The 1976 Copyright Act defines joint ownership as requiring an "intent" by multiple authors to merge their works into a single work. Prior to 1976, two standards of determining intent existed in the case law. One was an objective standard, known as common design, and the other was a subjective standard. In part because the 1976 Act does not mention common design, subjective intent came to dominate joint authorship jurisprudence post-1976. As a result of this dominance, many authors have been deprived of their rights. Brady argues that a new standard should be set out by the courts that once an author is aware that his work will be part of a larger work, joint authorship is established.
Therese M. Brady,
Manifest Intent and Copyrightability: The Destiny of Joint Authorship,
17 Fordham Urb. L.J. 257
Available at: https://ir.lawnet.fordham.edu/ulj/vol17/iss3/1