¶ 1 The issue for decision is whether an agreement by the City of Phoenix to pay a developer as much as $97.4 million for the use of garage parking spaces violates the Gift Clause, Ariz. Const, art. 9, § 7. Although we conclude that the agreement quite likely violates the Gift Clause, because language in our previous opinions could well have led the City to conclude that the agreement was constitutional, we today clarify our Gift Clause jurisprudence and apply bur decision prospectively only.
I.
A.
¶2 CityNorth is the proposed commercial core of Desert Ridge, a Phoenix master-planned community. CityNorth is projected to contain office space, luxury hotels, residences, several parking garages, and more than one million square feet of high-end retail space.
¶ 3 CityNorth’s developer, NPP CityNorth L.L.C. (“NPP”), approached the City of Phoenix, claiming it could not complete the project as planned without financial assistance. The City became concerned that absent such aid, the development might not contain the full proposed retail component and potential sales tax revenues would be lost, perhaps to neighboring Scottsdale.
¶ 4 In response to NPP’s request, the City Council adopted Ordinance No. S-33743, which authorized the City to enter into a “Parking Space Development and Use Agreement” (the “Parking Agreement”) with NPP. The Ordinance contained findings, as required by AR.S. § 9-500.11(D) (2008), that tax revenue generated by the CityNorth project would exceed the amount to be paid to NPP under the Agreement and that without a tax incentive, the project would not locate in the City in the same time, place, or manner. The Ordinance provided, as required by § 9-500.11(H), that the City not enter into the Parking Agreement until these findings were independently verified.
B.
¶ 6 In August 2007, Meyer Turken and several other Phoenix taxpayers and business owners (collectively, “Turken”) sued the City to enjoin payments to NPP under the Parking Agreement. Turken alleged that the Agreement violated the Gift Clause, which provides:
Neither the state, nor any county, city, town, municipality, or other subdivision of the state shall ever give or loan its credit in the aid of, or make any donation or grant, by subsidy or otherwise, to any individual, association, or corporation, or become a subscriber to, or a shareholder in, any company or corporation, or become a joint owner with any person, company, or corporation____
Ariz. Const, art. 9, § 7. Turken also alleged that the Parking Agreement violated the Equal Privileges and Immunities Clause, Ariz. Const, art. 2, § 13, and the Special Laws Clause, Ariz. Const, art. 4, pt. 2, § 19.
¶ 7 The superior court granted summary judgment to the defendants. In rejecting Turken’s Gift Clause arguments, the court relied upon the two-pronged test set forth in
Wistuber v. Paradise Valley Unified School District,
¶ 8 The court of appeals reversed.
Turken v. Gordon,
¶ 9 The City and NPP petitioned for review. We granted review because interpretation of the Gift Clause is an issue of statewide importance. We have jurisdiction under Article 6, Section 5, Clause 3, of the Arizona Constitution and A.R.S. § 12-120.24 (2003).
II.
A.
¶ 10 The records of Arizona’s constitutional convention provide little guidance in interpreting the Gift Clause.
See
John S. Goff,
The Records of the Arizona Constitutional
[The Gift Clause] represents the reaction of public opinion to the orgies of extravagant dissipation of public funds by counties, townships, cities, and towns in aid of the construction of railways, canals, and other like undertakings during the half century preceding 1880, and it was designed primarily to prevent the use of public funds raised by general taxation in aid of enterprises apparently devoted to quasi public purposes, but actually engaged in private business.
Day v. Buckeye Water Conservation & Drainage Dist.,
¶ 11 Early Gift Clause challenges often also attacked public expenditures under Article 9, Section 1 of the Arizona Constitution (the “Tax Clause”), which requires that “all taxes ... shall be levied and collected for public purposes only.”
See, e.g., Proctor v. Hunt,
¶ 12 Our cases interpreting the Gift and Tax Clauses have struggled to define “public purpose.” In a seminal Tax Clause case, we noted that “[p]ublie purpose is a phrase perhaps incapable of definition, and better elucidated by examples.”
City of Tombstone v. Macia,
¶ 13 Our Gift Clause jurisprudence has also emphasized that “the term ‘public purpose’ ... changes to meet new developments and conditions of times.”
