The abstract is below:
The article processing charge (APC) is currently the primary method of funding professionally published Open Access peer reviewed journals. The pricing principles of 77 OA publishers publishing over 1000 journals using APCs were studied and classified. The most commonly used pricing method is a single fixed fee, which can either be the same for all of a publisher’s journals or individually determined for each journal. Fees are usually only levied for publication of accepted papers, but there are some journals that also charge submission fees. Instead of fixed prices many publishers charge by the page or have multi-tiered fees depending on the length of articles. The country of origin of the author can also influence the pricing, in order to facilitate publishing for authors from developing countries.Part of the conclusion follows:
In the same way as innovative entrepreneurs in other fields such as digital sales of music and mobile telephony, OA publishers have experimented with different pricing mechanisms. Many of the pricing principles correspond directly with the cost structure of publishing whereas others with the author’s ability to pay. Among the big (≥ 10 journals) publishers, mainly commercial companies, the individual journal by journal pricing using fixed prices seems to be the dominant mode. Waivers for less endowed authors are used by half of these publishers. Institutional membership schemes are quite common in this category.
A slight majority of the single journal publishers use page charges rather than fixed pricing. Since the majority of these are scientific societies we could speculate that they as publishers historically might be familiar with using page charges also in subscription journals. Submission charges are quite rare, especially among the bigger publishers. . . .