Personal risk or societal benefit? Investigating adults' support for COVID-19 childhood vaccination.

Parental hesitancy poses a serious threat to the success of the COVID-19 childhood vaccination campaign. We investigate whether adults' opinions on childhood vaccination can be influenced via two survey experiments in Italy (n = 3,633 participants) and the UK (n = 3,314 participants). Respondents were randomly assigned to: a "risk treatment" that highlighted the potential risks of COVID-19 to a child, a "herd immunity treatment" that emphasized the community benefits of pediatric vaccination, or a control message. Participants' probability of supporting COVID-19 childhood vaccination was then assessed on a 0-100 scale. We find that the "risk treatment" reduced the proportion of Italian parents strongly against vaccination by up to 29.6 %, while increasing the proportion of neutral parents by up to 45.0 %. The "herd immunity treatment", instead, was only effective among non-parents, resulting in a lower proportion of individuals against pediatric vaccination and a higher proportion of individuals in favor (both shifted by around 20 %).

Testing persuasive messaging to encourage COVID-19 risk reduction.

What types of public health messages are effective at changing people's beliefs and intentions to practice social distancing to slow the spread of COVID-19? We conducted two randomized experiments in summer 2020 that assigned respondents to read a public health message and then measured their beliefs and behavioral intentions across a wide variety of outcomes. Using both a convenience sample and a pre-registered replication with a nationally representative sample of Americans, we find that a message that reframes not social distancing as recklessness rather than bravery and a message that highlights the need for everyone to take action to protect one another are the most effective at increasing beliefs and intentions related to social distancing. These results provide an evidentiary basis for building effective public health campaigns to increase social distancing during flu pandemics.

Identifying legitimacy: Experimental evidence on compliance with authority.

To what extent do individuals' perceptions of legitimacy affect their intrinsic motivations to comply with an authority? Answering this question has critical implications for law enforcement but is challenging because actions or institutions that affect intrinsic motivations typically also affect extrinsic, material ones. To disentangle these, we propose an experimental approach that separately identifies the effect of an authority's costly action to improve enforcement fairness on citizen behavior through both intrinsic and extrinsic channels. In experiment 1, the authority's simple attempt to institute fairer enforcement increases prosocial behavior by 10 to 12 percentage points via the intrinsic channel. A follow-up experiment demonstrates that this is not motivated by citizen attempts to "pay back" authorities. Our findings provide causally credible evidence that an authority's actions can directly shape citizens' behavior by enhancing her legitimacy and have important implications in policy domains where this conflicts with other incentives.

Persuading US White evangelicals to vaccinate for COVID-19: Testing message effectiveness in fall 2020 and spring 2021.

The development of COVID-19 vaccines was an important breakthrough for ending the pandemic. However, people refusing to get vaccinated diminish the level of community protection afforded to others. In the United States, White evangelicals have proven to be a particularly difficult group to convince to get vaccinated. Here we investigate whether this group can be persuaded to get vaccinated. To do this, we leverage data from two survey experiments, one fielded prior to approval of COVID-19 vaccines (study 1) and one fielded after approval (study 2). In both experiments, respondents were randomly assigned to treatment messages to promote COVID-19 vaccination. In study 1, we find that a message that emphasizes community interest and reciprocity with an invocation of embarrassment for choosing not to vaccinate is the most effective at increasing uptake intentions, while values-consistent messaging appears to be ineffective. In contrast, in study 2 we observe that this message is no longer effective and that most messages produce little change in vaccine intent. This inconsistency may be explained by the characteristics of White evangelicals who remain unvaccinated vis à vis those who got vaccinated. These results demonstrate the importance of retesting messages over time, the apparent limitations of values-targeted messaging, and document the need to consider heterogeneity even within well-defined populations. This work also cautions against drawing broad conclusions from studies carried out at a single point in time during the COVID-19 pandemic.

Persuasive messaging to increase COVID-19 vaccine uptake intentions.

