Can Yankee Candle reviews predict COVID surges? Study puts theory to test — and experts weigh in.

The Centers for Disease Control and Prevention quietly announced on Oct. 5 that it will no longer provide public information on daily COVID-19 cases and deaths across the U.S. Instead, the CDC plans to release weekly data reports beginning on Oct. 20, which marks a big change from the information the agency has shared during the majority of the pandemic.

The CDC's data has been viewed as a dramatic undercount for months due to just how many people are testing for COVID-19 at home and not reporting their results to local health authorities (who then notify the CDC), John Sellick, an infectious disease expert and epidemiological researcher at the University at Buffalo/SUNY, tells Yahoo Life. So, that's led people to try to find indicators of the next COVID-19 wave in other areas — like Yankee Candle reviews.

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Yes, people are actually looking at reviews for the popular candle company to try to predict if there will be a rise in COVID-19 cases. The connection is fairly simple: When there's a rise in reviews from people who say that their candles have no smell, there will also be a rise in COVID-19 cases. The theory, as it stands, is that these people are actually infected with COVID-19 and don't realize it.

While there's a healthy dose of skepticism around this concept, there's actually some data to support it, courtesy of Nick Beauchamp, an associate professor in the department of political science at Northeastern University.

Beauchamp tells Yahoo Life that he first dove into the data surrounding Yankee Candle reviews and COVID-19 cases after spotting memes that linked the no-smell reviews to a rise in cases. "Mostly the memes were laughing at the idea of people having COVID, not knowing it and blaming candles," he says. Beauchamp says he "had a couple of spare hours," so he looked into the data and found a link to a rise in these reviews and a jump in COVID cases. He shared the image on Twitter and it went viral. "I said, 'Oh, shoot — I guess I have to do this properly,'" he explains.

Beauchamp ended up writing a scientific paper on his findings. He used a Google Chrome extension that grabbed 9,837 Amazon reviews for the four most popular Yankee Candles during a 172-week period between 2018 and 2021. He then calculated the percentage per week of reviews that mentioned phrases like "no smell" or "no scent" and plotted that data over information on COVID-19 cases during the same period. He also controlled for factors such as seasonal upticks of candle purchases and COVID-19 cases.

He discovered that a rise in COVID-19 cases also led to an increase in bad reviews for candles — specifically, for every 100,000 new COVID-19 cases a week, there was a quarter of a percentage point increase in "no smell" reviews the following week.

Yahoo Life reached out to Yankee Candle, but did not immediately receive a response.

Experts are doubtful, though, that this is a reliable way to tell if a COVID-19 wave is coming. "I laughed pretty hysterically when I first saw this," Sellick says, noting that there are a few reasons this isn't a reliable predictor.

"COVID is not the only thing that causes loss of taste and smell," he says. And, while previous variants of the virus caused loss of taste and smell, the Omicron variant — which is dominant in the U.S. right now — in particular is not linked to this. Infectious disease expert Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, tells Yahoo Life that there's just too much "noise" to make this a valid indicator.

"It's just very hard to separate signal from noise," he says. "How many people with COVID buy Yankee Candles, can't smell it and then actually write a review about it? If you had a little village where everybody buys them and writes reviews, it could be a good signal. But that's not the case."

Even Beauchamp is doubtful this is actually a thing. "I retain a healthy skepticism that this is real," he says.

Beauchamp says all the chatter about his work — including by doctors — is an indicator that the data on COVID-19 isn't that good. "It's becoming less accurate as we go," he says. "People are testing less [frequently] and submitting their results much less [frequently]."

"The fact that health professionals are now talking about this illustrates where we are with the data," he continues. "The official measures have gotten so unreliable that we're forced to turn to other measures."

While experts say this is a fun experiment, they're not putting too much stock in it. "This is pretty much witchcraft," Sellick says. "We have not done a very good job with predicting anything with this pandemic. I, for one, will not be checking out candle reviews to try to see if a wave of COVID-19 is coming."

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