Research

Job Market Paper

The Impact of Fiscal Policies to Promote Healthy Diets on Birth Outcomes: Evidence from the Navajo Nation
(with Cawley, J. & Simon, K.)

Abstract In light of widespread increases in diet-related chronic disease, numerous intergovernmental and public health organizations have advocated for fiscal policies to improve diets. One of the most comprehensive such policies in the world was adopted by the Navajo Nation, which has a high prevalence of food insecurity and gestational diabetes. Their Healthy Diné Nation Act (HDNA) of 2014-15 consists of two parts: 1) an exemption from sales tax for healthy foods and beverages; and 2) a tax increase on unhealthy foods and beverages. This study estimates the impact of the HDNA on birth outcomes. We examine CDC birth certificate data for the U.S. for 2010-2018; i.e. for more than 4 years before to 3 years after the HDNA. We estimate difference-in-difference models and event studies that estimate the effect of the HDNA on a variety of outcomes concerning the health of newborns (e.g. birth weight, premature births) and mothers (e.g. pre-pregnancy weight, weight gain during pregnancy, and gestational diabetes). The treatment group consists of mothers whose self-reported race is American Indian and Alaskan Native (AIAN) and who live in the counties of the Navajo Nation. The comparison group consists of mothers whose self-reported race is also AIAN but who live in a county with a reservation or tribal land but outside the three states that include the Navajo Nation (AZ, NM, UT). We hypothesize that the HDNA, given that it was designed to promote healthy diets, improved health outcomes for newborns and mothers. In general, however, the HDNA had no detectable impacts on these outcomes. The comprehensive nature of the HDNA, as well as the prevalence of diet-related chronic disease and maternal and infant health conditions among the Navajo Nation population, make this an important contribution to the evidence base.

Publications

  • Wing, C., & Dreyer, M. (2024). Making Sense of the Difference-in-Difference Design. JAMA Internal Medicine.

  • Dreyer, M., Shukla, A., Sabadee, J., Bibireddy, M., Börner, K., Thyvalikakath, T., & Simon, K. (2023). Opioid Prescriptions Prior to Emergency Department Dental Visits: A Comparison of Dental Health Professional Shortage Areas (DPSAs) and Non-DPSAs Using Electronic Health Records. INQUIRY: The Journal of Health Care Organization, Provision, and Financing.

Working Papers

  • Dreyer, M., McGuire, C., Silva, J., Simon, K., Wing, C., & Ziedan, E. Racial Disparities in Infant Drug Testing. Revise and resubmit at Demography.

  • Choi, J., Dreyer, M., Shone, H., Siegal, N., Simon, K. & Wing, C. Contraception Responses to Abortion Bans.

Conference & Seminar Presentations

  • 2025: 14th Workshop on the Economics of Risky Behaviors, ASHEcon, APPAM (scheduled)
  • 2024: APPAM
  • 2023: ASHEcon