Academic Appointments

Professional Education

  • Ph.D., MIT, Economics (2014)
  • B.A., Yale University, Economics & Mathematics (2008)

2023-24 Courses

Stanford Advisees

All Publications

  • Association of Family Income With Morbidity and Mortality Among US Lower-Income Children and Adolescents. JAMA Udalova, V., Bhatia, V., Polyakova, M. 2022; 328 (24): 2422-2430


    Importance: Family income is known to be associated with children's health; the association may be particularly pronounced among lower-income children in the US, who tend to have more limited access to health resources than their higher-income peers.Objective: To investigate the association of family income with claims-based measures of morbidity and mortality among children and adolescents in lower-income families in the US enrolled in Medicaid or the Children's Health Insurance Program.Design, Setting, and Participants: This cross-sectional analysis included 795 000 participants aged 5 to 17 years enrolled in Medicaid (Medicaid Analytic eXtract claims, 2011-2012) living in families with income below 200% of the federal poverty threshold (American Community Survey, 2008-2013). Follow-up ended in December 2021.Exposures: Family income relative to the federal poverty threshold.Main Outcomes and Measures: Record of International Classification of Diseases, Ninth Revision codes for an infection, mental health disorder, injury, asthma, anemia, or substance use disorder and death record within 10 years of observation (Social Security Administration death records through 2021).Results: Among 795 000 individuals in the sample (all statistics weighted: mean [SD] income-to-poverty ratio, 90% [53%]; mean [SD] age, 10.6 [3.9] years; 56% aged 10 to 17 years), 33% had a diagnosed infection, 13% had a mental health disorder, 6% had an injury, 5% had asthma, 2% had anemia, 1% had a substance use disorder, and 0.6% died between 2011 and 2021, with the mean (SD) age at death of 19.8 (4.2) years. For those aged 5 to 9 years, higher family income was associated with lower adjusted prevalence of all outcomes, except mortality: children in families with an additional 100% income relative to the federal poverty threshold had 2.3 (95% CI, 1.8-2.9) percentage points fewer infections, 1.9 (95% CI, 1.5-2.2) percentage points fewer mental health diagnoses, 0.7 (95% CI, 0.5-0.8) percentage points fewer injuries, 0.3 (95% CI, 0.09-0.5) percentage points less asthma, 0.2 (95% CI, 0.08-0.3) percentage points less anemia, and 0.06 (95% CI, 0.03-0.09) percentage points fewer substance use disorder diagnoses. Except for injury and anemia, the associations were more pronounced among those aged 10 to 17 years than those 5 to 9 years (P for interaction <.05). For those aged 10 to 17 years, an additional 100% income relative to the federal poverty threshold was associated with a lower 10-year mortality rate by 0.18 (95% CI, 0.12-0.25) percentage points.Conclusions and Relevance: Among children and adolescents in the US aged 5 to 17 years with family income under 200% of the federal poverty threshold who accessed health care through Medicaid or the Children's Health Insurance Program, higher family income was significantly associated with a lower prevalence of diagnosed infections, mental health disorders, injury, asthma, anemia, and substance use disorders and lower 10-year mortality. Further research is needed to understand whether these associations are causal.

    View details for DOI 10.1001/jama.2022.22778

    View details for PubMedID 36573975

  • The Roots of Health Inequality and the Value of Intrafamily Expertise AMERICAN ECONOMIC JOURNAL-APPLIED ECONOMICS Chen, Y., Persson, P., Polyakova, M. 2022; 14 (3): 185-223
  • Analysis of Publicly Funded Reinsurance-Government Spending and Insurer Risk Exposure. JAMA health forum Polyakova, M., Bhatia, V., Bundorf, M. K. 2021; 2 (8): e211992


    This analysis compares the design of section 1332 reinsurance policies across states based on their potential for reducing insurer risk exposure and likely level of government spending.

    View details for DOI 10.1001/jamahealthforum.2021.1992

    View details for PubMedID 35977191

    View details for PubMedCentralID PMC8796983

  • Racial Disparities In Excess All-Cause Mortality During The Early COVID-19 Pandemic Varied Substantially Across States. Health affairs (Project Hope) Polyakova, M., Udalova, V., Kocks, G., Genadek, K., Finlay, K., Finkelstein, A. N. 2021; 40 (2): 307–16


    The impact of the coronavirus disease 2019 (COVID-19) pandemic has been starkly unequal across race and ethnicity. We examined the geographic variation in excess all-cause mortality by race and ethnicity to better understand the impact of the pandemic. We used individual-level administrative data on the US population between January 2011 and April 2020 to estimate the geographic variation in excess all-cause mortality by race and Hispanic origin. All-cause mortality allows a better understanding of the overall impact of the pandemic than mortality attributable to COVID-19 directly. Nationwide, adjusted excess all-cause mortality during that period was 6.8 per 10,000 for Black people, 4.3 for Hispanic people, 2.7 for Asian people, and 1.5 for White people. Nationwide averages mask substantial geographic variation. For example, despite similar excess White mortality, Michigan and Louisiana had markedly different excess Black mortality, as did Pennsylvania compared with Rhode Island. Wisconsin experienced no significant White excess mortality but had significant Black excess mortality. Further work understanding the causes of geographic variation in racial and ethnic disparities-the relevant roles of social and environmental factors relative to comorbidities and of the direct and indirect health effects of the pandemic-is crucial for effective policy making.

