Next time you’re traveling someplace and you’re checking reviews you may want to take them with a grain of salt — especially if it’s a high-end hotel. According to a new study, high-end hotels don’t shy away from manipulating their reviews to get ahead of Airbnb, and surprisingly, low-cost hotels don’t really do the same.

If you’re traveling someplace, hotels and other similar accommodations are no longer the only options. Sure, there have always been fringe alternatives like camping, but I’m talking about Airbnb — the business that has singlehandedly disrupted the accommodation industry. Airbnb enables people to open their own homes and accommodate business, bringing the gig economy into your home, quite literally.

Airbnb has its own drawbacks and issues, but it’s put a lot of pressure on hotels. Suddenly these businesses no longer had to compete with one another, but they had to compete with regular folk with a spare bedroom as well. Also, since people who travel with AirBnB tend to be a bit savvier, reviews matter more than ever.

Of course, review manipulation is nothing new. Before Airbnb even emerged as a business, some hotels were engaging in this practice, creating fake customers to leave fake reviews. In some cases, up to a third of a hotel’s reviews could be fake.

“We know hotels adapted to the competition with Airbnb by lowering prices, but we wanted to know if there was something else hotels were doing,” said Cheng Nie, assistant professor of information systems and business analytics at Iowa State University, co-authored the research.

Nie wanted to see if Airbnb entering the scene changed anything. He focused on the period from 2008, when Airbnb was launched, to 2016, and looked at accommodations in Texas, looking at 2,188 hotels in 67 Texas cities. He compared reviews on Tripadvisor, where anyone can post a review of a hotel (and fake reviews are much more likely), and Expedia, a site that only allows reviews from customers who have made a verifiable reservation. Reviews through Expedia could also be falsified, but it is much harder as people would actually need to pay for a room to post a fake review. A big difference between the two websites was interpreted as an indication of fake reviews.

Remarkably, Nie found that low-end hotels didn’t do much to adapt. He interprets this as people being unfussy about the cheaper accommodation they choose to stay in.

“A lot of people who stay at low-end hotels are less likely to pay attention to reviews compared to people trying to decide if a $500 resort is worth their money,” said Nie.

But meanwhile, hotels that do charge a lot did also change their reviewing strategy and seemed to have fake reviews.

“We have shown the evidence that if there are more Airbnb listings available around high-end hotels, those hotels tend to self-promote more by posting fake positive ratings. Consumers need to be careful because the reviews, especially on Tripadvisor, may be inflated and not be truly representative of the quality,” said Nie.

The study could have real-life repercussions, Nie says. He warns people to be skeptical of inflated ratings that may not be representative of quality. A good strategy could be to look for reviews on different websites, especially those that make it harder to add fake reviews.

This study adds to the already existing evidence on faking reviews — and research also suggests that we’re not as savvy as we’d like to think when it comes to picking fake reviews. We tend to be misled by high reviews and it’s something worth keeping in mind when you make that next booking.

Nie also says there’s more to be learned here. He wants to continue studying the shared economy and plans on focusing on how Airbnb affects hotel strategies to compete for customers and are most effective.

The research paper can be read entirely here.