This is why vaccine lottery prizes may work for some, according to psychology experts

Maryland drew a winner for its first $40,000 vaccine lottery prize Tuesday, kicking off 40 days of drawings meant to encourage state residents to get the COVID-19 vaccine.

The campaign, called VaxCash, will automatically enter vaccinated Marylanders into daily $40,000 lotteries from May 25 until July 4, when a $400,000 prize will be randomly awarded. To be eligible, residents must have received the vaccine in the state and be 18 years old or older. While states like Delaware, New York and Kentucky have instituted their own versions of cash lotteries to incentivize people to get vaccinated, the idea was popularized in Ohio, where vaccination rates jumped 33% the week after the state announced its $1 million Vax-a-Million lottery, according to an Associated Press analysis.

"This dramatic increase in vaccinations indicates that the Vax-a-Million drawing has been impactful in creating momentum for vaccinations throughout Ohio," Stephanie McCloud, director of the Ohio Department of Health, said in a statement.

In recent weeks, states and municipalities have encouraged people to get vaccinated with a slew of incentives, including free concerts, pizza, beer and cash. But unlike free pizza, winning the lottery isn't guaranteed. So what's so enticing about a chance to win big that's prompted unvaccinated people in Ohio to get the shot?

"It's actually very clever, in a way," said Robert Williams, a professor in the faculty of health sciences at the University of Lethbridge and a research coordinator for the Alberta Gambling Research Institute in Canada.

Part of human nature is that we're not used to remote outcomes, Williams explained, which makes it hard for our brains grasp them. Lottery winners are publicized in the newspaper and you may know someone who knows someone who once won. Having any connection to an event, however slight, makes the odds seem higher than they actually are.

"I never buy lottery tickets. The chances of winning are so astronomically remote," Williams said. "Most people don't think that way."

When odds get low enough, the numbers themselves cease to matter, according to Nichole Lighthall, an assistant psychology professor at the University of Central Florida. "People don't compute possibility that way," she said. "Small is just small."

Those who are hesitant to get vaccinated because they fear unlikely side effects might actually be "optimally suited" for a vaccine lottery incentive, according to Williams.

"If you can convince yourself you have a realistic possibility of winning the lottery, you may be the same kind of person who has an unrealistic view of blood clots," he said. "You've given disproportionate weight to unrealistic outcomes."

Risk vs. reward

Even with infection rates falling in the United States, for the unvaccinated, the risk of contracting COVID is still real. But from a psychology perspective, people evaluate gains and losses differently, according to Lighthall.

Vaccinations can be a tougher sell because there aren't obvious gains, she explained. Usually, the best-case scenario after getting vaccinated is not getting sick with COVID-19, so now that people have more to gain -- like money -- some are more inclined to go through with the vaccination, Lighthall explained. People also tend to focus on losses, or factors they find unpleasant, such as a needle prick or feeling sick after getting the shot. When comparing a certain loss, like a needle prick, to the risk of a bad event, like getting COVID-19, "they prefer to take the risk of possibly getting COVID as opposed to something they are sure will happen, like needles or feeling uncomfortable."

"When people are faced with uncertainty it's really stressful for them," she added. "A safe place to retreat to is the status quo."

Lotteries are also attractive because they are framed through a positive lens. Advertisements promote the chance you could win, not the much higher likelihood that you'll lose. That positivity draws people in. By contrast, when we talk about vaccines, "we often focus on the negative," Lighthall said. "There's a chance it might not work. There's a chance of side effects."

'A natural experiment'

While a review of research published prior to the pandemic did not find strong evidence to suggest that interventions, including monetary rewards, had much of an effect on vaccination rates, past vaccination campaigns have largely focused on children, not adults.

Lighthall is curious to see how states' vaccine lotteries play out over time. "It's a little bit of a natural experiment that's happening right now," she said. "It's using the right principals of positive framing, so it has that going for it. I hope it works."

And yet, she suspects that programs offering guaranteed rewards, such as West Virginia's program to give vaccinated young people $100 savings bonds or gift cards, may have a larger impact on vaccination rates than lotteries do.

"Particularly for people who don't have very much money, it's meaningful. It's not peanuts," she said. "People like to gamble, but people love to get money for sure even more."