Skip to Main Content
HBS Home
  • About
  • Academic Programs
  • Alumni
  • Faculty & Research
  • Baker Library
  • Giving
  • Harvard Business Review
  • Initiatives
  • News
  • Recruit
  • Map / Directions
Faculty & Research
  • Faculty
  • Research
  • Featured Topics
  • Academic Units
  • …→
  • Harvard Business School→
  • Faculty & Research→
Publications
Publications
  • Article
  • Proceedings of the National Academy of Sciences

A 680,000-Person Megastudy of Nudges to Encourage Vaccination in Pharmacies

By: Katherine L. Milkman, Linnea Gandhi, Mitesh S. Patel, Heather N. Graci, Dena M. Gromet, Hung Ho, Joseph S. Kay, Timothy W. Lee, Jake Rothschild, Jonathan E. Bogard, Ilana Brody, Christopher F. Chabris, Edward Chang, Gretchen B. Chapman, Jennifer E. Dannals, Noah J. Goldstein, Amir Goren, Hal Hershfield, Alex Hirsch, Jillian Hmurovic, Samantha Horn, Dean Karlan, Ariella S. Kristal, Cait Lamberton, Michael N. Meyer, Allison H. Oakes, Maurice E. Schweitzer, Maheen Shermohammed, Jaochim H. Talloen, Caleb Warren, Ashley Whillans, Kuldeep N. Yadav, Julian J. Zlatev, Ron Berman, Chalanda N. Evans, Rahul Ladhania, Jens Ludwig, Nina Mazar, Sendhil Mullainathan, Christopher K. Snider, Jann Spiess, Eli Tsukayama, Lyle Ungar, Christophe Van den Bulte, Kevin G. Volpp and Angela L. Duckworth
  • Format:Electronic
ShareBar

Abstract

Encouraging vaccination is a pressing policy problem. To assess whether text-based reminders can encourage pharmacy vaccination and what kinds of messages work best, we conducted a megastudy. We randomly assigned 689,693 Walmart pharmacy patients to receive one of 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination or to a business-as-usual control condition that received no messages. We found that the reminder texts that we tested increased pharmacy vaccination rates by an average of 2.0 percentage points, or 6.8%, over a 3-month follow-up period. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts delivered 3 days apart and communicated to patients that a vaccine was “waiting for you.” Neither experts nor lay people anticipated that this would be the best-performing treatment, underscoring the value of simultaneously testing many different nudges in a highly powered megastudy.

Keywords

Vaccination; Vaccines; Nudges; Communication Strategy; Communication Technology; Consumer Behavior; Health Care and Treatment

Citation

Milkman, Katherine L., Linnea Gandhi, Mitesh S. Patel, Heather N. Graci, Dena M. Gromet, Hung Ho, Joseph S. Kay, Timothy W. Lee, Jake Rothschild, Jonathan E. Bogard, Ilana Brody, Christopher F. Chabris, Edward Chang, Gretchen B. Chapman, Jennifer E. Dannals, Noah J. Goldstein, Amir Goren, Hal Hershfield, Alex Hirsch, Jillian Hmurovic, Samantha Horn, Dean Karlan, Ariella S. Kristal, Cait Lamberton, Michael N. Meyer, Allison H. Oakes, Maurice E. Schweitzer, Maheen Shermohammed, Jaochim H. Talloen, Caleb Warren, Ashley Whillans, Kuldeep N. Yadav, Julian J. Zlatev, Ron Berman, Chalanda N. Evans, Rahul Ladhania, Jens Ludwig, Nina Mazar, Sendhil Mullainathan, Christopher K. Snider, Jann Spiess, Eli Tsukayama, Lyle Ungar, Christophe Van den Bulte, Kevin G. Volpp, and Angela L. Duckworth. "A 680,000-Person Megastudy of Nudges to Encourage Vaccination in Pharmacies." Proceedings of the National Academy of Sciences 119, no. 6 (February 8, 2022).
  • Find it at Harvard

About The Authors

Edward H. Chang

Negotiation, Organizations & Markets
→More Publications

Ashley V. Whillans

Negotiation, Organizations & Markets
→More Publications

Julian J. Zlatev

Negotiation, Organizations & Markets
→More Publications

More from the Authors

    • April 2023
    • Faculty Research

    Ryan Serhant: Time Management for Repeatable Success (A)

    By: Ashley Whillans and Hawken Lord
    • April 2023
    • Journal of Applied Psychology

    A Field Experiment on Subgoal Framing to Boost Volunteering: The Trade-off Between Goal Granularity and Flexibility

    By: Aneesh Rai, Marissa A. Sharif, Edward H. Chang, Katherine L. Milkman and Angela L. Duckworth
    • March 2023
    • Faculty Research

    Río Curicó Teaching Note: Video Short I

    By: Kathleen L. McGinn and Julian Zlatev
More from the Authors
  • Ryan Serhant: Time Management for Repeatable Success (A) By: Ashley Whillans and Hawken Lord
  • A Field Experiment on Subgoal Framing to Boost Volunteering: The Trade-off Between Goal Granularity and Flexibility By: Aneesh Rai, Marissa A. Sharif, Edward H. Chang, Katherine L. Milkman and Angela L. Duckworth
  • Río Curicó Teaching Note: Video Short I By: Kathleen L. McGinn and Julian Zlatev
ǁ
Campus Map
Harvard Business School
Soldiers Field
Boston, MA 02163
→Map & Directions
→More Contact Information
  • Make a Gift
  • Site Map
  • Jobs
  • Harvard University
  • Trademarks
  • Policies
  • Accessibility
  • Digital Accessibility
Copyright © President & Fellows of Harvard College