We partnered with Walmart to test 22 nudges designed to boost vaccination rates in their pharmacies. Nudges were delivered via text message to over 650,000 Walmart pharmacy patients in the fall of 2020 and encouraged patients to visit Walmart for a flu vaccine. We demonstrate that behaviorally...

Many Americans fail to get life-saving vaccines each year, and the availability of a vaccine for COVID-19 makes the challenge of encouraging vaccination more urgent than ever. We present a large field experiment (N=47,306) testing 19 nudges delivered to patients via text message and designed to...