Is open access still open: the case of article processing charge

Open access (OA) is one of the most important initiatives in scientific publishing in modern age. Over time, its initial conception has gradually been altered by major scientific publishers which introduced changes in OA including article processing charge, a fee which covers preparation, publishing and archiving of scientific content. This paper presents results of an original research of presence and granularity of article processing charge in two major OA databases and at five major scientific publishers. The results indicate that while this fee represents a growing source of revenue for publishers, it also represents a growing problem for authors.