White,
[i]f it be borne in mind that slum clearance projects are means adopted by society for self-protection against crime and disease, and that money spent to prevent or eradicate these enemies is for the public good and general welfare, even though the effect is felt by a given class more than by the community at large, it will be realized the sums spent are not a gift or loan to anyone but an expenditure in the interests of the general public.
Humphrey v. City of Phoenix,
¶ 14 Our cases also emphasize that although determining whether governmental expenditures serve a public purpose is ultimately the province of the judiciary, courts owe significant deference to the judgments of elected officials. For example, we noted in
White
that the city council “should have some latitude” in determining whether membership in the Arizona Municipal League would
B.
¶ 15 Montana courts had concluded by the early 1970’s that a public purpose alone satisfied their Gift Clause.
See, e.g., Fickes v. Missoula County,
¶ 16 This approach, however, threatened to reduce the Gift Clause to something of a redundancy, because the Tax Clause proscribes use of tax revenues for anything but a public purpose. 3 Moreover, reliance on public pui’pose alone left open the possibility that government payments made under a contract, even if for a public purpose, might so greatly exceed the consideration received in return as to amount to a subsidy to a private entity. For example, a city’s purchase of a garbage truck would undoubtedly serve a public purpose. Purchasing the truck for twenty times its fair value, however, would constitute a subsidy to the seller.
¶ 17 A second panel of the court of appeals rejected the
Heiner
approach in
City of Tempe v. Pilot Properties, Inc.,
¶ 18
Wistuber
resolved the conflict between
Heiner
and
Pilot Properties. Wistuber
involved an agreement by a school district to relieve the president of the teachers’ union from classroom responsibilities while continuing to pay a portion of her salary.
C.
¶ 19 The opinion below concluded that
“Wistuber
did not adopt [a] definitive two-prong test.”
Turken,
¶ 20 Although the language quoted from
Kromko
reflects a core Gift Clause principle, that case did not modify the
Wistuber
test. The language originated from
Walled Lake Door,
¶ 21 In focusing on whether a public expenditure “unduly promot[es] private interests,” the opinion below effectively adopted Justice Cameron’s
Wistuber
dissent, which proposed a “primary/ineidental benefit” Gift Clause test, forbidding transactions in which the private entity is the primary beneficiary.
Wistuber,
¶ 22 We adhere to that straightforward approach today. When a public entity purchases something from a private entity, the most objective and reliable way to determine whether the private party has received a forbidden subsidy is to compare the public expenditure to what the government receives under the contract. 4 When government payment is grossly disproportionate to what is received in return, the payment violates the Gift Clause. We therefore analyze whether the Parking Agreement violates the Gift Clause under the two-pronged Wistuber test.
III.
A.
¶ 23 No party questions that payments by the City under the Parking Agreement would serve a public purpose. The parties agree that providing parking is a legitimate public purpose and that the City could have erected a parking structure of its own without violating the Gift Clause.
See Walled Lake Door,
¶ 24 The City contends that the Parking Agreement also serves several indmect public purposes. It argues that because NPP may have been unable to complete its planned retail component absent the Agreement, the transaction will serve to increase the City’s tax base. The City also asserts that the Agreement will produce denser development, decreased pollution, and employment opportunities for city residents.
¶ 25 While conceding that these goals were “legitimate purposes for the City to pursue,” the court of appeals questioned whether such “indirect” benefits, no matter how substantial, can suffice to establish that the Parking
¶26 In
White,
for example, we found a public purpose for a municipality’s expenditure to join the Arizona Municipal League, deeming it a “reasonable effort to learn the manner in which complex municipal problems ... are being solved in sister cities of the state, thereby improving the quality of service [Glendale] renders its own taxpayers.”
¶ 27 Other decisions are to the same effect.
Industrial Development Authority of Pinal County
involved an attack under the Gift Clause on a public agency’s issuance of bonds, the proceeds of which were loaned to a copper company to purchase and install air pollution control facilities.
¶ 28 In taking a broad view of permissible public purposes under the Gift Clause, we have repeatedly emphasized that the primary determination of whether a specific purpose constitutes a “public purpose” is assigned to the political branches of government, which are directly accountable to the public.
