'Epidemic of invisibility': USC report highlights Hollywood's diversity crisis
Oscar statute (Joe Seer / Shutterstock.com)

Hollywood is suffering an "epidemic of invisibility" among ethnic minorities, women and LGBT people, a new study showed Monday, just days ahead of the film industry's glittering Oscars awards night.

From the boardrooms of film and television studios to the actors in front of the camera, the industry is overwhelmingly white, male and heterosexual, the report by the University of Southern California found.

"This is no mere diversity problem. This is an inclusion crisis," said Stacy Smith, of USC's Annenberg School for Communication and Journalism, who authored the report.

The study comes with a social media campaign under the hashtag #OscarsSoWhite threatening to overshadow the Academy Awards on Sunday, the culmination of Hollywood's annual awards season.

No ethnic minority actor or actress has been nominated in any of the top categories for the second year running, sparking an outcry against the Academy of Motion Picture Arts and Sciences.

"Overall, the landscape of media content is still largely whitewashed," concluded the report, which looked at Hollywood output aired from September 2014 to August 2015.

Of 11,300 speaking characters in 414 film and TV series studied by researchers, one third were female while just 28 percent were ethnic minorities, far short of the proportion in society at large, usually given at somewhere approaching 40 percent.

Just two percent were LGBT-identified, while 74 percent of characters aged over 40 were men.

Around half of the 305 shows and 109 movies did not feature a single Asian or Asian-American character while a fifth had no black characters.

Behind the camera, just 15 percent of directors, 29 percent of writers and 23 percent of series creators were female.

"The hashtag #OscarsSoWhite should be changed to #HollywoodSoWhite, as our findings show that an epidemic of invisibility runs throughout popular storytelling," the report said.

The study reflects the 2015 Hollywood Diversity Report, produced by the University of California, Los Angeles, which found that ethnic minorities were under-represented on every front, from leading acting roles and directing to writing and reality television.

Film studio heads were 94 percent white and 100 percent male, while senior managers were 92 percent white and 83 percent male. The pattern was repeated in television.

The Academy's board, smarting from claims of institutional racism, has announced that by 2020 it will double the number of women and people from minority backgrounds among its voting members, which it currently puts at 24 percent and seven percent respectively.