Do airlines try to charge travellers more money if they search for a particular flight several times? Probably not, although there’s at least some evidence that browser history could influence the prices consumers see online.

Time reports that Rick Seaney of airfare search site FareCompare said that variances in price are more likely due to supply-and-demand or website errors than a reaction to a traveller’s repeated interest in a particular trip.

“If the airlines were to raise prices because of browser cookies there would be air travel whistleblowers and Senators running to microphones for legislation to prevent it,” said Seaney.

“What people see when they shop multiple times and prices are changing is a reflection of inventory changes, data caching techniques and the fact that prices generally get more expensive closer to departure date, even within a day.”

A 2016 study by Consumer Reports found that searches for flights with browser cookies turned off — effectively eliminating the ability of booking engines to see search history — tended to yield lower airfares than searches with cookies enabled. But researcher William McGee was unable to pinpoint a reason for the discrepancy.

“Our takeaway advice is that consumers shop around, and … if its possible, to search on at least two different browsers,” McGee said. “If you see different results … you clearly want to go with lower ones.”