9th Cir. Model Jury Instr. (Civil) 17.9

(17 U.S.C. §§ 101, 201(a))

A copyright owner is entitled to exclude others from copying a joint work. A joint work is a work prepared by two or more authors. At the time of the joint work’s creation, a joint work must have two or more authors, and:

First, each author must have made a substantial and valuable contribution to the work;

Second, each author must have intended that [his] [her] [other pronoun] contribution be merged into inseparable or interdependent parts of a unitary whole;

Third, each author must have contributed material to the joint work which could have been independently copyrighted; and

Fourth, each author must be a person to whom the work owes its origins and who superintended the whole work.

In the absence of an agreement between themselves to the contrary, each author of a joint work shares an undivided interest in the entire joint work. A copyright owner in a joint work may enforce the right to exclude others in an action for copyright infringement.

In deciding whether parties intended their contributions to be merged [in element 2, above], you may consider whether the parties signed a written agreement stating that the copyright in the work is to be jointly owned. If there is no such agreement, you may consider whether:

(a) [both] [each of the] parties exercised control over the work;

(b) [both] [each of the] parties’ actions showed they shared the intent to be co-authors when they were creating the work, for instance by publicly stating that the work was their shared project; and

(c) the audience appeal of the work depends on the contribution of each party so that the share of each party’s contribution to the work’s success cannot be appraised.

In making a substantial and valuable contribution to a work, each author’s contribution to the joint work need not be equal.

A written agreement stating the copyright in the work is to be jointly owned may show that each author of a joint work intended that [his] [her] [other pronoun] contribution be merged into inseparable or interdependent parts of a unitary whole.