OPINION
In this appeal we must determine whether the Department of Revenue (DOR) correctly denied Union Oil Company of California’s (hereinafter Union) request for a partial refund for tax years 1973 and 1974. Union calculates its tax liability using for-mulary apportionment instead of separate accounting. The DOR ruled Union’s claim barred by res judicata. The DOR, however, decided Union’s claim on the merits as well, ruling against Union's formulary accounting method. The superior court, sitting as an appellate court, affirmed the DOR’s ruling on the merits, but did not address the issue of res judicata. We do likewise in this appeal.
I
This case is related to
Union Oil Co. of California v. State, Dep’t of Revenue,
677
*63
P.2d 1256 (Alaska 1984)
(Union I).
To understand the present litigation, it is necessary to briefly set forth our analysis in
Union
I:
1
Union protested the DOR’s finding of a tax deficiency relating to Union’s application of a tax-exemption Certificate granted to a Union subsidiary, Collier Carbon & Chemical (hereinafter Collier).
2
Union I,
In other words, Collier’s exemption was calculated using separate accounting to determine the amount of the credit. This credit was then applied to the actual tax liability of Collier under formulary apportionment. Thus, the tax deficiency for thе tax years 1973 through 1977 was upheld, and Union’s tax liability was assessed at $3,544,106 plus interest. Id. at 1259.
Subsequently, Union paid the tax, but protested part of the assessment and requested a refund. Union claimed $47,-612.50 for 1973 and $187,847 for 1974 as determined by formulary apportionment. In June 1984 the DOR informed Union that this court’s decision in Union I precluded Union’s request for a refund, asserting that the tax liability for the years 1973 and 1974 had already been litigated and, therefore, Union’s claim was barred by res judi-cata. In February 1985 Union filed suit against the state for the refund plus interest, claiming that the industrial development income of the exempt business, Collier, should be credited by the disрuted amounts under the formulary apportionment method.
In August 1985 the parties stipulated to a stay of the proceedings in superior court, to allow the DOR time to conduct an administrative review. An informal conference took place on November 8, 1985, and the results of that conference were adopted as the final administrative decision of the DOR.
In December 1986, in Revenue Decision 86-A-l, the DOR ruled Union’s tax refund claims barred by res judicata. Alternatively, it concluded on the merits that for-mulary apportionment was improper for ascertaining the amount of Collier’s industrial tax crеdit and that the separate accounting method was appropriate. In February 1988 Union appealed the revenue de- *64 cisión to the superior court, claiming, inter alia, that “[t]he [DOR] erred in determining that consideration [of the tax refund claims] was barred by the doctrine of res judicata.” Union also claimed the DOR decision was wrоng with respect to the proper accounting method, was not supported by the record and was “arbitrary and capricious.”
In April 1989 the superior court affirmed the DOR decision as to the method of accounting. The superior court also concluded that the state was not judicially es-topped from arguing an opposing contention than one forwarded in prior litigation. Union now appeals the trial court’s affirmance of the DOR decision.
II
A. The Appropriate Standard of Review
The parties disagree, in part, concerning the appropriate standard of review. Union argues that all issues before the court may be resolved by the exercise of this court’s independent judgment. The DOR agrees that this court may exercise its independent judgment relative to the DOR’s legal conclusion, i.e., res judicata, but that a reasonable basis test applies with respect to the DOR’s interpretation of tax statutes and tax policy.
In
Gulf Oil Corp. v. State, Dep’t of Revenue,
The reasonable basis test is applied in either of two situations:
First, ... where the agency is making law by creating standards to be used in evaluating the case before it and future cases. Second, ... when a case requires resolution of policy questions which lie within the agency’s area of expertise and are inseparable from the facts underlying the agency’s decision.
Id.
(quoting
Earth Resources v. State, Dep’t of Revenue,
In
Union I,
we applied the reasonable basis test with regard to the DOR’s interpretation of the exemption Certificate.
Union I,
We grant no deference to the superior court’s decision when the superior court acts as an intermediate court of appeal.
Tesoro,
*65 B. The DOR’s Decision To Impose Formulary Apportionment
Alaska Statute 43.25.040
5
deems the Exemption Certificate between Collier and the state a contract. As discussed in
Union I,
however, because tax exemption contracts are “in derogation of the sovereign authority and of common right,”
6
the Certificate is to be construed strictly against the exemption.