    View details for DOI 10.1377/hlthaff.2020.02142

    View details for PubMedID 33523748

  • Does medicine run in the family-evidence from three generations of physicians in Sweden: retrospective observational study. BMJ (Clinical research ed.) Polyakova, M., Persson, P., Hofmann, K., Jena, A. B. 2020; 371: m4453


    OBJECTIVE: To examine occupational heritability in medicine and changes in heritability over time, with Swedish population wide administrative data that allowed mapping family trees of physicians spanning up to three generations.DESIGN: Retrospective observational study.SETTING: Individual level administrative registry data from Sweden.PARTICIPANTS: Physicians born in 1950-90 and living in Sweden at some time during 2001-16 (n=47400).MAIN OUTCOME MEASURES: The proportion of individuals with a completed medical degree with at least one parent who also trained in medicine, and the change in this proportion across birth cohorts. Additional analyses were conducted among other relatives (grandparents, aunts and uncles, and siblings) and for individuals with a law degree.RESULTS: For 27788 physicians, where the educational background for both parents was known, 14% had a parent who was also a physician and 2% had two parents who were physicians. The proportion of physicians with at least one physician parent increased significantly over time, from 6% for physicians born in 1950-59 to 20% for physicians born in 1980-90 (P<0.001). The same pattern of increasing occupational heritability was not seen for individuals with law degrees.CONCLUSIONS: In recent cohorts of physicians in Sweden, one in five had a parent who was also a physician, more than triple the proportion seen for physicians born three decades earlier. A similar pattern was not seen in lawyers, suggesting that increasing occupational heritability in medicine does not reflect intergenerational persistence of high paying degrees alone. Rather, for physicians in Sweden, medicine might increasingly run in families.

    View details for DOI 10.1136/bmj.m4453

    View details for PubMedID 33328192

  • Initial economic damage from the COVID-19 pandemic in the United States is more widespread across ages and geographies than initial mortality impacts. Proceedings of the National Academy of Sciences of the United States of America Polyakova, M., Kocks, G., Udalova, V., Finkelstein, A. 2020


    The economic and mortality impacts of the COVID-19 pandemic have been widely discussed, but there is limited evidence on their relationship across demographic and geographic groups. We use publicly available monthly data from January 2011 through April 2020 on all-cause death counts from the Centers for Disease Control and Prevention and employment from the Current Population Survey to estimate excess all-cause mortality and employment displacement in April 2020 in the United States. We report results nationally and separately by state and by age group. Nationally, excess all-cause mortality was 2.4 per 10,000 individuals (about 30% higher than reported COVID deaths in April) and employment displacement was 9.9 per 100 individuals. Across age groups 25 y and older, excess mortality was negatively correlated with economic damage; excess mortality was largest among the oldest (individuals 85 y and over: 39.0 per 10,000), while employment displacement was largest among the youngest (individuals 25 to 44 y: 11.6 per 100 individuals). Across states, employment displacement was positively correlated with excess mortality (correlation = 0.29). However, mortality was highly concentrated geographically, with the top two states (New York and New Jersey) each experiencing over 10 excess deaths per 10,000 and accounting for about half of national excess mortality. By contrast, employment displacement was more geographically spread, with the states with the largest point estimates (Nevada and Michigan) each experiencing over 16 percentage points employment displacement but accounting for only 7% of the national displacement. These results suggest that policy responses may differentially affect generations and geographies.

    View details for DOI 10.1073/pnas.2014279117

    View details for PubMedID 33082229

  • Subsidy Design in Privately Provided Social Insurance: Lessons from Medicare Part D. The journal of political economy Decarolis, F. n., Polyakova, M. n., Ryan, S. P. 2020; 128 (5): 1712–52


    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 flat 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.

