Can Cash Coax the Hesitant To Take the Vaccine?

Researchers test the proposition in two studies and reach opposite conclusions

Doctor vaccinating a woman

Luis Alvarez/Getty Images

Can small financial rewards nudge people into getting vaccinated against COVID-19? Or have incentives lost their effectiveness, leaving government mandates like the one detailed by the White House on Thursday as the only good option to ensure more people are protected from the pandemic?

Key Takeaways

  • Two studies published last week, each examining whether small cash rewards can encourage people to get vaccinated against COVID-19, reached opposite conclusions.
  • In one study, cash rewards were ineffective at persuading Medicaid recipients to be immunized. 
  • In the other, vaccine clinics that offered $25 cash rewards delivered more vaccines than clinics that didn’t. 
  • The researchers agreed that vaccine mandates, such as the one detailed by the White House on Thursday, would be needed to get immunization rates high enough to quell the pandemic.

A pair of papers released last week attempted to answer that question—and reached opposite conclusions. A team of researchers at the University of Southern California (USC) conducted an experiment on whether sweeteners of up to $50 would convince unvaccinated Medicaid recipients to get the shot. The team also studied the effect of public health messages, and found neither cash nor messaging worked. Another study, by researchers at the North Carolina Department of Health and Human Services and other institutions, found that clinics that offered $25 rewards for getting vaccinated—or for driving someone to get the vaccine—had better vaccination rates than clinics elsewhere.

Policymakers and business leaders have tried a mix of “carrots” (incentives) and “sticks” (mandates or penalties) to increase vaccination rates to slow the spread of the coronavirus and protect their employees from hospitalization and death. The carrots have ranged from New York’s $100 cash rewards and Ohio’s $1 million lotto for vaccinated residents to New Jersey’s “shot and a beer” program, which made a vaccine card good for a cold one at local breweries. 

Notable among the sticks is the federal mandate, which says that companies with more than 100 employees must require their workers to either get vaccinated by Jan. 4 or produce a negative test at least every week. Some major employers have already announced their own policies, including Ford Motor Co., which is reportedly requiring vaccines for 32,000 salaried workers, and Delta Air Lines, which imposed a  $200-a-month penalty for unvaccinated employees

The latest research attempts to shed light on the question: Are the carrots still worthwhile?

“The answer, sadly, appears to be no,” said Tom Chang, an associate professor of finance and business economics at USC, who ran the first study. “I thought some of these things would work, but as I often am, I was just wrong.” 

Charlene Wong, chief health policy officer for COVID-19 at the North Carolina Department of Health and Human Services, says her research supports a different conclusion.

“Policymakers across the country and across the world are trying to figure out how to get as many people vaccinated as possible so we can put this pandemic behind us,” she said. “We were able to demonstrate that these small guaranteed financial incentives should be considered as part of the strategy.”

Reducing Barriers

Wong’s paper looked at what happened at four North Carolina clinics that offered $25 rewards to people for getting the vaccine, and the same amount to people who drove others to an appointment. The idea was to reduce barriers to getting the vaccine, especially for people who have limited access to transportation or who needed to offset the cost of lost wages and childcare. 

While vaccination rates declined throughout the state during the time the study was conducted, they fell less at the clinics where the $25 rewards were offered. Not only that, but about 9% of people who got vaccinated at the clinics said they wouldn’t have done it without the cash reward, while about 15% said they’d waited to get the shot until they found a place offering a reward.

The study was run during a two-week period in late May and early June—a time when vaccines had been available to all North Carolina adults for more than a month, and when more than half the adult population of that state had already been given at least one shot. 

Wong believes the numbers show that incentives matter for people with limited resources who might otherwise have difficulty getting to a vaccination site. 

“I think there are a lot of populations for whom it’s a real challenge,” she said, adding that the trial “really promoted access among historically marginalized populations” such as low-income, Black, and Hispanic residents who she said have a harder time than other groups getting vaccines. 

A ‘Depressing Result’

The USC researchers tried one of several methods on randomly chosen Medicaid recipients in California’s Contra Costa County: either offering them financial rewards between $10 and $50, showing them videos with different public health messages, or directing them to a convenient online appointment scheduler. They then asked the subjects whether they planned to get vaccinated, and followed up a month later to see if they actually did. 

As it turned out, some of the public health videos—especially those warning of the dangers of going unvaccinated—increased the number of people who said they would get the vaccine, but they had no effect on actual vaccinations. Similarly, the financial rewards had no impact, and may have even backfired somewhat by making vaccine-hesitant subjects suspicious about why they were being cajoled with money. 

The study led by USC’s Chang was conducted between May and July—again, after vaccines were widely available in California including in Contra Costa County, an area that had opened up vaccine eligibility to all adults in March. The county also had a very high vaccination rate, thanks to getting an ample vaccine supply early on, meaning that Chang’s experiment took place among a population that remained unvaccinated even after having had plenty of opportunity to be immunized. 

Chang said his study demonstrates that while prodding people with messages and rewards might work on people who are open to getting a vaccine—but just haven’t done so yet—they are ineffective with people who have declined for months to get vaccinated, even though the shots have been conveniently available. 

“It’s been pretty easy to get a vaccine now for quite some time,” Chang said. “I don’t think you have a lot of people saying, ‘Oh yeah, I meant to get vaccinated, but I haven’t gotten around to it yet.’”

And if carrots have lost their appeal, that leaves authorities with one less option.

“The sort of depressing result of the paper is that the carrots don’t seem to work much anymore,” Chang said. “And we’ve seen at least some early evidence that sticks work really well. We need something stronger than trying to encourage people to get vaccinated on their own.”

Which of the researchers’ two conclusions is more valid is up to the scientific community to hash out. 

But Chang and Wong did agree on one thing: Mandates should be part of any effort to increase vaccination rates.

“Multiple strategies are what will really be needed,” Wong said. “We really need a very, very high vaccination rate to put the pandemic behind us.”

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