The proportion of working-class actors, musicians and writers has shrunk by half since the 1970s, new research shows.

Analysis of Office for National Statistics data found that 16.4% of creative workers born between 1953 and 1962 had a working-class background, but that had fallen to just 7.9% for those born four decades later.

This reflected a similar decline in the number of people with working-class origins, according to the paper in the journal Sociology by researchers from the universities of Edinburgh, Manchester and Sheffield. People whose parents had a working-class job accounted for about 37% of the workforce in 1981, but by 2011 that had fallen to about 21%.

The finding raises questions about why years of attempts to make the arts more open and diverse have not had more impact – people who grew up in professional families were four times more likely than those with working-class parents to be in creative work, the study found.

And with fewer film directors, authors or songwriters to describe the experience of growing up in a working-class household, some creatives fear their stories are being squeezed out of culture or confined to “poverty porn”.

“These class imbalances have been with us for a long time,” said Dave O’Brien, a professor of cultural and creative industries at the University of Sheffield and one of the paper’s authors.

“It suggests that we need to do something more than just create access courses. It suggests that this is a big social problem, not just something that the BBC or the Arts Council or these kinds of organisations should be addressing.”

Actors such as Michael Sheen, Christopher Eccleston, Julie Hesmondhalgh and Julie Walters have said repeatedly in the last few years that finding a career in the creative industries has become much harder for people from traditionally working-class backgrounds.

The reality, says O’Brien is more complex. “The backdrop is this massive change in British society where there are fewer coal miners or manual labourers to have these kinds of working-class sons and daughters, so there are fewer working-class people coming through. And so the odds of people making it stay the same, even if the experience of the industry is really different.”

But the decline in numbers has other effects people should be concerned about, O’Brien said. “We know there’s clearly a relationship between who makes decisions, particularly in commissioning, and the kinds of stories that get made,” he said. TV commissioners and publishers come from a “reasonably kind of cohesive, quite narrow, elite social background” and may have a narrower view about what is interesting. He cited the BBC’s lack of appeal among people who are younger and from less privileged backgrounds.

That creates access problems even for success stories such as Gary Oldman, a sailor’s son from south London, Oscar winner and star of current Apple TV hit Slow Horses.

He has directed one film, Nil by Mouth, which won several awards including two Baftas in 1997.

“People say to me ‘Why haven’t you directed again?’ and it hasn’t been for want of trying,” he said at the BFI in October. “They don’t want another one of these [Nil by Mouth]. That’s the problem. They want Four Weddings and a Funeral.”

Natasha Carthew, the author of nine books including All Rivers Run Free, founded The Working Class Writers festival last year to address the issue.

“A lot of [working-class] writers think that people are going to be prejudiced right off the bat but that’s not the case,” she said. “People do want authentic voices. What makes it harder for them is later on, when you haven’t got the mates who are going to publicise your book.”

But publishers need to remember that books dealing with working-class life are not “poverty porn”, she added. “There are very different stories, about resilience and beauty and humour and hard graft.”

The lack of ability to take risks is another barrier, Carthew said, such as working two jobs or not having money to go out for drinks to build a network or pay for a hotel in London while doing an internship.

“Publishers are trying more to get a broad church of people,” Carthew said.

“But they’ve been slow, like everywhere’s been slow.

“There are lots of schemes, and then the money runs out – they’ve ticked that box and then they move on and put their cash somewhere else. I’ve seen that with my festival. That’s why the momentum keeps changing. They want novelty.”