    View details for DOI 10.1086/705550

    View details for PubMedID 32431365

    View details for PubMedCentralID PMC7236560

  • Local Area Variation in Morbidity Among Low-Income, Older Adults in the United States: A Cross-sectional Study. Annals of internal medicine Polyakova, M., Hua, L. M. 2019


    Background: Recent studies have reported that low-income adults living in more affluent areas of the United States have longer life expectancies. Less is known about the relationship between the affluence of a geographic area and morbidity of the low-income population.Objective: To evaluate the association between the prevalence of chronic conditions among low-income, older adults and the economic affluence of a local area.Design: Cross-sectional association study.Setting: Medicare in 2015.Participants: 6363097 Medicare beneficiaries aged 66 to 100 years with a history of low-income support under Medicare Part D.Measurements: Adjusted prevalence of 48 chronic conditions was computed for 736 commuting zones (CZs). Factor analysis was used to assess spatial covariation of condition prevalence and to construct a composite condition prevalence index for each CZ. The association between morbidity and area affluence was measured by comparing the average of condition prevalence index across deciles of median CZ house values.Results: The mean age of study participants was 77.7 years (SD, 8.2); 67% were women, and 61% were white. The crude prevalence of 48 chronic conditions ranged from 72.5 per 100 for hypertension to 0.6 per 100 for posttraumatic stress disorder. The prevalence of these 48 chronic conditions was highly spatially correlated. Composite condition prevalence was on average substantially lower in more affluent CZs.Limitation: Low-income status measured on the basis of receipt of Medicare Part D low-income subsidies and not capturing persons not enrolled in Medicare Part D.Conclusion: Low-income, older adults living in more affluent areas of the country are healthier, and areas with poor health in the low-income, older adult population tend to have a high prevalence of most chronic conditions.Primary Funding Source: National Institute on Aging.

    View details for DOI 10.7326/M18-2800

    View details for PubMedID 31499522

  • Machine-Based Expert Recommendations And Insurance Choices Among Medicare Part D Enrollees HEALTH AFFAIRS Bundorf, M., Polyakova, M., Stults, C., Meehan, A., Klimke, R., Pun, T., Chan, A., Tai-Seale, M. 2019; 38 (3): 482–90
  • Private Provision of Social Insurance: Drug-Specific Price Elasticities and Cost Sharing in Medicare Part D AMERICAN ECONOMIC JOURNAL-ECONOMIC POLICY Einav, L., Finkelstein, A., Polyakova, M. 2018; 10 (3): 122–53
  • ACA Marketplace Premiums and Competition Among Hospitals and Physician Practices AMERICAN JOURNAL OF MANAGED CARE Polyakova, M., Bundorf, M., Kessler, D. P., Baker, L. C. 2018; 24 (2): 85-+


    To examine the association between annual premiums for health plans available in Federally Facilitated Marketplaces (FFMs) and the extent of competition and integration among physicians and hospitals, as well as the number of insurers.We used observational data from the Center for Consumer Information and Insurance Oversight on the annual premiums and other characteristics of plans, matched to measures of physician, hospital, and insurer market competitiveness and other characteristics of 411 rating areas in the 37 FFMs.We estimated multivariate models of the relationship between annual premiums and Herfindahl-Hirschman indices of hospitals and physician practices, controlling for the number of insurers, the extent of physician-hospital integration, and other plan and rating area characteristics.Premiums for Marketplace plans were higher in rating areas in which physician, hospital, and insurance markets were less competitive. An increase from the 10th to the 90th percentile of physician concentration and hospital concentration was associated with increases of $393 and $189, respectively, in annual premiums for the Silver plan with the second lowest cost. A similar increase in the number of insurers was associated with a $421 decrease in premiums. Physician-hospital integration was not significantly associated with premiums.Premiums for FFM plans were higher in markets with greater concentrations of hospitals and physicians but fewer insurers. Higher premiums make health insurance less affordable for people purchasing unsubsidized coverage and raise the cost of Marketplace premium tax credits to the government.

    View details for PubMedID 29461855

  • Marketplace Plans Provide Risk Protection, But Actuarial Values Overstate Realized Coverage For Most Enrollees HEALTH AFFAIRS Polyakova, M., Hua, L., Bundorf, M. 2017; 36 (12): 2078–84
  • Risk selection and heterogeneous preferences in health insurance markets with a public option JOURNAL OF HEALTH ECONOMICS Polyakova, M. 2016; 49: 153-168


    Conventional wisdom suggests that if private health insurance plans compete alongside a public option, they may endanger the latter's financial stability by cream-skimming good risks. This paper argues that two factors may contribute to the extent of cream-skimming: (i) degree of horizontal differentiation between public and private options when preferences are heterogeneous; (ii) whether contract design encourages choice of private insurance before information about risk is revealed. I explore the role of these factors empirically within the unique institutional setting of the German health insurance system. Using a fuzzy regression discontinuity design to disentangle adverse selection and moral hazard, I find no compelling support for extensive cream-skimming of public option by private insurers despite their ability to fully underwrite risk. A model of demand for private insurance supports the idea that heterogeneity in non-pecuniary preferences and long-term structure of private insurance contracts may be muting cream-skimming in this setting.

    View details for DOI 10.1016/j.jhealeco.2016.06.012

    View details for Web of Science ID 000384869400012

    View details for PubMedID 27454199

  • Regulation of Insurance with Adverse Selection and Switching Costs: Evidence from Medicare Part D AMERICAN ECONOMIC JOURNAL-APPLIED ECONOMICS Polyakova, M. 2016; 8 (3): 165-195