A Randomized Trial of Behavioral Nudges Delivered Through Text Messages to Increase Influenza Vaccination Among Patients With an Upcoming Primary Care Visit.

PURPOSE: To evaluate if nudges delivered by text message prior to an upcoming primary care visit can increase influenza vaccination rates. DESIGN: Randomized, controlled trial. SETTING: Two health systems in the Northeastern US between September 2020 and March 2021. SUBJECTS: 74,811 adults. INTERVENTIONS: Patients in the 19 intervention arms received 1-2 text messages in the 3 days preceding their appointment that varied in their format, interactivity, and content. MEASURES: Influenza vaccination. ANALYSIS: Intention-to-treat. RESULTS: Participants had a mean (SD) age of 50.7 (16.2) years; 55.8% (41,771) were female, 70.6% (52,826) were White, and 19.0% (14,222) were Black. Among the interventions, 5 of 19 (26.3%) had a significantly greater vaccination rate than control. On average, the 19 interventions increased vaccination relative to control by 1.8 percentage points or 6.1% (P = .005). The top performing text message described the vaccine to the patient as "reserved for you" and led to a 3.1 percentage point increase (95% CI, 1.3 to 4.9; P < .001) in vaccination relative to control. Three of the top five performing messages described the vaccine as "reserved for you." None of the interventions performed worse than control. CONCLUSIONS: Text messages encouraging vaccination and delivered prior to an upcoming appointment significantly increased influenza vaccination rates and could be a scalable approach to increase vaccination more broadly.

Megastudies improve the impact of applied behavioural science.

Policy-makers are increasingly turning to behavioural science for insights about how to improve citizens' decisions and outcomes1. Typically, different scientists test different intervention ideas in different samples using different outcomes over different time intervals2. The lack of comparability of such individual investigations limits their potential to inform policy. Here, to address this limitation and accelerate the pace of discovery, we introduce the megastudy-a massive field experiment in which the effects of many different interventions are compared in the same population on the same objectively measured outcome for the same duration. In a megastudy targeting physical exercise among 61,293 members of an American fitness chain, 30 scientists from 15 different US universities worked in small independent teams to design a total of 54 different four-week digital programmes (or interventions) encouraging exercise. We show that 45% of these interventions significantly increased weekly gym visits by 9% to 27%; the top-performing intervention offered microrewards for returning to the gym after a missed workout. Only 8% of interventions induced behaviour change that was significant and measurable after the four-week intervention. Conditioning on the 45% of interventions that increased exercise during the intervention, we detected carry-over effects that were proportionally similar to those measured in previous research3-6. Forecasts by impartial judges failed to predict which interventions would be most effective, underscoring the value of testing many ideas at once and, therefore, the potential for megastudies to improve the evidentiary value of behavioural science.

Using Fresh Starts to Nudge Increased Retirement Savings.

We conducted a field experiment to study the effect of framing future moments in time as new beginnings (or "fresh starts"). University employees (N=6,082) received mailings with an opportunity to choose between increasing their contributions to a savings plan immediately or at a specified future time point. Framing the future time point in relation to a fresh start date (e.g., the recipient's birthday, the first day of spring) increased the likelihood that the mailing recipient chose to increase contributions at that future time point without decreasing their likelihood of increasing contributions immediately. Overall, fresh start framing increased retirement plan contributions in the eight months following the mailing. Our findings represent the first experimental demonstration of the benefits of fresh start framing in a consequential field setting.

Active choice, implicit defaults, and the incentive to choose.

Home-delivered prescriptions have no delivery charge and lower copayments than prescriptions picked up at a pharmacy. Nevertheless, when home delivery is offered on an opt-in basis, the take-up rate is only 6%. We study a program that makes active choice of either home delivery or pharmacy pick-up a requirement for insurance eligibility. The program introduces an implicit default for those who don't make an active choice: pharmacy pick-up without insurance subsidies. Under this program, 42% of eligible employees actively choose home delivery, 39% actively choose pharmacy pick-up, and 19% make no active choice and are assigned the implicit default. Individuals who financially benefit most from home delivery are more likely to choose it. Those who benefit least from insurance subsidies are more likely to make no active choice and lose those subsidies. The implicit default incentivizes people to make an active choice, thereby playing a key role in choice architecture.

A megastudy of text-based nudges encouraging patients to get vaccinated at an upcoming doctor's appointment.

