Research

“Adverse Selection (un)Natural Monopoly in Insurance Markets” (with Timothy Layton and Edward Kong)
Links: NBER Working Paper #33187
Reject & Resubmit, Quarterly Journal of Economics

“Unobserved Heterogeneity, State Dependence, and Health Plan Choices,” 2022 (with Ariel Pakes, Jack Porter, and Sophie Calder-Wang). 

   Links: NBER Working Paper #29025
Reject & Resubmit, American Economic Review

Economics Journals

Shepard, Mark, & Myles Wagner. (2025). “Do ordeals work for selection markets? Evidence from health insurance auto-enrollment.” American Economic Review, 115(3), 772-822. [Online Appendix] [Replication Packet] [NBER Working Paper]

Kreider, Amanda R., Timothy J. Layton, Mark Shepard, and Jacob Wallace. “Adverse selection and network design under regulated plan prices: Evidence from Medicaid.” Journal of Health Economics 97 (2024): 102901. [Publisher's Site] [NBER Working Paper #30719]

Baicker, Katherine, Amitabh Chandra, and Mark Shepard. 2023. “Achieving Universal Health Insurance Coverage in the United States: Addressing Market Failures or Providing a Social Floor?” Journal of Economic Perspectives 37(2): 99-122. [Links: Publication Site; NBER Working Paper]

Geruso, Michael, Timothy Layton, Grace McCormack, and Mark Shepard. 2023. “The Two Margin Problem in Insurance Markets.” Review of Economics and Statistics 105 (2): 237-257. [Links: NBER Working Paper]

Shepard, Mark, and Ethan Forsgren. 2023. “Do Insurers Respond to Active Purchasing? Evidence from the Massachusetts Health Insurance Exchange.” Journal of Risk and Insurance 90(1): 9-31. [Links: Published version]

Shepard, Mark. 2022. “Hospital Network Competition and Adverse Selection: Evidence from the Massachusetts Health Insurance Exchange.” American Economic Review 112 (2): 578-615. [Links: Publication Site; Online Appendix; Replication Packet; NBER WP (with additional structural work)]

McIntyre, Adrianna, Mark Shepard, and Myles Wagner. 2021. “Can Automatic Retention Improve Health Insurance Market Outcomes?” American Economic Association, Papers & Proceedings, 111: p. 560-66. [Links: Publication, NBER WP]

Jaffe, Sonia and Mark Shepard. 2020. “Price-Linked Subsidies and Imperfect Competition in Health Insurance.” American Economic Journal: Economic Policy 12(3): 279-311. [Links: Online Appendix; Replication Packet; NBER Working Paper]

Finkelstein, Amy, Nathaniel Hendren, and Mark Shepard. 2019. “Subsidizing health insurance for low-income adults: Evidence from Massachusetts.” American Economic Review 109, no. 4: 1530-1567. [Links: Publication Site; Online Appendix; Replication Packet; NBER Working Paper]

Ho, Kate, Ariel Pakes, and Mark Shepard. “The evolution of health insurer costs in Massachusetts, 2010–2012.” Review of Industrial Organization 53, no. 1 (2018): 117-137.  [Links: Publication Site; NBER Working Paper]

Health Policy Journals

McIntyre, Adrianna, Mark Shepard, and Timothy Layton. 2024. “Small Marketplace Premiums Pose Financial and Administrative Burdens: Evidence from Massachusetts, 2016–17.” Health Affairs 43 (1). (Link: Published version)

Baicker, Katherine, Amitabh Chandra, and Mark Shepard (2023). “A Different Framework to Achieve Universal Coverage in the US.” JAMA Health Forum 2023; 4(2):e230187. doi:10.1001/jamahealthforum.2023.0187. (Link: Published version)

Kong, Ed, Mark Shepard, and Adrianna McIntyre (2022). “Turnover in Zero-Premium Status Among Health Insurance Marketplace Plans Available to Low-Income Enrollees.” JAMA Health Forum (Vol. 3, No. 4, pp. e220674-e220674). (Published version)

McIntyre, Adrianna and Mark Shepard. (2022). “Automatic insurance policies – important tools for preventing coverage loss.” The New England Journal of Medicine, 386(5), 408-411. (Published version)

Sommers, Benjamin D., Mark Shepard, and Katherine Hempstead. “Why Did Employer Coverage Fall In Massachusetts After The ACA? Potential Consequences Of A Changing Employer Mandate.” Health Affairs 37, no. 7 (2018): 1144-1152.   (Link: Publication)

Baicker, Katherine, Mark Shepard, and Jonathan Skinner. “Public financing of the Medicare program will make its uniform structure increasingly costly to sustain.” Health Affairs 32, no. 5 (2013): 882-890.  (Link: Publication)

Brennan, Niall, and Mark Shepard. “Comparing quality of care in the Medicare program.” The American Journal of Managed Care 16, no. 11 (2010): 841-848.  (Link: Publication)

Shepard, Mark, Katherine Baicker, and Jonathan Skinner. “Does One Medicare Fit All? The Economics of Uniform Health Insurance Benefits.” In Robert A. Moffitt ed., Tax Policy and the Economy vol. 34 (2020): 1-41. 
Links: Paper, Published volume

Layton, Timothy, Alice Ndikumana, and Mark Shepard. “Health plan payment in Medicaid Managed Care: A Hybrid Model of Regulated Competition.” In Risk Adjustment, Risk Sharing, and Premium Regulation in Health Insurance Markets: Theory and Practice, edited by Thomas McGuire and Richard van Kleef. Cambridge, MA: Elsevier, 2018. (Also available as NBER Working Paper #23518)

Layton, Timothy, Ellen Montz, and Mark Shepard. “Health Plan Payment in U.S. Marketplaces: Regulated Competition with a Weak Mandate.” In Risk Adjustment, Risk Sharing, and Premium Regulation in Health Insurance Markets: Theory and Practice, edited by Thomas McGuire and Richard van Kleef. Cambridge, MA: Elsevier, 2018. (Also available as NBER Working Paper #23444) 

Shepard, Mark. 2011. "Social Security Claiming and the Annuity Puzzle." Working Paper.

“Strategic Auto-Enrollment and Health Insurance Market Design,” (with Kai Shen Lim and Myles Wagner)

“The Social Value of Health Insurance” (with Tim Layton, Samantha Burn, and Jingwei Sun)

“Insurance Billing Frictions and Health Care Markets?” (with Riley League and Myles Wagner)

“Understanding Geographic Variations in Medicaid and Medicare-Medicaid differences” (with Timothy Layton, Nicole Maestas, Daniel Prinz, and Boris Vabson)