Which of the following is NOT a criterion for a joint venture?

The key characteristic that distinguishes a joint venture is the collaborative nature and the shared control between the parties involved. A joint venture is typically defined by three main criteria: a contractual arrangement that formalizes the partnership, the undertaking of a separate and specific activity to achieve mutual business objectives, and joint control, meaning that all parties have a say in the management and decision-making processes of the venture.

The aspect of having an "explicit, measurable equity interest" is not a standard criterion for defining a joint venture. While participants may indeed have equity interests, the joint venture itself is more concerned with management and operational control rather than the quantification of equity holdings. Thus, this criterion may be relevant to broader discussions of equity and investment but does not define the essence of a joint venture.

In summary, the annual focus on contractual arrangements, defined activities, and joint control over the venture underscores the nature of joint ventures, making the absence of a necessity for a clearly defined equity interest the correct choice in this context.