A pool is pro-competitive where the participating parties are able to use each other’s technology for further competing product development, and where the pool is open to be used by third parties, against the payment of a fee. Box 11 provides an example of such an open patent pool created by UNITAID for accelerated treatment of HIV/AIDS. On the other hand, patent pools may also have serious anti-competitive effects where participating parties agree on joint use of the technology, establish uniform prices of the resulting products, and refuse licenses to outsiders.