About 50 percent of scientific papers published in 2011 are now available for free, twice the level of previous estimates, according to a study funded by the European Commission. The study shows a positive trend towards open access to research findings, estimating more than 40 percent of scientific peer-reviewed articles published worldwide from 2004 to 2011 are now available online. \"Putting research results in the public sphere makes science better and strengthens our knowledge-based economy,\" Maire Geoghegan-Quinn, the EU\'s commissioner for research, innovation and science, said on Wednesday. The EU identifies open access as a core means to improve knowledge circulation and innovation in Europe. It is set to be mandatory for all scientific publications funded by the EU\'s research and innovation program titled Horizon 2020 from 2014 to 2020. According to the study, free availability of the majority of articles has been reached in such fields as general science and technology, biomedical research, biology and mathematics, while open access availability is most limited in areas of social sciences and humanities, applied sciences and engineering and technology. The study was undertaken by a research evaluation consultancy and included 28 EU member states as well as the United States, Canada, Japan and Norway, among others.