Objective numeracy exacerbates framing effects from decision-making under political risk.

While Prospect Theory helps to explain decision-making under risk, studies often base frames on hypothetical events and fail to acknowledge that many individuals lack the ability and motivation to engage in complex thinking. We use an original survey of US adults (N = 2813) to test Prospect Theory in the context of the May 2023 debt ceiling negotiations in the US Congress and assess whether objective numeracy moderates framing effects. We hypothesize and find evidence to suggest that most respondents are risk-averse to potential gains and risk-accepting to potential losses; however, high numerates are more risk-averse and risk-accepting to gains and losses, respectively, than low numerates. We also find that need for cognition interacts with numeracy to moderate framing effects for prospective losses, such that higher need for cognition attenuates risk-acceptance among low numerates and exacerbates risk-acceptance among high numerates. Our results are robust to a range of other covariates and in models accounting for the interaction between political knowledge and need for cognition, indicating joint moderating effects from two knowledge domains similarly conditioned by the desire to engage in effortful thinking. Our findings demonstrate that those who can understand and use objective information may remain subjectively persuaded by certain policy frames.

What Goes Down Must Come Up? Pandemic- Related Misinformation Search Behavior During an Unplanned Facebook Outage.

Pundits and scholars alike suspect that Facebook plays a role in not only exposing Americans to misinformation, but also encouraging them to seek out misinformation from other sources. Whether or not Facebook is responsible for stimulating misinformation search beyond the social networking site, however, is an open question. If Facebook encourages misinformation search behavior, we might expect search volume on other websites to simultaneously decrease when web traffic to Facebook is comparatively low. Here, we exploit a naturally-occurring and exogenous interruption to Facebook's service to study the site's impact on misinformation search. Difference-in-difference analyses reveal that minute-by-minute Google searches for pandemic misinformation (e.g., unproven COVID-19 remedies, vaccine conspiracy theories) tended to increase during the outage period, in comparison to a typical day (and vs. a placebo). These findings are less consistent with views that the site stimulates misinformation search, and more consistent with a steady and transferable demand for health misinformation. Our results showcase the importance of examining not only the supply side of misinformation, but also the demand side.

Sick as a dog? The prevalence, politicization, and health policy consequences of canine vaccine hesitancy (CVH).

Canine vaccine hesitancy (CVH) can be thought about as dog owners' skepticism about the safety and efficacy of administering routine vaccinations to their dogs. CVH is problematic not only because it may inspire vaccine refusal - which may in turn facilitate infectious disease spread in both canine and human populations - but because it may contribute to veterinary care provider mental/physical health risks. In a nationally representative survey of US adults (N = 2200), we introduce a novel survey-based instrument for measuring CVH. We document pervasive CVH in dog owner subpopulations. Troublingly, we find that CVH is associated with rabies non-vaccination, as well as opposition to evidence-based vaccine policies. We conclude by discussing the human and animal health consequences of CVH, and outline a research agenda for future opinion-based research on this important topic.

Religious affiliation and philosophical and moral beliefs about vaccines: A longitudinal study.

How do religious affiliation and beliefs shape vaccine attitudes and behaviors? This study examined the associations of attitudes and behaviors relevant to the flu, measles-mumps-rubella (MMR), and human-papillomavirus (HPV) vaccines with religious affiliations, as well as philosophical, spiritual, and moral beliefs. Respondents were 3005 adults from a probability-based, four-wave panel survey in the United States. Longitudinal structural equation modeling examined how religious affiliations and philosophical/moral beliefs shaped attitudes toward vaccines and actual vaccination. Stronger philosophical beliefs predicted more negative attitudes toward each vaccine and stronger moral beliefs more negative attitudes toward the HPV vaccine. Negative vaccine attitudes then predicted weaker intentions to encourage others to vaccinate and lower probability of receiving a vaccine. Theoretical and public health messaging implications are discussed.

Quantifying the effect of Wakefield et al. (1998) on skepticism about MMR vaccine safety in the U.S.

