Stieg Larsson's Millennium trilogy is good business for Stockholm, a new study has found.

The production of the movies based on the late best-selling Swedish author’s crime novels -- which are set in a nefarious world of murder, sexual fetishism, mental asylums and government corruption -- have spawned more tourism, new jobs, valuable branding and other spinoffs for the Swedish capital.

“The study shows that the movie is virtually unbeatable when it comes to marketing a region and a city," said Anders Ekegren, chairman of the regional film council for Stockholm and the Mälardalen area. “We also see the power of films to create jobs and economic growth at the local and regional levels.”

So far, the three films -- The Girl with the Dragon Tattoo, The Girl Who Played with Fire and The Girl Who Kicked the Hornets' Nest -- have been seen by some 20 million cinemagoers worldwide, while the books are breaking sales records all over the world.

The increased exposure is estimated to have been worth 960 million kronor ($150 million) to the Stockholm region. That value is expected to double in three years time.

During the making of the films, roughly 90 million kronor ($14 million) was spent on wages, hotels, transportation and the rental of locations in Stockholm.

Tourism has also been boosted as fans of the trilogy try to trace the characters’ footsteps. Some 10,000 people have been on guided walking tours that show the Stockholm venues used as backdrop in the films.

The study didn’t include any possible boost to the city’s profile as a result of the Hollywood versions of the movie, which star James Bond actor Daniel Craig as Mikael Blomkvist. But the report did say that tourism to Stockholm is expected to increase by more than 3 percent due to the so-called “Millennium effect”.

Olle Zetterberg, CEO of Stockholm Business Region, said that movies are a vital way of promoting Stockholm to the rest of the world.

“The creative industries, where the film industry is a big part, is important for the Stockholm region's competitiveness,” he said.

The report was produced by Cloudberry in collaboration with Oxford Research, commissioned by Filmregion Stockholm-Mälardalen, Stockholm Business Region Development, the Sörmland Regional Council, the Municipality of Nyköping and Film i Sörmland.