The global shift towards making research findings available free of charge for readers is reaching the tipping point, with around 50% of scientific papers published in 2011 now available for free, according to a new study conducted for the European Commission. 

This is about twice the level estimated in previous studies, and this is explained by "a refined methodology and a wider definition of open access," says the study, which also reports that more than 40% of scientific peer-reviewed articles published worldwide from 2004 to 2011 are now available online in open-access form.

The study looked at the availability of scholarly publications in 22 fields of knowledge in the European Research Area, Brazil, Canada, Japan and the US. In a number of countries and disciplines, over 50% of papers are now available for free, and this level has been reached for most articles in the fields of general science and technology, biomedical research, biology and mathematics and statistics. The fields where open-access availability is most limited are the social sciences and humanities and applied sciences, engineering and technology, it reports.

Most of the 48 major science funders surveyed consider both key forms of open access - open-access publications in journals and self-archiving - to be acceptable, and over 75% accepted embargo periods of 6-12 months.

However, the investigators - from the research evaluation consultancy Science-Metrix - also found that there are currently still fewer policies in place for open access to scientific data than for open access to publications. They note that open access to research data is rapidly evolving in an environment where citizens, institutions, governments, non-profits and private companies loosely cooperate to develop infrastructure, standards, prototypes and business models. 

"Open access is here to stay," said Maire Geoghegan-Quinn, European Commissioner for Research, Innovation and Science. "Putting research results in the public sphere makes science better and strengthens our knowledge-based economy."

This is why open access will be mandatory for all scientific publications produced with funding from Horizon 2020, the EU's research and innovation funding programme for 2014-2020, the Commissioner added, commenting: "the European taxpayer should not have to pay twice for publicly-funded research."

Also under Horizon 2020, the Commission will start a pilot on open access to data collected during publicly-funded research, "taking into account legitimate concerns related to the grantee's commercial interests, privacy and security," say officials.