OPINION OF THE COURT
In this appeal we consider whether the District Court properly applied the doctrine of collateral estoppel to preclude the Pennsylvania Public Utility Commission (the “PUC”) from relitigating its claim to Eleventh Amendment immunity. Because we find that all requirements for application of collateral estoppel are met and no equitable considerations counsel against its application, we will affirm.
I.
This case arises out of proceedings initiated by the Southeastern Pennsylvania Transportation Authority (“SEPTA”) before the PUC. SEPTA petitioned the PUC for the right to construct certain “partial high-level passenger platforms” at fivе passenger stations owned by National Railroad Passenger Corporation (“Amtrak”), along Amtrak’s northeast corridor. Although Amtrak was not a party to the administrative adjudication, Amtrak advised the PUC that in its view the PUC had no jurisdiction over the issues raised by SEPTA because those issues were either preempted by federal law or subject to arbitration. Despite Amtrak’s objection, the PUC administrative law judge adjudicated the matter and issued a recommended decision. On appeal to the full PUC, the Commissioners ordered the ALJ to reopen the proceeding and issued an order joining Amtrak as an indispensable party to the proceeding.
Prior to a scheduled pre-hearing conference on remand to the ALJ, Amtrak filed this action against the PUC and the PUC’s five commissioners asserting its federal preemption claims and seeking to compel arbitration. In response, the PUC
In 1987, in the earlier suit, Amtrak secured a permanent injunction, based on the authority of 45 U.S.C. § 546b,
On September 15, 1997, the District Court issued a cоmprehensive memorandum opinion denying the PUC’s motion to dissolve the injunction. After finding that Amtrak is not a federal entity for the purposes of the doctrine of Eleventh Amendment immunity, the District Court considered the question of whether the PUC is an arm of the Commonwealth of Pennsylvania entitled to Eleventh Amendment immunity. See National R.R. Passenger Corp.,
(1) whether, in the event the plaintiff prevails, the payment of the judgment would come from the state (this includes three considerations: whether the payment will come from the state’s treasury, whether the agency has sufficient funds to satisfy the judgment, and whether the sovereign has immunized itself from rеsponsibility for the agency’s debts); (2) the status of the agency under state law (this includes four considerations: how state law treats the agency generally, whether the agency is separately incorporated, whether the agency can sue and be sued in its own right, and whether it is immune from state taxation); and (3) what degree of autonomy the agency enjoys.
Id. at 1144-45.
The District Court found that the first factor, the source of the funds to satisfy any judgment, “weigh[ed] heavily in support of the finding that the [PUC] is not an arm or alter ego of the Commonwealth.” National R.R. Passenger Corp.,
In this case, the District Court held that the PUC was collaterally estopped to relit-igate the issue of whether it was entitled to Eleventh Amendment immunity. Accordingly, it denied the PUC’s motion to dismiss. The PUC timely appealed invoking this Court’s jurisdiction under the collateral order doctrine. See Puerto Rico Aqueduct and Sewer Auth. v. Metcalf & Eddy, Inc.,
II.
In Witkowski v. Welch,
III.
The Restatement (Second) of Judgments articulates the general rule of collateral estoppel, or in its terminology “issue preсlusion,” as follows: “When an issue of fact or law is actually litigated and determined by a valid and final judgment, and the determination is essential to the judgment, the determination is conclusive in a subsequent action between the parties, whether on the same or a different claim.” Restatement (Second) of Judgments § 27 (1980). We have consistently applied this general rule in determining the collateral effect of federal court judgments. In Burlington Northern Railroad Co. v. Hyundai Merchant Marine,
This general rule is subject to a number of equitable exceptions designed to assure that the doctrine is applied in a manner that will serve the twin goals of fairness and efficient use of private and public litigation resources. The equitable factors to -be considered in a particular case depend in part on (1) whether both parties to the subsequent suit were also parties to the first so that there is “mutuality of estoppel,” see Blonder-Tongue Labs., Inc. v. University of Ill. Found.,
1. The Identity of the Issues
The PUC claims that the Eleventh Amendment immunity issue presented to the District Court in 1997 is not identical to the issue in the case at bar because “in the prior proceeding Amtrak[] claim[ed] that the PA PUC was barred from charging any fees to Amtrak pursuant to 49 U.S.C. § 24301(l)...., and in the present proceeding Amtrak[ ] claimfs] that 49 U.S.C. § 29402(j) ... bars the PA PUC from ruling on safety issues involving Amtrak’s property.”
