When there are joint authors of a work, each is a co-owner of the copyright in that work. This means that each author has the right to authorize publication of the work, use of it by a third party or the making of derivative works. It is very important, therefore, that joint authors agree in advance on how and when they wish to publish a work; conflicts develop when a single joint author authorizes a use of which the others do not approve, although such authorization is legal. Each joint author is responsible to account to the others for any profits received for the work.
Authors become joint authors when two or more each contribute protectable expression to a work with the intention that their contributions be combined into a unitary whole. Since intention is required, it is not possible to become a joint author accidentally. Contribution to a volume of essays or other collected work does not create joint authorship. Joint authorship is independent of academic rank or any other subordinate relationship (except that of employer/employee) ; a tenured professor, an adjunct instructor and a graduate student would all have equal rights in any work of which they were all joint authors.