Why cash incentives and lotteries for covid-19 vaccinations failed

What does it take to get one?
What does it take to get one?
Image: Reuters/Gaelen Morse)
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When covid-19 vaccines were first rolled out in the US, government officials and corporations spent months using various tactics to convince the hesitant, from paying them to get their shot to giving them free donuts.

The number of unvaccinated adults in the US, which stands at around 80.2 million despite wide vaccine availability, was already evidence of the limited success of these kinds of measures. Now research confirms it. A couple of papers published in recent days found that neither cash payments nor lottery tickets moved vaccine-reticent Americans to get the jab.

The pandemic presented an unprecedented opportunity for behavioral economists to test what they call “nudging”, or setting up choices so it’s easier for people do the right thing. For example, putting fruit instead of junk food at eye level increases the chances of someone reaching out for an apple instead of a candy bar. That approach has worked in the past—including to boost flu vaccination rates. But the degree of political polarization and disinformation swirling around vaccines calls for more forceful policies, such as mandates, the research suggests.

Nudges can backfire

One of the studies, published by the National Bureau of Economic Research on Monday (Oct. 25), followed members of a Medicaid program in Contra Costa County, California from mid-May to mid-July, months after vaccines first became available. They were asked to fill out a survey and watch informational videos about the covid-19. The researchers then randomly selected people to receive a cash reward of $50 or $10 upon getting vaccinated if they did it two weeks after taking the survey.

The study found offering small payments didn’t move the needle on the vaccination rate; in fact, among older people who voted for Trump, they lowered it.

The other paper, published in JAMA Health Forum, looked at lotteries. It compared states with vaccine lotteries to those without them, and found no difference in the vaccination rates between the two.

Vaccine intentions are not the same as vaccinations

That’s not to say nudges are completely useless. A research paper published in Nature in August found that text reminders to get the covid-19 shot made a difference. The study looked at people who had received an initial invitation to schedule an appointment from their healthcare provider. About 14% of those who didn’t receive a follow-up message got vaccinated, compared to up to 18% among those who did. (Second reminders seemed to have less of an effect on people who ignored the first follow-up message.)

A caveat of that study, though, is that it was conducted early on in the vaccination drive, so it doesn’t shed much light on how these interventions would work among long-time holdouts.

One lesson for policymakers, who spent months trying a hodgepodge of tactics without much success, is to be more systematic and diligent about studying what works and what doesn’t, Alison Buttenheim, a public health and behavior science researcher at the University of Pennsylvania, told Quartz. Had they done that, they would have perhaps rolled out mandates a lot sooner.