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 boost adoption of the influenza vaccine. Our findings suggest that text messages sent prior to a primary care visit can boost vaccination rates by an average of 5%. Overall, interventions performed better when they were 1) framed as reminders to get flu shots that were already reserved for the patient and 2) congruent with the sort of communications patients expected to receive from their healthcare provider (i.e., not surprising, casual, or interactive). The best-performing intervention in our study reminded patients twice to get their flu shot at their upcoming doctor's appointment and indicated it was reserved for them. This successful script could be used as a template for campaigns to encourage the adoption of life-saving vaccines, including against COVID-19.

Creating Exercise Habits Using Incentives: The Tradeoff between Flexibility and Routinization.

Habits involve regular, cue-triggered routines. In a field experiment, we tested whether incentivizing exercise routines-paying participants each time they visit the gym within a planned, daily two-hour window-leads to more persistent exercise than offering flexible incentives-paying participants each day they visit the gym, regardless of timing. Routine incentives generated fewer gym visits than flexible incentives, both during our intervention and after incentives were removed. Even among sub-groups that were experimentally induced to exercise at similar rates during our intervention, recipients of routine incentives exhibited a larger decrease in exercise after the intervention than recipients of flexible incentives.

Do physician incentives increase patient medication adherence?

OBJECTIVE: To test the effectiveness of physician incentives for increasing patient medication adherence in three drug classes: diabetes medication, antihypertensives, and statins. DATA SOURCES: Pharmacy and medical claims from a large Medicare Advantage Prescription Drug Plan from January 2011 to December 2012. STUDY DESIGN: We conducted a randomized experiment (911 primary care practices and 8,935 nonadherent patients) to test the effect of paying physicians for increasing patient medication adherence in three drug classes: diabetes medication, antihypertensives, and statins. We measured patients' medication adherence for 18 (6) months before (after) the intervention. DATA COLLECTION/EXTRACTION METHODS: We obtained data directly from the health insurer. PRINCIPAL FINDINGS: We found no evidence that physician incentives increased adherence in any drug class. Our results rule out increases in the proportion of days covered by medication larger than 4.2 percentage points. CONCLUSIONS: Physician incentives of $50 per patient per drug class are not effective for increasing patient medication adherence among the drug classes and primary care practices studied. Such incentives may be more likely to improve measures under physicians' direct control rather than those that predominantly reflect patient behaviors. Additional research is warranted to disentangle whether physician effort is not responsive to these types of incentives, or medication adherence is not responsive to physician effort. Our results suggest that significant changes in the incentive amount or program design may be necessary to produce responses from physicians or patients.

Which Early Withdrawal Penalty Attracts the Most Deposits to a Commitment Savings Account?

Previous research has shown that some people voluntarily use commitment contracts that restrict their own choice sets. We study how people divide money between two accounts: a liquid account that permits unrestricted withdrawals and a commitment account that is randomly assigned in a between-subject design to have either a 10% early withdrawal penalty, or a 20% early withdrawal penalty, or not to allow early withdrawals at all (i.e., an infinite penalty). When the liquid account and the commitment account pay the same interest rate, higher early-withdrawal penalties attract more commitment account deposits. This pattern is predicted by the hypothesis that some participants are partially- or fully-sophisticated present-biased agents. Such agents perceive that higher penalties generate greater scope for commitment by disincentivizing (penalized) early withdrawals. The experiment also shows that when the commitment account pays a higher interest rate than the liquid account, the positive empirical slope relating penalties and commitment deposits is flattened, suggesting that naïve present-biased agents or agents with standard exponential discounting are also in our sample. Across all of our experimental treatments, higher early withdrawal penalties on the commitment account sometimes increase and never reduce allocations to the commitment account.

Nudging: Progress to date and future directions.

Nudges influence behavior by changing the environment in which decisions are made, without restricting the menu of options and without altering financial incentives. This paper assesses past empirical research on nudging and provides recommendations for future work in this area by discussing examples of successful and unsuccessful nudges and by analyzing 174 articles that estimate nudge treatment effects. Researchers in disciplines spanning the behavioral sciences, using varied data sources, have documented that many different types of nudges succeed in changing behavior in a wide range of domains. Nudges that automate some aspect of the decision-making process have an average effect size, measured by Cohen's d, that is 0.193 larger than that of other nudges. Our analyses point to the need for future research to pay greater attention to (1) determining which types of nudges tend to be most impactful; (2) using field and laboratory research approaches as complementary methods; (3) measuring long-run effects of nudges; (4) considering effects of nudges on non-targeted outcomes; and (5) examining interaction effects among nudges and other interventions.