Widespread vaccination remains the best option for controlling the spread of COVID-19 and ending the pandemic. Despite the considerable disruption the virus has caused to people's lives, many people are still hesitant to receive a vaccine. Without high rates of uptake, however, the pandemic is likely to be prolonged. Here we use two survey experiments to study how persuasive messaging affects COVID-19 vaccine uptake intentions. In the first experiment, we test a large number of treatment messages. One subgroup of messages draws on the idea that mass vaccination is a collective action problem and highlighting the prosocial benefit of vaccination or the reputational costs that one might incur if one chooses not to vaccinate. Another subgroup of messages built on contemporary concerns about the pandemic, like issues of restricting personal freedom or economic security. We find that persuasive messaging that invokes prosocial vaccination and social image concerns is effective at increasing intended uptake and also the willingness to persuade others and judgments of non-vaccinators. We replicate this result on a nationally representative sample of Americans and observe that prosocial messaging is robust across subgroups, including those who are most hesitant about vaccines generally. The experiments demonstrate how persuasive messaging can induce individuals to be more likely to vaccinate and also create spillover effects to persuade others to do so as well. The first experiment in this study was registered at clinicaltrials.gov and can be found under the ID number NCT04460703. This study was registered at Open Science Framework (OSF) at: https://osf.io/qu8nb/?view_only=82f06ecad77f4e54b02e8581a65047d7.

Experimental evidence that changing beliefs about mask efficacy and social norms increase mask wearing for COVID-19 risk reduction: Results from the United States and Italy.

In the absence of widespread vaccination for COVID-19, governments and public health officials have advocated for the public to wear masks during the pandemic. The decision to wear a mask in public is likely affected by both beliefs about its efficacy and the prevalence of the behavior. Greater mask use in the community may encourage others to follow this norm, but it also creates an incentive for individuals to free ride on the protection afforded to them by others. We report the results of two vignette-based experiments conducted in the United States (n = 3,100) and Italy (n = 2,659) to examine the causal relationship between beliefs, social norms, and reported intentions to engage in mask promoting behavior. In both countries, survey respondents were quota sampled to be representative of the country's population on key demographics. We find that providing information about how masks protect others increases the likelihood that someone would wear a mask or encourage others to do so in the United States, but not in Italy. There is no effect of providing information about how masks protect the wearer in either country. Additionally, greater mask use increases intentions to wear a mask and encourage someone else to wear theirs properly in both the United States and Italy. Thus, community mask use may be self-reinforcing.

National interest may require distributing COVID-19 vaccines to other countries.

As immunization campaigns are accelerating, understanding how to distribute the scarce doses of vaccines is of paramount importance and a quantitative analysis of the trade-offs involved in domestic-only versus cooperative distribution is still missing. In this study we use a network Susceptible-Infected-Removed (SIR) model to show circumstances under which it is in a country's self-interest to ensure other countries can obtain COVID-19 vaccines rather than focusing only on vaccination of their own residents. In particular, we focus our analysis on the United States and estimate the internal burden of COVID-19 disease under different scenarios about vaccine cooperation. We show that in scenarios in which the US has reached the threshold for domestic herd immunity, the US may find it optimal to donate doses to other countries with lower vaccination coverage, as this would allow for a sharp reduction in the inflow of infected individuals from abroad.

Not by turnout alone: Measuring the sources of electoral change, 2012 to 2016.

Changes in partisan outcomes between consecutive elections must come from changes in the composition of the electorate or changes in the vote choices of consistent voters. How much composition versus conversion drives electoral change has critical implications for the policy mandates of election victories and campaigning and governing strategies. Here, we analyze electoral change between the 2012 and 2016 U.S. presidential elections using administrative data. We merge precinct-level election returns, the smallest geography at which vote counts are available, with individual-level turnout records from 37 million registered voters in six key states. We find that both factors were substantively meaningful drivers of electoral change, but the balance varied by state. We estimate that pro-Republican Party (GOP) conversion among two-election voters was particularly important in states including Ohio, Michigan, and Pennsylvania where the pro-GOP swings were largest. Our results suggest conversion remains a crucial component of electoral change.

The racial burden of voter list maintenance errors: Evidence from Wisconsin's supplemental movers poll books.

Administrative records are increasingly used to identify registered voters who may have moved, with potential movers then sent postcards asking them to confirm their address of registration. It is important to understand how often these registrants did not move, and how often such an error is not corrected by the postcard confirmation process, because uncorrected errors make it more difficult for a registrant to subsequently vote. While federal privacy protections generally prevent researchers from observing the data necessary to estimate these quantities, we are able to study this process in Wisconsin because special poll books, available via public records requests, listed those registrants who were identified as potential movers and did not respond to a subsequent postcard. At least 4% of these registrants cast a ballot at their address of registration, with minority registrants twice as likely as white registrants to do so.

Timing of COVID-19 vaccine approval and endorsement by public figures.

