dissenting:
The majority reasons that because Jaime may be collaterally estopped, this is sufficient to uphold the district court’s finding Jaime has an interest in his parents' action which could be impaired if that action goes forward without him as a party. I dissent.
I believe the majority, in adopting the reasoning in Lopez v. Martin Luther King, Jr. Hospital, 97 F.R.D. 24 (C.D.Cal.1983), has put the cart before the horse. In Lopez, the district court stated what was believed to be the relevant inquiry as follows: “[I]f there is a possibility that collateral estoppel will be applied by the California court, then it is axiomatic that the child has an interest in this action.” 97 F.R.D. at 30.
The majority in this case employed this exact reasoning, finding that this “interest” determination is properly construed “ ‘from a practical perspective, not through the adoption of strict legal definitions and technicalities.’ ” (Opinion at p. 182, citing Lopez v. Martin Luther King, Jr. Hospital, 97 F.R.D. at 29).
While the question of joinder is one of federal procedure, in diversity cases the *1095standards must be applied to the rights and interests that are derived from and defined by state law. Provident Tradesmens Bank & Trust Co. v. Patterson, 390 U.S. 102, 125 n. 22, 88 S.Ct. 733, 746 n. 22, 19 L.Ed.2d 936 (1968). In this case, section 376 of the California Code of Civil Procedure provides the Aguilars with a separate and independent cause of action from that asserted by Jaime in state court. Faitz v. Ruegg, 114 Cal.App.3d 967, 971, 171 Cal.Rptr. 149, 150 (1981) (right to recover for loss of child’s earnings and for medical expenses incurred in treating its injuries belongs to parent).
To be sure, Jaime has an obvious financial stake in the outcome of his parents’ action, but this cannot support the legally protected “interest” required to invoke Rule 19(a). See 3A Moore’s Federal Practice II 19.07 — 1[2], at 19-129 (2d ed. 1982). “It is a misapplication of Rule 19(a) to add parties who are neither necessary nor indispensable, who are not essential for just adjudication and who have a separate cause of action entirely.” Bakia v. County of Los Angeles, 687 F.2d 299, 301 (9th Cir. 1982). Thus, the majority has used inverse reasoning to find Jaime’s legally protected “interest” in the instant action from mere speculation that collateral estoppel might be applied in Jaime’s separate state court action.
Even assuming Jaime has the required interest in his parents’ action, Rule 19(a) is satisfied only if the disposition of the action in his absence would either (i) as a practical matter impair or impede his ability to protect that interest, or (ii) leave any of the persons already parties subject to a substantial risk of incurring double, multiple or otherwise inconsistent obligations by reason of his claimed interest.
This court concludes that “[sjince a California court may find Jaime collaterally estopped from pursuing his own suit in state court, the district court here properly found him to have an interest in his parents’ action that could be impaired if that action goes forward without him as a party.” To the contrary, I agree with both the holding and reasoning of Judge Cynthia Holcomb Hall’s decision in Cortez v. County of Los Angeles, 96 F.R.D. 427 (C.D.Cal. 1983). Like Lopez, the facts in Cortez were identical to those present here. Judge Hall found the minor child in that case “could not be collaterally estopped by his parents’ litigation of their distinct legal right to recovery.” 96 F.R.D. at 429.
Here, the application of Rule 19 requires inquiry into the effect on Jaime of any relief granted to his parents, and whether “as a practical matter” such may “impair or impede his ability to protect his interest.”
The language “as a practical matter” has a restrictive as well as an expansive side. Thus, the fact that the absent person may be bound by the judgment does not of itself require his joinder if his interests are fully represented by parties present, and the mere theoretical possibility of prejudice does not require join-der.
3A Moore’s Federal Practice, ¶ 19.07-1[2-1], at 19-133 (2d ed. 1982) (footnotes omitted). As pointed out by Judge Hall, these parents, like those in Cortez, have every incentive to reach a result that will benefit their child’s legal interest as well as their own. This is not a case where one party may do something to affect wrongfully the rights of a nonparty. All inferences point to the fact that these parents will vigorously do all they can to protect their child and make every argument Jaime would or could make if he were a party. Indeed, Rosa Aguilar is the appointed guardian ad litem in Jaime’s state court action, charged with the responsibility to litigate that case in Jaime’s best interests. To presume Jaime’s interest will be prejudiced if this action is allowed to proceed without him as a party flies in the face of common sense and recognized familial bonds.
In applying Rule 19 “courts must refrain from taking a view either too broad or too narrow in determining ‘prejudicial’ effect of a judgment. The watchwords of Rule 19 are ‘pragmatism’ and ‘practicality.’ ” Schutten v. Shell Oil Co., 421 F.2d 869, *1096874 (5th Cir.1970). “Rather the courts are urged to consider whether the absentee would be ‘adversely affected in a practical sense, and if so, would the prejudice be immediate and serious, or remote and minor?’ ” Gottlieb v. Vaicek, 69 F.R.D. 672, 675 (N.D.Ill.1975), aff'd, 544 F.2d 523 (7th Cir.1976).
The second prong of the Rule 19(a) inquiry would require Jaime’s joinder if his absence would leave any of the parties subject to a substantial risk of incurring double, multiple or otherwise inconsistent obligations. Following the reasoning of Judge Hall in Cortez and as set forth above, there is no risk of double or multiple liability to defendants in this case because Jaime’s parents claim damages under their independent cause of action established by section 376 of the California Code of Civil Procedure. Thus, I conclude Jaime is not a person who should be joined in this action and, therefore, an analysis of whether the equities of the case require dismissal pursuant to Rule 19(b) is unnecessary.
I would adopt the decision of Judge Hall in Cortez v. County of Los Angeles, 96 F.R.D. 427 (C.D.Cal.1983), and reverse the district court and remand for further proceedings.