[T]he Restatement [(Second) of Torts § 491 comment c] . . . define[s] the four elements of a joint enterprise as:
- an agreement, express or implied, among the members of the group;
- a common purpose to be carried out by the group;
- a community of pecuniary interest in that purpose, among the members; and
- an equal right to a voice in the direction of the enterprise, which gives an equal right of control.