See, e.g., Wistuber,
¶ 29 In this case, we cannot conclude that the City Council “unquestionably abused” its discretion in determining that the Parking Agreement had a public purpose. The Agreement thus satisfies the first prong of the Wistuber test. 5
B.
¶30 When public funds are used to purchase something from a private entity, finding a public purpose only begins the constitutional inquiry.
Wistuber
also requires us to examine the “consideration” received from the private entity. The Gift Clause is violated when that consideration, compared to the expenditure, is “so inequitable and unreasonable that it amounts to an abuse of discretion, thus providing a subsidy to the private entity.”
Wistuber,
¶ 31 The term “consideration” has a settled meaning in contract law. It is a “performance or return promise” that is “bargained for ... in exchange for the promise of the other party.”
Schade v. Diethrich,
¶ 32 Under contract law, courts do not ordinarily examine the proportionality of consideration between parties contracting at arm’s length, leaving such issues to the marketplace.
See, e.g., Sun World Corp. v. City
¶ 33 In finding that the Parking Agreement satisfied the
Wistuber
test, the superior court viewed the relevant consideration as not only the value of the parking places obtained by the City, but also indirect benefits, such as projected sales tax revenue. The court erred in that analysis. Although anticipated indirect benefits may well be relevant in evaluating whether spending serves a public purpose, when not bargained for as part of the contracting party’s promised performance, such benefits are not consideration under contract law,
Schade,
¶34 A hypothetical illustrates the point. Assume that a municipality must repair a sewer line. If the line is not repaired, disease will likely break out and spread quickly, causing deaths and significant public health care expenditures. Several competent contractors are willing to do the repair for $5,000. Under the City’s reasoning, the municipality could pay a contractor $5 million without violating the Gift Clause because the indirect benefits from the repair — saved lives and avoided health care costs — exceed the $5 million payment.
¶35 We disagree that this should be the result. The Gift Clause prohibits subsidies to private entities, and paying far more than the fair market value for the repair plainly would be a subsidy to the contractor. Similarly, if the City’s payments to NPP under the Parking Agreement are grossly disproportionate to the objective value of what NPP has promised to provide in return, the consideration prong of the Wistuber test has not been satisfied.
1.
¶ 36 We therefore turn to the consideration provided for in the Parking Agreement. The Agreement is clear — the City has agreed to pay up to $97.4 million for the non-exclusive use of some 2,980 parking garage spaces and the exclusive use of 200 park-and-ride spaces. NPP made no other promises.
¶37 To be sure, the City’s obligation to make payments under the Agreement does not commence until NPP has developed a specified amount of retail space. However, the Agreement makes plain that NPP has no contractual obligation to build the retail component, characterizing retail construction as “a condition precedent of the City’s obligation to pay the Use Payment and not a covenant of the Developer.”
¶38 As the City notes, the payments for the parking spaces under the Agreement are based on the taxes generated at the development. But the Agreement does not obligate NPP to produce a penny of tax revenue for the City. Rather, the duty of CityNorth and its tenants to pay taxes arises from law applicable to all, not out of contract.
¶ 39 In short, the only consideration flowing to the City from NPP under the Parking Agreement is the right to use the parking spaces. Under Wistuber, the relevant inquiry is whether the amount the City has agreed to pay for use of those spaces is grossly disproportionate to what it will receive.
2.
¶ 40 The Parking Agreement obligates the City to pay up to $97.4 million for the parking spaces. The City argues that its payments cannot be a gift or subsidy under the Gift Clause, because they will be offset by tax revenues from the CityNorth project. But this argument misses the point. Once collected, these tax revenues are public funds. Whether the subsequent expenditure of those funds is consistent with the Gift
¶41 The City and NPP also argue that compliance with A.R.S. § 9-500.11, which requires that anticipated tax revenues exceed any tax incentives, establishes compliance with the Gift Clause. Of course, as the court of appeals noted, statutory compliance does not automatically establish constitutional compliance.
Turken,
3.