The global spread of COVID-19 has created an urgent need for a safe and effective vaccine. However, in the United States, the politicization of the vaccine approval process, including which public figures are endorsing it, could undermine beliefs about its safety and efficacy and willingness to receive it. Using a pair of randomized survey experiments, we show that announcing approval of a COVID-19 vaccine one week before the presidential election compared to one week after considerably reduces both beliefs about its safety and efficacy and intended uptake. However, endorsement by Dr. Anthony Fauci increases confidence and uptake among all partisan subgroups. Further, an endorsement by Dr. Fauci increased uptake and confidence in safety even if a vaccine receives pre-election approval. The results here suggest that perceptions of political influence in COVID-19 vaccine approval could significantly undermine the viability of a vaccine as a strategy to end the pandemic.

Local demographic changes and US presidential voting, 2012 to 2016.

Immigration and demographic change have become highly salient in American politics, partly because of the 2016 campaign of Donald Trump. Previous research indicates that local influxes of immigrants or unfamiliar ethnic groups can generate threatened responses, but has either focused on nonelectoral outcomes or analyzed elections in large geographic units, such as counties. Here, we examine whether demographic changes at low levels of aggregation were associated with vote shifts toward an anti-immigration presidential candidate between 2012 and 2016. To do so, we compile a precinct-level dataset of election results and demographic measures for almost 32,000 precincts in the states of Florida, Georgia, Michigan, Nevada, Ohio, Pennsylvania, and Washington. We employ regression analyses varying model specifications and measures of demographic change. Our estimates uncover little evidence that influxes of Hispanics or noncitizen immigrants benefited Trump relative to past Republicans, instead consistently showing that such changes were associated with shifts to Trump's opponent.

The voting experience and beliefs about ballot secrecy.

New democracies go to great lengths to implement institutional protections of the electoral process. However, in this paper we present evidence that shows that even in the United States-where the secret ballot has been in place for generations-doubts about the secrecy of the voting process are surprisingly prevalent. Many say that their cast ballot can be matched to their name or that others could observe their vote choices while they were voting. We find that people who have not previously voted are particularly likely to harbor doubts about the secrecy of voters' ballots. Those who vote by mail in the privacy of their own homes also feel that others are able to discover their vote choices. Taken together, these findings suggest an important divergence between public perceptions about and the institutional status of the secret ballot in the United States, a divergence that may affect patterns of voting behavior and political participation.

The effect on turnout of campaign mobilization messages addressing ballot secrecy concerns: A replication experiment.

Given the persistence of public doubts about the integrity of ballot secrecy, which depress turnout, two prior experiments have shown precise evidence that both official governmental and unofficial mobilization campaigns providing assurances about ballot secrecy increase turnout among recently registered nonvoters. To assess whether these findings replicate in other political settings, we describe a replication experiment where a non-governmental, non-partisan mobilization campaign sent similar treatment mailings containing assurances about ballot secrecy protections to recently registered nonvoters during the 2014 general election in Mississippi. We find that sending this mailer has no effect on turnout rates in this setting, which is characterized by an unusually low baseline turnout rate. These results are consistent with past research concluding that nonpartisan Get Out The Vote (GOTV) mail has very weak effects among very low turnout propensity registrants, and suggest that there are heterogeneous effects of ballot secrecy treatments associated with subjects' characteristics and the electoral context.

A field experiment shows that subtle linguistic cues might not affect voter behavior.

One of the most important recent developments in social psychology is the discovery of minor interventions that have large and enduring effects on behavior. A leading example of this class of results is in the work by Bryan et al. [Bryan CJ, Walton GM, Rogers T, Dweck CS (2011) Proc Natl Acad Sci USA 108(31):12653-12656], which shows that administering a set of survey items worded so that subjects think of themselves as voters (noun treatment) rather than as voting (verb treatment) substantially increases political participation (voter turnout) among subjects. We revisit these experiments by replicating and extending their research design in a large-scale field experiment. In contrast to the 11 to 14% point greater turnout among those exposed to the noun rather than the verb treatment reported in the work by Bryan et al., we find no statistically significant difference in turnout between the noun and verb treatments (the point estimate of the difference is approximately zero). Furthermore, when we benchmark these treatments against a standard get out the vote message, we estimate that both are less effective at increasing turnout than a much shorter basic mobilization message. In our conclusion, we detail how our study differs from the work by Bryan et al. and discuss how our results might be interpreted.