactuals, we find that more efficient subsidy mechanisms share three features: they retain the marginal elasticity of demand, limit the exercise of market power, and preserve the link between prices and marginal costs.
NBER Videos

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email:

Contact Us