Common measures of vaccination intention generate substantially different estimates that can reduce predictive validity.

Surveys often estimate vaccination intentions using dichotomous ("Yes"/"No") or trichotomous ("Yes," "Unsure," "No") response options presented in different orders. Do survey results depend on these variations? This controlled experiment randomized participants to dichotomous or trichotomous measures of vaccine intentions (with "Yes" and "No" options presented in different orders). Intentions were measured separately for COVID-19, its booster, and influenza vaccines. Among a sample of U.S. adults (N = 4,764), estimates of vaccine intention varied as much as 37.5 ± 17.4 percentage points as a function of the dichotomous or trichotomous response set. Among participants who had not received the COVID-19 vaccine, the "Unsure" option was more likely to reduce the share of "No" (versus "Yes") responses, whereas among participants who had received the COVID-19 vaccine, the "Unsure" option was more likely to reduce the share of "Yes" (versus "No") responses. The "Unsure" category may increase doubt and decrease reliance on past vaccination behavior when forming intentions. The order of "Yes" and "No" responses had no significant effect. Future research is needed to further evaluate why the effects of including the "Unsure" option vary in direction and magnitude.

Comparative effectiveness of mandates and financial policies targeting COVID-19 vaccine hesitancy: A randomized, controlled survey experiment.

Experts debate whether COVID-19 vaccine mandates or financial incentives will reduce, rather than increase, interest in vaccination. Among 3,698 unvaccinated U.S. residents, we conducted a randomized, controlled survey-embedded experiment to estimate the absolute and relative psychological effects of vaccine policies specifying: mandates by employers or airlines, bars, and restaurants; lotteries for $1 million, $200,000, or $100,000; guaranteed cash for $1000, $200, or $100; and $1,000 as either a tax credit or penalty. Vaccine intention -the study outcome- predicts uptake and provides insight into the psychological mechanism that is most proximal to behavior (i.e., vaccination). Compared to controls, those who learned about the $1,000 cash reward policy were 17.1 (±5.3)% more likely to want vaccination. Employer mandates are more promising than other mandate policies (8.6 [+/- 7.4]% vs. 1.4 [+/- 6.0]%). The full results suggest that neither mandates nor financial incentives are likely to have counterproductive psychological effects. These policies are not mutually exclusive and, if implemented well, they may increase vaccine uptake.

The economic value of genetically engineered mosquitoes as a malaria control strategy depends on local transmission rates.

This paper assesses the economic value of genetically engineered (GE) Anopheles gambiae mosquitoes as a malaria control strategy. We use an epidemiological-economic model of malaria transmission to evaluate this technology for a range of village-level transmission settings. In each setting, we evaluate public health outcomes following introduction of GE mosquitoes relative to a "status quo" baseline scenario. We also assess results both in contrast to-and in combination with-a Mass Drug Administration (MDA) strategy. We find that-in low transmission settings-the present value (PV) public health benefits of GE mosquito release are substantial, both relative to status quo dynamics and MDA. In contrast, in high transmission settings, the release of GE mosquitoes may increase steady-state infection rates. Our results indicate that there are substantial policy complementarities when GE mosquito release is combined with local MDA-the combined control strategy can lead to local eradication.

Paying Americans to take the vaccine-would it help or backfire?

This research investigates the extent to which financial incentives (conditional cash transfers) would induce Americans to opt for vaccination against coronavirus disease of 2019. We performed a randomized survey experiment with a representative sample of 1000 American adults in December 2020. Respondents were asked whether they would opt for vaccination under one of three incentive conditions ($1000, $1500, or $2000 financial incentive) or a no-incentive condition. We find that-without coupled financial incentives-only 58 per cent of survey respondents would elect for vaccination. A coupled financial incentive yields an 8-percentage-point increase in vaccine uptake relative to this baseline. The size of the cash transfer does not dramatically affect uptake rates. However, incentive responses differ dramatically by demographic group. Republicans were less responsive to financial incentives than the general population. For Black and Latino Americans especially, very large financial incentives may be counter-productive.

COVID-19 morbidity and mortality in U.S. meatpacking counties.

In this paper, we investigate the extent to which the presence of a large meatpacking (i.e., beef, pork, and broiler chicken) plant has affected county-level COVID-19 transmission dynamics. We find that-within 150 days after emergence of COVID-19 in a given county-the presence of a large beef packing facility increases per capita infection rates by 110%, relative to comparable counties without meatpacking plants. Large pork and chicken processing facilities increase transmission rates by 160% and 20%, respectively. While the presence of this type of industrial agricultural facility is shown to exacerbate initial disease transmission affecting large numbers of individuals in the community, over time daily case rates converge such that rates observed in meatpacking- and non-meatpacking counties become similar. In aggregate, results suggest that 334 thousand COVID-19 infections are attributable to meatpacking plants in the U.S. with associated mortality and morbidity costs totaling more than $11.2 billion.

Are vaccine lotteries worth the money?

This research evaluates the effects of the twelve statewide vaccine lottery schemes that were announced as of June 7, 2021 on state vaccination rates. We construct a dataset that matches information on the timing and location of these lotteries with daily, county-level data from the U.S. Centers for Disease Control (CDC) on the cumulative number of people who have received at least one dose of an emergency-authorized Covid-19 vaccine. We find that 10 of the 12 statewide lotteries studied (i.e., all but Arkansas and California) generated a positive, statistically significant, and economically meaningful impact on vaccine uptake after thirty days. On average, the cost per marginal vaccination across these programs was approximately $55.

Indemnifying precaution: economic insights for regulation of a highly infectious disease.

Economic insights are powerful for understanding the challenge of managing a highly infectious disease, such as COVID-19, through behavioral precautions including social distancing. One problem is a form of moral hazard, which arises when some individuals face less personal risk of harm or bear greater personal costs of taking precautions. Without legal intervention, some individuals will see socially risky behaviors as personally less costly than socially beneficial behaviors, a balance that makes those beneficial behaviors unsustainable. For insights, we review health insurance moral hazard, agricultural infectious disease policy, and deterrence theory, but find that classic enforcement strategies of punishing noncompliant people are stymied. One mechanism is for policymakers to indemnify individuals for losses associated with taking those socially desirable behaviors to reduce the spread. We develop a coherent approach for doing so, based on conditional cash payments and precommitments by citizens, which may also be reinforced by social norms.