¶ 42 Thus, the remaining question is whether the $97.4 million that the City has promised to pay far exceeds the value of the parking places promised in return. Turken has conceded that $97.4 million might well be a fair payment for exclusive use of 3,180 spaces over the next 45 years. The Parking Agreement, however, gives the City exclusive use of only 200 spaces. Nothing in the Agreement prevents CityNorth customers from filling up the other 2,980 spaces when other members of the public might most want to use them.
¶ 43 We find it difficult to believe that the 3,180 parking places have a value anywhere near the payment potentially required under the Agreement. The Agreement therefore quite likely violates the Gift Clause. However, because the superior court viewed projected sales tax revenue and other indirect benefits as consideration for Wistuber purposes, it never separately addressed the value of the parking places. We are not finders of fact, and our intuitions as to proportionality, however strong, cannot substitute for specific findings of fact. Thus, under normal circumstances, we would be constrained to remand to the superior court.
4.
¶ 44 A remand, however, is not necessary in this case. Although “[normally our decisions in civil eases operate retroactively as well as prospectively,”
Lowing v. Allstate Ins. Co.,
¶ 45 We today overrule no prior decision. But we recognize that the consideration prong of the Wistuber test has been widely misunderstood during the past two decades and that our cases have never squarely addressed that issue. The able trial judge believed that indirect benefits satisfied the Wistuber consideration prong and no party appeal's to have directly argued to the contrary below. Moreover, various amici have claimed that a number of public-private transactions were entered into since Wistuber under a similar misapprehension.
¶ 46 To some extent, this confusion may have arisen from our statement in
Wistuber
that “[t]he public
benefit
to be obtained from the private entity as consideration for the payment or conveyance by a public body may constitute a ‘valuable consideration.’ ”
¶ 47 Confusion may also have been caused by the statement in
Wistuber
that a “panoptic view of the facts of each transaction is required.”
Id.
at 349,
¶ 48 The confusion may have been exacerbated by the statement in
Kromko
that “perpetuation of the critical educational relationship between the hospital and the University of Arizona College of Medicine” can be counted as consideration.
¶49 In short, although neither Wistuber nor Kromko held that indirect benefits enjoyed by a public agency as a result of buying something from a private entity constitute consideration, we understand how that notion might have been mistakenly inferred from language in our opinions. We therefore believe it appropriate to limit today’s clarification of the consideration test to transactions occurring after the date of this opinion.
IV.
¶ 50 For the reasons above, we vacate the opinion of the court of appeals. Because we apply our clarification of the Wistuber consideration test prospectively, we affirm the superior court’s dismissal of Turken’s Gift Clause claim. 7 The court of appeals did not reach Turken’s other constitutional arguments, and we therefore remand to the court of appeals to consider those issues in the first instance.
Notes
. The taxes specified in the Parking Agreement are "construction transaction privilege taxes” and taxes "directly related to the business activities of amusement, commercial property rental, hotels and motels, job printing, publishing, rental of tangible personal property, residential property rental, restaurants and bars, retail sales, and use taxes.”
. The court of appeals did not reach Turken’s other constitutional arguments.
Turken,
. Because the Montana courts had construed that state’s gift clause to permit any expenditures made for a public purpose, the framers of the revised Montana Constitution omitted the clause as unnecessary in light of other constitutional provisions limiting public expenditures to public purposes. Montana Legislature, Montana Constitutional Convention 1971-1972, at 583 (1979), available at http://mont anacourts.org/content/library/mt_cons_convention/vol2.pdf.
. Wistuber did not, nor do we today, deal with non-contractual public expenditures, such as direct assistance to the needy. In such circumstances, the private party does not promise to do anything in return, and there thus is no occasion to analyze adequacy of consideration.
. As the court of appeals correctly noted, the Gift Clause public purpose requirement differs from the mandate under Article 2, Section 17 of the Arizona Constitution that private property be taken only for "public use” through eminent domain.
Turken,
. Recent legislation bans municipal tax incentives for relocating retail businesses in certain metropolitan areas, including Maricopa County. A.R.S. § 42-6010 (Supp.2008).
. Turken's supplemental brief sought attorneys’ fees in this Court. But, even assuming
arguendo
that Turken was the prevailing party,
cf. Wagenseller v. Scottsdale Mem’l Hosp.,