2. Actual Determination of the Relevant Issue
An argument hеading in the PUC’s brief asserts that the “District Court’s decision in [the] previous matter was not ‘final, valid and on the merits.’ ” It does not contend, however, that the 1977 decisions denying the PUC’s application to dissolve the injunction were not final ones or that the District Court lacked subject matter or personal jurisdiction to determine the matter of its own jurisdiction to enter the injunction. It does, however, contend that the District Court did not resolve the Eleventh Amendment issue in 1997 “on the merits” — its way of saying that this issue was not, in Restatement terminology, “actually determined.”
The sole case cited in support of this argument by the PUC is Frazier v. Southeastern Pennsylvania Transportation Authority,
The decision in Frazier is inapposite. Here there is no question that the District Court reached and determined the Eleventh Amendment issue in the 1997 proceeding. The District Court carefully considered and weighed each of the Christy factors in order to determine whether the PUC was entitled to Eleventh Amendment immunity and unambiguously determined that it was not.
3. Essential to the Judgment
The Restаtement (Second) of Judgments explains in the following terms the rationale behind the requirement that the initial resolution of the relevant issue be essential to the judgment:
[I]f issues are determined but the judgment is not dependent upon the determinations, relitigation of those issues in a subsequent action between the parties is not precluded. Such determinations have the characteristics of dicta, and may not ordinarily be the subject of an appeal by the party against whom they were made. In these circumstances, the interest in providing an opportunity for a considered determination, which if adverse may be the subject of an apрeal, outweighs the interest in avoiding the burden of relitigation.
Restatement (Second) of Judgments § 27, cmt. h; see also O’Leary v. Liberty Mut. Ins. Co.,
Thus, in determining whether the issue was essential to the judgment, we must look to whether the issue “was critical to the judgment or merely dicta.” O’Leary,
4. Same Parties
Only the PUC as an entity and not the commissioners were parties to the 1997 proceeding. The PUC, therefore, contends that collateral еstoppel was improperly applied to the commissioners in this proceeding. This contention ignores the fact that the commissioners in their official capacity comprise the PUC and did participate in the 1997 decision. Accordingly, it was entirely appropriate for the District Court to apply collateral estoppel against them to the extent they rely upon their official status to support a claim of Eleventh Amendment immunity.
5. Equitable Concerns
Even when the requirements of the general rule of collateral estoppel are satisfied, the Court must consider whether there are special circumstances present which make it inequitable or inappropriate to foreclose relitigation of a previously determined issue. PUC contends that such special circumstances are present here. Specifically, it contends that relit-igation is warranted (1) because the Eleventh Amendment immunity issue is an “unmixed question of law” and this suit involves a matter “unrelated” to that involved in the prior proceeding and (2) because relitigation is required “in order to take into account intervening change in the applicable legal context or otherwise to avoid inequitable administration of the laws.” Appellants’ Brief pp. 32, 35 (quoting from Restatement (Second) of Judgments § 28(2)).
A. Unmixed Question of Law
In United States v. Moser,
The contention of the Government seems to be that the doctrine of res judicata does not apply to questions of law; and, in a sense, that is true. It does not apply to unmixed questions of law. Where, for example, a court in deciding a case has enunciated a rule of law, the parties in a subsequent action upon a different demand are not es-topped from insisting that the law is otherwise, merely because the parties are the same in both cases. But a fact, question or right distinctly adjudged in the original action cannot be disputed in a subsequent action, even though the determination was reached upon an erroneous view or by an erroneous application of the law.
Id. at 242,
The Supreme Court last considered the Moser “unmixed question of law” exception to the general rule of issue preclusion in United States v. Stauffer Chemical Co.,
The exception seems to require a determination as to whether an “issue of fact” or an “issue of law” is sought to be relitigated and then a determination as to whether the “issue of law” arises in a successive case that is so unrelated to the prior case that relitigation of the issue is warranted. Yet we agree that, for the purpose of determining when to apply an estoppel, “[w]hen the claims in two separate actions between the sаme parties are the same or are closely related ... it is not ordinarily necessary to characterize an issue as one of fact or of law for purposes of issue preclusion.... In such a case, it is unfair to the winning party and an unnecessary burden on the courts to allow repeated litigation of the same issue in what is essentially the same controversy, even if the issue is regarded as one of ‘law’.”
Id. at 171,
More recently, we, too, recognized the continuing vitality of the “unmixed question of law” exception while acknowledging that its scope remains uncertain. Burlington N.R.R.Co.,
While, as Burlington points out, the contractual limitations provisions in this case provides for a shorter period of time (nine months as opposed to one year), and applies to the presentation of “claims” as compared to the filing of “suits,” these distinctions are of no legal significance to the issue decided in Atlantic Mutual and presented here. In both cases Burlington denied the indemnity claims on the grounds that they were untimely because the contract term limited liability to a period of time (commencing at the date of delivery) that had already run. Similarly, in both actions, the indemnity claimant sought recovery notwithstanding such provision on the grounds that any time limit for indemnity claims must commence when liability is determined or a cognizable loss is incurred. In sum, given these relevant similarities, we cannot conclude that the issue of law arising in this action is so unrelated to the Atlantic Mutual case*530 that relitigation of the issue is warranted.
