California Code of Civil Procedure Section 389 Interpretation
Code of Civil Procedure section 389 "first sets out, in subdivision (a), a definition of persons who ought to be joined if possible (sometimes referred to as 'necessary' parties).
Then, subdivision (b) sets forth the factors to follow if such a person cannot be made a party in order to determine 'whether in equity and good conscience the action should proceed among the parties before it, or should be dismissed without prejudice, the absent person being thus regarded as indispensable.' . . . the subdivision (b) factors 'are not arranged in a hierarchical order, and no factor is determinative or necessarily more important than another.'(County of San Joaquin v. State Water Resources Control Bd. (1997), 54 Cal. App. 4th at p. 1149, italics omitted.)
The language of Code of Civil Procedure section 389, subdivision (b), "refers to a determination 'in equity and good conscience.' . . . It makes no sense to grant the trial court an expressly discretionary power to balance the equities, then reject the court's evaluation out of hand and balance the equities anew." (County of San Joaquin v. State Water Resources Control Bd., supra, 54 Cal. App. 4th at p. 1151.)
Thus, "section 389, subdivision (b), leaves the trial court 'with substantial discretion in considering which factors to weigh and how heavily to emphasize certain considerations in deciding whether the action should go forward in the absence of someone needed for a complete adjudication of the dispute." ( Id., at p. 1154.)