Does front-loading taxation increase savings? Evidence from Roth 401(k) introductions.

Can governments increase private savings by taxing savings up front instead of in retirement? Roth 401(k) contributions are not tax-deductible in the contribution year, but withdrawals in retirement are untaxed. The more common before-tax 401(k) contribution is tax-deductible in the contribution year, but both principal and investment earnings are taxed upon withdrawal. Using administrative data from eleven companies that added a Roth contribution option to their existing 401(k) plan between 2006 and 2010, we find no evidence that total 401(k) contribution rates differ between employees hired before versus after Roth introduction, which implies that take-home pay declines and the amount of retirement consumption being purchased by 401(k) contributions increases after Roth introduction. We reject several neoclassical explanations for our null finding. Results from a survey experiment suggest two behavioral explanations: (1) employee confusion about and neglect of the tax properties of Roth balances and (2) partition dependence.

Should Governments Invest More in Nudging?

Governments are increasingly adopting behavioral science techniques for changing individual behavior in pursuit of policy objectives. The types of "nudge" interventions that governments are now adopting alter people's decisions without coercion or significant changes to economic incentives. We calculated ratios of impact to cost for nudge interventions and for traditional policy tools, such as tax incentives and other financial inducements, and we found that nudge interventions often compare favorably with traditional interventions. We conclude that nudging is a valuable approach that should be used more often in conjunction with traditional policies, but more calculations are needed to determine the relative effectiveness of nudging.

A commitment contract to achieve virologic suppression in poorly adherent patients with HIV/AIDS.

OBJECTIVE: Assess whether a commitment contract informed by behavioral economics leads to persistent virologic suppression among HIV-positive patients with poor antiretroviral therapy (ART) adherence. DESIGN: Single-center pilot randomized clinical trial and a nonrandomized control group. SETTING: Publicly funded HIV clinic in Atlanta, Georgia, USA. INTERVENTION: The study involved three arms. First, participants in the provider visit incentive (PVI) arm received $30 after attending each scheduled provider visit. Second, participants in the incentive choice arm were given a choice between the above arrangement and a commitment contract that made the $30 payment conditional on both attending the provider visit and meeting an ART adherence threshold. Third, the passive control arm received routine care and no incentives. PARTICIPANTS: A total of 110 HIV-infected adults with a recent plasma HIV-1 viral load more than 200 copies/ml despite ART. The sample sizes of the three groups were as follows: PVI, n = 21; incentive choice, n = 19; and passive control, n = 70. MAIN OUTCOME MEASURE: Virologic suppression (plasma HIV-1 viral load ≤200 copies/ml) at the end of the incentive period and at an unanticipated postincentive study visit approximately 3 months later. RESULTS: The odds of suppression were higher in the incentive choice arm than in the passive control arm at the postincentive visit (adjusted odds ratio 3.93, 95% confidence interval 1.19-13.04, P = 0.025). The differences relative to the passive control arm at the end of the incentive period and relative to the PVI arm at both points in time were not statistically significant. CONCLUSION: Commitment contracts can improve ART adherence and virologic suppression. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01455740.

Does Aggregated Returns Disclosure Increase Portfolio Risk Taking?

Many experiments have found that participants take more investment risk if they see returns less frequently, see portfolio-level returns (rather than each individual asset's returns), or see long-horizon (rather than one-year) historical return distributions. In contrast, we find that such information aggregation treatments do not affect total equity investment when we make the investment environment more realistic than in prior experiments. Previously documented aggregation effects are not robust to changes in the risky asset's return distribution or the introduction of a multi-day delay between portfolio choice and return realizations.

Vaccination Rates are Associated With Functional Proximity But Not Base Proximity of Vaccination Clinics.