Id. at 1237-38.
As our review of Moser, Stauffer and Burlington indicates, the “unmixed question of law” exception is not easily summarized. It is an equitable doctrine which, while recognizing that the court and the adverse party should ordinarily be spared the burden of relitigating an issue previously determined, nevertheless sounds a note of caution where the issue involved is the choice or formulation of the governing rule of law. Where the same legal issue is presented in two suits but the second suit calls for application of the previously selected rule of law in a significantly different context, it may be inappropriate to preclude a party from contending that the governing rule of law applied in the first was erroneously chosen or formulated. It is not necessary, however, that the “two cases ... must arise from the very same facts or transaction before an estoppel can be applied.” Stauffer Chem. Co.,
Whether the context in which the legal issue is presented in the second suit is sufficiently unrelated to that in the first to counsel against preclusion is a decision that should be made with reference to the consequences of preclusions for the precluded party and the administration of justice. A significantly different context, for example, may make it more likely that the second suit and the stake there at issue were not foreseen at the time of the first suit. Moreover, insistence on estoppel in a new context may in some situations unduly impede the development of the law. Such insistence may also impose an unfair competitive disadvantage on the party who is precluded from rearguing questions of law that would be open to challenge by other litigants. Finally, when the party to be precluded is a public agency responsible for administration of a governmental program, preclusion may impair its ability to regulate in a coherent manner. See 18 Charles Alan Wright, Arthur R. Miller & Edward H. Cooper, Federal Practice and Procedure § 4425, at 244 (1981).
The District Court did not foreclose the PUC from challenging a legal precept. The PUC never sought to argue that Christy v. Pennsylvania Turnpike Authority did not provide the appropriate legal standard. Rather, it sought to argue that the District Court had erroneously applied that standard to the particular circumstances of the PUC at the time of the first suit at least in part because it did not have sufficient information about those particular circumstances. In support of its request for relitigation, the PUC submitted evidence of its particular circumstances which supplemented its submission-in 1997. It did not, however, submit any evidence that its circumstances had changed since that time. The fact that the PUC may not have submitted all of the relevant evidence available to it in 1997, hardly justifies placing on Amtrak the burden of relitigating the application of the Christy legal principles to the unchanged circumstances of the PUC.
Moreover, while it is true that the two relevant proceedings here present distinct preemption issues, the issue as to which estoppel is sought does not arise in such a different context that the current situation implicates any of the concerns underlying the “unmixed question of law” doctrine. Amtrak and the PUC undoubtedly foresaw in 1997 that there would be repeated is
For these reasons, we decline to apply the “unmixed question оf law” exception to the general rule of issue preclusion.
B. Intervening Change in the Legal Context and Avoidance of Inequitable Administration of the Law.
Under this argument heading, the PUC contends that the estoppel applied by the District Court is inequitable because (1) the PUC’s Eleventh Amendment immunity has been previously recognized in other suits, (2) the PUC here tenders evidence not considered in the first proceeding, (3) the PUC had “no expectation that [the] determination [in the first proceeding] would forever bar its claim of sovereign immunity,” and (4) estoppel here might “expose[it] to application of offensive non-mutual collateral estoppel.”
None of the authorities cited by the PUC hold that it is entitled to Eleventh Amendment immunity.
We believe that we have earlier explicitly or implicitly rejected each of the remaining contentions. The ability of the PUC to litigate its Eleventh Amendment immunity with parties other than Amtrak presents a materially different issue. See
We perceive no inequity in the application of collateral estoppel in the context of this case.
IV. Conclusion
The judgment of the District Court will be affirmed.
Notes
. Except where it is relevant to distinguish between them, we will refer to the PUC and the individual commissioners collectively as the "PUC.”
. 45 U.S.C. § 546b was passed on September 10, 1982, Pub.L. 97-257, § 107. At the time of the earlier suit the statute provided:
§ 546b. Exemption from taxes or other fees imposed by any State, political subdivision, or local taxing authority levied on the Corporation or any railroad subsidiary; covered period; jurisdiction to enforce exemption
Notwithstanding any other provision of law, the National Railroad Passenger Corporation (the "Corporation”) shall be exempt from any taxes or other fees imposed by any State, political subdivision of a State, or local taxing authority which are levied on the Corporatiоn, or any railroad subsidiary thereof, from and after October 1, 1981, including such taxes and fees levied after September 30, 1982: Provided, however, That notwithstanding any provision of law, the Corporation shall not be exempt from any taxes or other fees which it is authorized to pay as of September 10, 1982. Taxes and fees levied on the Corporation or any railroad subsidiary thereof by States, political subdivisions of States, or local taxing authorities with respect to periods beginning prior to October 1, 1981, shall be payable in proportion to the part of the relevant tax period which elapsed prior to such date. Notwithstanding the provision of section 1341 of title 28, the United States district courts shall have original jurisdiction over any civil actions brought by the Corporation to enforce the exemption conferred hereunder and may grant equitable or declaratory relief as requested by the Corporation.
