Hybrid open access journal

# Overview
A newly popular variation on open access journals is the Hybrid Open Access Journal. This refers to a journal where only some of the articles are open access. This status typically requires the payment of a publication fee (also called a processing fee) to the publisher.

# Terminology
Hybrid OA Journal seems to be the customary term, although  OA by the Article and Optional OA have also been used. Open Choice, which properly means Springer's scheme, is sometimes used as the generic. From its originators, it has also been called the Walker-Prosser model for open access journals.
Open Access may be defined differently by different publishers. Open access involves more than free access. Permission barriers should also be minimized. For example, there are various versions of Creative Commons Licenses. The most restrictive of the six main Creative Commons Licenses allows anyone to download authors' works and share them with others, provided that the works are properly attributed and linked back to the original authors, and also provided that the works aren't changed in any way, nor used commercially. Other licenses are more accommodating.

# History
The concept was first proposed a few years ago.  Thomas J. Walker first suggested that authors could purchase extra visibility at a price.  The first journal recognized as using this plan was Walker's own Florida Journal of Entomology; it was later extended to the other publications of the Entomological Society of America.  The idea was later refined by David Prosser in 2003 in the journal Learned Publishing.

# Publishers and names
Each publisher that offers this plan uses a distinctive name, as listed below:
- AlphaMed Press: Open Access Option (described in the Information for Authors).
- American Chemical Society: AuthorChoice.
- American Dairy Science Association: Open Access at JDS
- American Physical Society: Free to Read.
- American Society of Animal Science: Open Access option.
- American Society of Limnology and Oceanography: .
- American Society of Plant Biologists: Open Access Experiment.
- Blackwell Publishing: Online Open.
- BMJ Publishing Group Ltd: BMJ Unlocked.
- Cambridge University Press: Cambridge Open Option.
- Cold Spring Harbor Laboratory Press: Open Access Option.
- Elsevier: Sponsored Article.
- International Union of Crystallography: Open-access.
- John Wiley & Sons: Funded Access.
- Longwoods Publishing: Optional Open Access
- Mary Ann Liebert, Inc.: Liebert Open Option
- Oxford University Press: Oxford Open.
- Royal Society (UK): EXiS Open Choice.
- Royal Society of Chemistry (UK): RSC Open Science.
- Society for Endocrinology: Free Access Option.
- Springer: Open Choice.
- Taylor & Francis: iOpen Access.
- United States National Academy of Sciences: PNAS Open Access Option.
- World Scientific: WorldSciNet OPEN ACCESS.
See also Category:Hybrid open access journals

# Postulated effect on subscription prices
Since one of the proposed sources for the necessary funds for open access articles might be the library subscription budget, there needs to be a decrease in the subscription cost to the library.
Therefore the article payments must not  merely add to the normal subscription cost, but rather reduce the cost. Springer's Open Choice was the first to provide a specific way to reduce the subscription price: the proportionate increase in the author-financed articles, would provide a proportionate reduction in the cost (along with a number of complicated provisos and exceptions).  This soon prompted most of the other publishers to offer similar provisions, though initially they were still usually indefinite. Because of the processes in pricing journal subscriptions, fees paid for an article would be reflected in prices for the journal only two years later: fees paid for  2006 would be known in 2007, and affect the prices set for the 2008 journal subscription year.  
In some cases less was offered: the publishers of PNAS promised to use the money to offset some of the increase in future author fees and prices.

# Advantages and disadvantages for the publisher
One of the difficulties with "full" open access journals, or the subset of them that charge author-side fees, is the difficulty of getting started.  The publisher must be ready to take the risk of not having subscription income, in the hope that payments will materialize.  But with a hybrid open access journal, the publisher only provides open access to those articles for which the payment is made.  To the extent the plan succeeds, the publisher has an adequate revenue stream from fees.  To the extent that it fails, the publisher has an adequate revenue stream from subscriptions.

# Advantages and disadvantages to the author
The author wanting to publish in an open access journal, is not limited to the relatively small number of "full" open access journals, but can also choose from the available hybrid open access journals, which includes journals published by many of the largest academic publishers.
The author must still find the money. Many funding agencies are ready to let authors use grant funds, or apply for supplementary funds, to pay publication fees at Open Access journals.  (Only a minority of Open Access journals charge such fees, but nearly all hybrid Open Access journals do so.)  So far, the funding agencies that are willing to pay these fees do not distinguish between full and hybrid open access journals.

# Variations
The American Society of Plant Biologists (ASPB) has adopted a unique policy that articles contributed by society members to its journal, Plant Physiology, will be made Open Access immediately upon publication at no additional charge. Non-member authors can receive OA through payment of $1,000, but since membership is only $115/year, it is expected this initiative will boost membership.