BACKGROUND: Efforts to trace the rise of childhood vaccine safety concerns in the US often suggest Andrew Wakefield and colleagues' retracted 1998 Lancet study (AW98)-which alleged that the MMR vaccine can cause children to develop autism-as a primary cause of US vaccine skepticism. However, a lack of public opinion data on MMR safety collected before/after AW98's publication obscures whether anecdotal accounts are indicative of a potentially-causal effect. METHODS: We address this problem using a regression discontinuity framework to study change in monthly MMR injury claims (N = 74,850; from 1990-2019) from the Vaccine Adverse Events Reporting System (VAERS) to proxy concern about vaccine safety. Additionally, we suggest a potential mechanism for the effect of AW98 on vaccine skepticism, via automated sentiment analyses of MMR-related news stories (N = 674; from 1996-2000) in major television and newspaper outlets. RESULTS: AW98 led to an immediate increase of about 70 MMR injury claims cases per month, averaging across six estimation strategies (meta-analytic effect = 70.44 [52.19, 88.75], p < 0.01). Preliminary evidence suggests that the volume of negative media attention to MMR increased in the weeks following AW98's publication, across four estimation strategies (meta-analytic effect = 9.59% [3.66, 15.51], p < 0.01). CONCLUSIONS: Vaccine skepticism increased following the publication of AW98, which was potentially made possible by increased negative media coverage of MMR. SIGNIFICANCE: Childhood vaccine skepticism presents an important challenge to widespread vaccine uptake, and undermines support for pro-vaccine health policies. In addition to advancing our understanding of the previously-obscured origins of US vaccine skepticism, our work cautions that high-profile media attention to inaccurate scientific studies can undermine public confidence in vaccines. We conclude by offering several recommendations that researchers and health communicators might consider to detect and address future threats to vaccine confidence.

The effects of scientific messages and narratives about vaccination.

A fundamental challenge complicates news decisions about covering vaccine side effects: although serious vaccine side effects are rare, less severe ones do occur occasionally. The study was designed to test whether a side effect message could induce vaccine hesitancy and whether that could be countered by pro-vaccine messages about vaccine safety. A large (N = 2,345), nationally representative experiment was conducted by randomly exposing participants to one of six videos about the measles, mumps, and rubella (MMR) vaccine edited from news programs produced during the 2019 measles outbreak in the United States. The design was a 2x3 factorial crossing the presence or absence of a hesitancy-inducing narrative message with a pro-vaccine science-supporting message (i.e., no message, science-supporting expert message, or pro-vaccine narrative message), leading to a total of six conditions. A general linear model was used to assess the effects of these videos on respondents' (1) vaccine risk perceptions, (2) policy views on vaccination, (3) willingness to encourage others to vaccinate their children, and (4) intention to send a pro-vaccine letter to their state representative. Findings indicated that the science-supporting expert message about vaccine safety led to higher pro-vaccine evaluations relative to other conditions [e.g., b = -0.17, p < .001, a reduction in vaccine risk perceptions of 0.17 as compared to the control]. There was also suggestive evidence that the hesitancy-inducing narrative may limit the effectiveness of a science-supporting expert message, although this finding was not consistent across different outcomes. When shown alone the hesitancy-inducing narrative did not shift views and intentions, but more research is needed to ascertain whether exposure to such messages can undercut the pro-vaccine influence of science-supporting (expert) ones. All in all, however, it is clear that science-supporting messages are effective and therefore worthwhile in combating vaccine misinformation.

Policy Views and Negative Beliefs About Vaccines in the United States, 2019.

Objectives. To determine whether holding vaccine misconceptions, in the form of negative beliefs about vaccines, correlates with opposing governmental action at all levels designed to increase vaccination (e.g., removing personal belief and religious vaccine exemptions).Methods. Drawing on data from a nationally representative survey of 1938 US adults, we assessed the relation between negative beliefs about vaccines and provaccination policies.Results. Beyond sociodemographic and policy-relevant variables, such as gender and partisan affiliation, questionable negative beliefs about vaccines are the strongest predictor of opposition to policies designed to increase vaccination.Conclusions. Negative beliefs about vaccines in the general population may thwart the passage or implementation of policies designed to increase vaccination. Implementing strategies that reduce these negative beliefs should be a priority of educators and public health officials.