From the 2015 Horizon Report:
Proliferation of Open Educational Resources Mid-Term Trend: Driving Ed Tech adoption in higher education for three to five years.
Open textbooks are being considered as a viable means for cutting excess costs with the goal of making education more affordable for students. According to a 2014 study by US PIRG Education Fund and the Student PIRGs, of 2,039 students surveyed, 65% said
that they had not bought a textbook due to its high price. Open textbooks are open-source e-books that are freely available with nonrestrictive licenses, and have been popularized by projects such as Rice University’s Open Stax College and College Open Textbooks, a
non-profit collaborative of over 200 universities and 29 organizations.