Union I,
The DOR concluded, and the superior court agreed, that an exempt business under the Alaska Industrial Incentive Act, AS 43.25, is exempt from tax based “only upon its industrial development income,” which is defined by statute, AS 43.25.150(а)(7), as that income derived from property devoted to industrial development. The DOR concluded that the intent of the exemption was to focus on the source of the income, which is better done by separate accounting. The DOR’s decision stated:
Thus, the difference between separate accounting and formulary apportionment is that the formula method does not attempt to identify the precise geographical source of income. Separate accounting looks to the source of income but formulary apportionment looks to activities within a state. It is this distinction between “sources” and “activities” that is important.
The DOR held that the tax exemption figure was properly arrived at under separate accounting in order to determine the amount of the credit, which is then applied to the actual tаx liability of the exempt business under formulary apportionment.
Union argues that the income exemption must be calculated in the identical manner as actual tax liability. We held in Union I that actual tax liability could reasonably be computed by formulary apportionment; thus, Union contends exempt income should, out of fairness, be calculated in the same manner. Union characterizes the state’s use of two methods for two calculations as an attempt by the state to “have [its] cake and eat it too.” Union points out that the state had on previous occasions indicated that separate accounting was not necessarily required in calculating exempt income and credits.
The state posits that the DOR was never presented with this question before its formal revenue decision, 86-A-l. The superi- or court found no inconsistency with the DOR’s pоsition in Union I, Revenue Decision 81-30 and Revenue Decision 86-A-l. The superior court found:
income under [AS] 43.20 is to be determined under the formulary apportionment method but that exempt income under [AS] 43.25 is to be determined under the separate accounting method and that this interpretation is supported by the language and policy of AS 43.30, AS 43.25 and the Certificate.
The state asserts that the calculations involve a “two-step” process, and therefore two approaches are reasonable. Finally, the state argues that (1) separate accounting should be used to determine exempt business income and credits because separate accounting is the only method capable of identifying industrial development income under AS 43.25.010(a), and (2) the Alaska Industrial Incentive Act allows an exempt business to be exempt from income tax on its income derived solely from industrial development.
We affirm the DOR’s interpretation. Union has failed to point out any term or provision in the Certificate indicat
*66
ing that formulary apportionment is appropriate for calculating exempt income. The presumption that the state’s aрplication of the Certificate is reasonable has not been overcome, much less has Union demonstrated that the “contract clearly and unequivocally extends the exemption beyond the state’s interpretation.”
Union I,
Notes
. The litigation between Union I and this case overlaps to such an extent that the parties agreed that the record in this case would be comprised of, among other items, "all items in the administrative record in the prior proceedings before DOR, the entire record from the Superior Court proceedings, and the entire record from the Supreme Court proceedings [in Union /].”
. In 1969 the Commissioner of the Department of Economic Development granted Collier a tax exemption Certificate exempting Collier from, among other taxes, state income taxes.
. Separate accounting takes the gross income of the business and deducts all allowable businеss expenses to arrive at a net taxable income. The net taxable income is multiplied by the applicable tax schedule rate to determine the tax liability. For purposes of the industrial income tax exemption Certificate, the tax liability is deemed a tax credit, zeroing out tax liability.
Under formulary apportionment "[t]he property, payroll and sales fractions ('factors’ under the statute) are averaged and an ‘ideal’ fraction is arrived at which reflects the degree of state connectedness of the business entity's [worldwide] income. Only this fraction of the entire income is then taxed by the state.”
Earth Resources Co. v. State, Dep’t of Revenue,
.Union is the parent corporation for the following wholly-owned subsidiaries: Collier, Woodland Development Company and Union Alaska Pipeline Company. Only Collier was granted the tax credit Certificate. Union files consolidated tax returns for these companies, and the dispute in
Union I
centered on offsetting the tax credits allowed to Collier with the tax liability of the other, non-exempt corporations.
Union I,
. AS 43.25.040 provides in part:
A grant of tax exemption under this chapter is considered a contract between the grantee and the state.
. See 71 AmJur.2d State and Local Taxation § 331, at 642 (1973).
. Union also contends that the state is judicially estopped from asserting its present position, as Union believes the state has taken a contrary position in prior litigation. The doctrine of judicial quasi-estoppel precludes a litigant from taking an inconsistent position from prior litigation where the circumstances of the new position would render the previous position unconscionable.
See Alaska Statebank v. Kirschbaum,
. We note that the state must consistently apply the present methodology; exempt income must be calculated by separate accounting, and actual tax liability must be ascertained under formu-lary apportionment.
