Milkman et al.

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-mo 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 d 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.

No abstract

Honest reporting is essential for society to function well. However, people frequently lie when asked to provide information, such as misrepresenting their income to save money on taxes. A landmark finding published in PNAS [L. L. (2012)] provided evidence for a simple way of encouraging honest reporting: asking people to sign a veracity statement at the beginning instead of at the end of a self-report form. Since this finding was published, various government agencies have adopted this practice. However, in this project, we failed to replicate this result. Across five conceptual replications (n = 4,559) and one highly powered, preregistered, direct replication (n = 1,235) conducted with the authors of the original paper, we observed no effect of signing first on honest reporting. Given the policy applications of this result, it is important to update the scientific record regarding the veracity of these results.nudge | policy-making | morality | replication F ive of the seven authors of this manuscript conducted research published in PNAS (1), showing that signing a veracity statement at the beginning of a tax form (in two small-sample laboratory studies) as well as an insurance audit form (in a field experiment), as opposed to the standard procedure of signing it at the end of the form, decreases dishonest reporting of personal information. The original paper also found that signing first reduces dishonesty by making ethics more salient, although this effect was demonstrated only in one small-sample laboratory experiment. Three of the authors (Kristal, Whillans, and Bazerman) attempted to extend what we thought was the critical finding from that PNAS paper: simply signing a veracity statement at the beginning instead of at the end of a task in which individuals can cheat and report a higher performance to earn more money reduces dishonest reporting. In particular, Kristal, Whillans, and Bazerman initiated a new project on inducing honesty online by signing first versus last. However, despite repeated attempts, Kristal, Whillans, and Bazerman did not find that signing a veracity statement at the beginning of a task reduced dishonesty in comparison to signing at the end. As a consequence of these null effects, together with the original authors of the PNAS paper, the authors then set out to conduct a direct replication of the first laboratory experiment described in the PNAS paper (1).There are several reasons why Kristal, Whillans, and Bazerman continued to pursue this line of research and why we eventually conducted a direct replication. The original finding has been cited 345 times in peer-reviewed publications, and governments around the world have spent time and effort operationalizing this finding in various policy domains. We are also aware of two published failures of signing first to increase tax collection. The most relevant is an experiment that was conducted in a local authority in the United Kingdom (2). In this experiment, the intervention directly tested the veracity statement and signature require...