It was a tweet that started out as a joke: Twitter user Nick Beauchamp pointed out a rise in negative reviews of Yankee candles back in 2020, linking it to COVID-19 cases.

Beauchamp, a statistician and political science professor at Northeastern University, argued that the increasing number of reviewers stating that their recently purchased Yankee candles had “zero smell” suggested that COVID-19 cases were rising again.

The tweets went viral, and people joked about how something as mundane as candle reviews could become a legitimate predictor of the disease.

But Beauchamp, whose research includes examining social media trends and posts in relation to political outcomes, felt his hunch was a sign of something bigger. Now Beauchamp’s tweets have been backed up by research – and his hypothesis proved to be on the money in a study that was presented at the International AAAI Conference on Web and Social Media.

“It was recently hypothesized that an inadvertent indicator of this key symptom may be misplaced complaints in Amazon reviews that scented products such as candles have no smell,” Beauchamp wrote in the study. “This paper presents…that ‘no smell’ reviews do indeed reflect changes in U.S. COVID-19 cases even when controlling for the seasonality of those reviews.”

Some of the Amazon reviews included statements like “no scent” and “no scent, disappointing.”

The study, which analyzed data through December 2021, found that rising numbers of COVID-19 cases often presaged an increase in one-star reviews of Yankee candles. Beauchamp wanted to determine whether the opposite was true – whether these reviews could predict an upward case surge.

He continued to add data to his model and, in June 2022, found that the reviews could possibly predict COVID-19 cases. In fact, they served as an earlier prediction than official COVID-19 data. State and federal monitoring of COVID-19 data has lagged throughout the pandemic and in recent months has become even less of a priority.
In an interview with The Guardian, Beauchamp cautioned that the candle data was “fairly minor and idiosyncratic.” Still, as fewer people quarantine when ill and receive their booster shots, an inability to smell those seasonal pumpkin spice candles may be a symptom to monitor.