Single-handedly boosting the U.S. hotel industry, investment bank Bernstein wrote a report praising the "bad economic effect"

Bernstein, a well-known American investment bank, said in a report on Friday that Taylor Swift's eye-catching "Eras" tour has boosted hotel revenue in various U.S. cities. As tours go international, this so-called “hard economics effect” can be seen around the world.

"This is a significant boost to the hotel industry," Bernstein analyst Richard Clarke wrote in a note.

Bernstein data shows that in the months since Swift's visit, average revenue per room in U.S. states was more than 4 percentage points above the national benchmark. Revenue per room in these states increased by an average of about 7% compared to the same period last year. (Revenue generated per room is calculated by dividing total hotel revenue by the number of available rooms, regardless of whether the rooms are occupied.)

Clark said the increase in revenue was primarily due to rising hotel room rates, but in many cases bookings were also up. In the most extreme example, hotel occupancy rates in Nashville rose by more than 30% on the night of Swift's concert, and room rates increased by more than 50%. Revenue per room more than doubled the weekend Swift visited.

Clark noted that given the tour is an international one, other countries will have a chance to feel Swift's impact.

Meanwhile, Bernstein found that Beyoncé's "Renaissance" tour also had a significant boost to the hotel industry, although its impact was relatively small compared to Swift's tour.

The so-called "hard economics effect" also caught the attention of the Fed, who specifically noted high hotel bookings during Swift's stay in Philadelphia.

"Despite a slowdown in the region's overall tourism recovery, one source highlighted that May was Philadelphia's strongest month for hotel revenue. This was due in large part to an influx of guests attending Taylor Swift's concert in the city," Fed officials wrote in the Beige Book summarizing economic activity in July.

In fact, Clark said Philadelphia hotel occupancy increased 11% while Swift was on tour, while revenue per available room increased an average of 59%.