New research has found that the market share of the world's largest research publishing houses has skyrocketed since the 1970s, with five corporations now controlling 50 percent of all the journal articles that are published.

The study also found that, while these companies charge large fees for people to access this research, they don't add much value themselves - suggesting that the current model is no longer in the best interests of scientists or universities.

"These large commercial publishers have huge sales, with profit margins of nearly 40 percent," study leader Vincent Larivière from the University of Montreal in Canada said in a press release. "While it's true that publishers have historically played a vital role in the dissemination of scientific knowledge in the print era, it is questionable whether they are still necessary in today's digital era."

Publishing their results in the open-access journal PLOS ONE, the team looked at all scientific articles published in the Web of Science database between 1973 and 2013, and found that five companies have published more than half of them since 2006: Reed-Elsevier, Taylor & Francis, Wiley-Blackwell, Springer and Sage.

Back in 1973, the same publishing houses controlled just 20 percent of the journals, and 30 percent in 1996. But over the past two decades, that has rapidly increase thanks to a slew of rapid mergers and acquisitions.

Some fields are more independent, in particular the areas of biomedical research, physics, and the arts and humanities. But the team found that almost 70 percent of journal articles published in chemistry, psychology and social sciences are owned by the big players. 

What makes things worse is that the publishers have now established an incredibly lucrative business model based on taking advantage of scientists to create content for them for free, and then selling it to back to them once it's published. In fact, publishers don't even pay for quality control - which is done by other scientists for free in the form of peer review - and their overheads are much lower since the arrival of the Internet.

All of this begs the question: what exactly are we paying these big publishers for? "One would expect that a major publisher acquiring a journal would have the effect of increasing the latter's visibility. However, our study shows that there is no clear increase in terms of citations after switching from a small to large publisher," said Larivière.

This isn't the first time the publishing model has been criticised - over the past couple of years, researchers and universities have begun to protest against the monopoly in publishing. The Cost of Knowledge campaign, which calls for a boycott of Elsevier's journals, has been signed by more than 15,000 researchers.

But unfortunately while young academics still need to publish in high impact journals to get hired, scientists will have to submit their articles to these companies. And as long as the most important research in each field is stuck behind a paywall, universities will pay for their researchers to access it, creating a cycle that keeps the big publishers in business.

Still, hopefully research such as this will help scientists realise that they don't need publishers to help them distribute their content anymore. "Our findings question the real added value of big publishers," said Larivière. "Ultimately, the question is whether the services provided to the scientific community by these publishers warrant the growing share of university budgets allocated to them."