45 U.S.C. § 546b (1988). This section was repealed by § 7(b) of the Act of July 5, 1994, Pub.L. No. 103-272, 108 Stat. 1379, and reenacted with linguistic, but not substantive changes and recodified by § 1(e) of the same act, 108 Stat. 904. See H.R.Rep. No. 103-180 at 1, 3, 4 (1993), reprinted in 1994 U.S.C.C.A.N. 818, 820, 822. The relevant section of the 1994 statute stated:
Exemption from taxes levied after September 30, 1981.
(1) Amtrak or a rail carrier subsidiary of Amtrak is exempt from a tax or fee imposed by a State, a political subdivision of a State, or a local taxing authority and leviеd on it after September 30, 1981. However, Amtrak is not exempt under this subsection from a tax or fee that it was required to pay as of September 10, 1982.
(2) The district courts of the United States have original jurisdiction over a civil action Amtrak brings to enforce this subsection and may grant equitable or declaratory relief required by Amtrak.
49 U.S.C. § 24301(l) (1994). That section has since been amended by the Act of December 2, 1997. See Pub.L. 105-134, § 208, 111 Stat. 2584. Throughout the remainder of this opinion we will cite to the statute as § 24301.
. Section 28 provides:
§ 28. Exceptions to the General Rule of Issue Preclusion
Although an issue is actually litigated and determined by a valid and final judgment, and the determination is essential to the judgment, relitigation of the issue in a subsequent action between the parties is nоt precluded in the following circumstances:
(1) The party against whom preclusion is sought could not, as a matter of law, have obtained review of the judgment in the initial action; or
(2) The issue is one of law and (a) the two actions involve claims that are substantially unrelated, or (b) a new determination is warranted in order to take account of an intervening change in the applicable legal context or otherwise to avoid inequitable administration of the laws; or
(3) A new determination of the issue is warranted by differences in the quality or extensiveness of the procedures followed in the two courts or by factors relating to the allocation of jurisdiction between them; or
(4) The party against whom preclusion is sought had a significantly heavier burden of persuasion with respect to the issue in the initial action than in the subsequent action; the burden has shifted to his adversary; or the adversary has a significantly heavier burden than he had in the first action; or
(5) There is a clear and convincing need for a new determination of the issue (a) be*526 cause of the potential adverse impact of the determination on the public interest or the interests of persons not themselves parties in the initial action, (b) because it was not sufficiently foreseeable at the time оf the initial action that the issue would arise in the context of a subsequent action, or (c) because the party sought to be precluded, as a result of the conduct of his adversary or other special circumstances, did not have an adequate opportunity or incentive to obtain a full and fair adjudication in the initial action.
. Both § 24301(l) and § 29402(j) grant Amtrak immunity from the application of certain state and local laws. Section 24301(l) exempts Amtrak from taxes and fees imposed by a State after September 30, 1981. Section 29402(j) exempts Amtrak from state or local building, zoning, subdivision, or other related laws.
. Contrary to the PUC’s insistence, the issue of whether Amtrak was entitled to modification of the injunction is simply unrelated to the issue of whether the District Court's ruling on immunity was essential to the judgment denying relief to the PUC.
. To the extent Amtrak is entitled to proceed against the commissioners in their individual
. See supra, p. 8 n. 3.
. The PUC argues that other courts in the Third Circuit have recognized its Eleventh Amendment immunity and thus the application of collateral estoppel is inappropriate. In making this argument, the PUC relies on three cases from this Court: Bell Atlantic-Pennsylvania, Inc. v. Pennsylvania Public Utility Commission,
In both Bell-Atlantic and MCI, which were consolidated for oral argument on the issue of Eleventh Amendment immunity, we assumed, without deciding, that the PUC was an arm of the Commonwealth. However, we held that under the statutory scheme in question the PUC "knowingly waived its Eleventh Amendment immunity by voluntarily accepting the congressional gift or gratuity of the power to regulate local telecommunications competition under the Act.” MCI Telecommunication Corp.,
. The PUC does not explicitly argue, nor could it persuasively maintain, that there has been an intervening change in the applicable legal context. Undoubtedly the Supreme Court has taken up the issue of Eleventh Amendment immunity with vigor since 1997. See, e.g., Board of Tr. of Univ. of Al. v. Garrett,