BACKGROUND: Routine annual influenza vaccinations are recommended for persons 6 months of age and older, but less than half of US adults get vaccinated. Many employers offer employees free influenza vaccinations at workplace clinics, but even then take-up is low. OBJECTIVE: To determine whether employees are significantly more likely to get vaccinated if they have a higher probability of walking by the clinic for reasons other than vaccination. METHOD: We obtained data from an employer with a free workplace influenza vaccination clinic. Using each employee's building entry/exit swipe card data, we test whether functional proximity-the likelihood that the employee walks by the clinic for reasons other than vaccination-predicts whether the employee gets vaccinated at the clinic. We also test whether base proximity-the inverse of walking distance from the employee's desk to the clinic-predicts vaccination probability. PARTICIPANTS: A total of 1801 employees of a health benefits administrator that held a free workplace influenza vaccination clinic. RESULTS: A 2 SD increase in functional proximity is associated with a 6.4 percentage point increase in the probability of vaccination (total vaccination rate at company=40%), even though the average employee's desk is only 166 meters from the clinic. Base proximity does not predict vaccination probability. CONCLUSIONS AND RELEVANCE: Minor changes in the environment can have substantial effects on the probability of vaccination. If these results generalize, health systems should emphasize functional proximity over base proximity when locating preventive health services.

The Effect of Providing Peer Information on Retirement Savings Decisions.

Using a field experiment in a 401(k) plan, we measure the effect of disseminating information about peer behavior on savings. Low-saving employees received simplified plan enrollment or contribution increase forms. A randomized subset of forms stated the fraction of age-matched coworkers participating in the plan or age-matched participants contributing at least 6% of pay to the plan. We document an oppositional reaction: the presence of peer information decreased the savings of nonparticipants who were ineligible for 401(k) automatic enrollment, and higher observed peer savings rates also decreased savings. Discouragement from upward social comparisons seems to drive this reaction.

What Makes Annuitization More Appealing?

We conduct and analyze two large surveys of hypothetical annuitization choices. We find that allowing individuals to annuitize a fraction of their wealth increases annuitization relative to a situation where annuitization is an "all or nothing" decision. Very few respondents choose declining real payout streams over flat or increasing real payout streams of equivalent expected present value. Highlighting the effects of inflation increases demand for cost of living adjustments. Frames that highlight flexibility, control, and investment significantly reduce annuitization. A majority of respondents prefer to receive an extra "bonus" payment during one month of the year that is funded by slightly lower payments in the remaining months. Concerns about later-life income, spending flexibility, and counterparty risk are the most important self-reported motives that influence the annuitization decision.

Consumers' misunderstanding of health insurance.

We report results from two surveys of representative samples of Americans with private health insurance. The first examines how well Americans understand, and believe they understand, traditional health insurance coverage. The second examines whether those insured under a simplified all-copay insurance plan will be more likely to engage in cost-reducing behaviors relative to those insured under a traditional plan with deductibles and coinsurance, and measures consumer preferences between the two plans. The surveys provide strong evidence that consumers do not understand traditional plans and would better understand a simplified plan, but weaker evidence that a simplified plan would have strong appeal to consumers or change their healthcare choices.

Testimonials do not convert patients from brand to generic medication.

OBJECTIVES: To assess whether the addition of a peer testimonial to an informational mailing increases conversion rates from brand name prescription medications to lower-cost therapeutic equivalents, and whether the testimonial's efficacy increases when information is added about an affiliation the quoted individual shares with the recipient. RESEARCH DESIGN AND METHODS: A total of 5498 union members were randomly assigned to receive 1 of 3 different informational letters: 1 without a testimonial (No Testimonial Group), 1 with a testimonial from a person whose shared union affiliation with the recipient was not disclosed (Unaffiliated Testimonial Group), and 1 with a testimonial from a person whose shared union affiliation with the recipient was disclosed (Affiliated Testimonial Group). RESULTS: The conversion rate for the No Testimonial Group was 12.2%, which is higher than the Unaffiliated Testimonial Group rate of 11.3% and the Affiliated Testimonial Group rate of 11.7%. The differences between the groups are not statistically significant. CONCLUSIONS: Short peer testimonials do not increase the impact of a mailed communication on conversion rates to lower-cost, therapeutically equivalent medications, even when the testimonial is presented as coming from a more socially proximate peer

What Goes Up Must Come Down? Experimental Evidence on Intuitive Forecasting.

Do laboratory subjects correctly perceive the dynamics of a mean-reverting time series? In our experiment, subjects receive historical data and make forecasts at different horizons. The time series process that we use features short-run momentum and long-run partial mean reversion. Half of the subjects see a version of this process in which the momentum and partial mean reversion unfold over 10 periods ('fast'), while the other subjects see a version with dynamics that unfold over 50 periods ('slow'). Typical subjects recognize most of the mean reversion of the fast process and none of the mean reversion of the slow process.