Consumers Union of the United States, Inc. (Consumers Union) alleges in this action that regulations, 10 C.F.R. §§ 212.71 — 74, effective January 15, 1974, issued by the Federal Energy Office, now the Federal Energy Administration (FEA), violate § 4 of the Emergency Petroleum Allocation Act of 1973, 15 U.S.C. §§ 751-756 (the Act). Specifically, Consumers Union claims that § 4 of the Act imposes a mandatory duty to establish controls which will ensure “equitable” prices for all domestic crude oil; that FEA, by permitting new and released crude oil to be sold at the free market price violates such statutory duty and has in effect created a massive unauthorized exemption from the Act.
The United States District Court for the District of Columbia denied Consumers Union’s motion for declaratory and injunctive relief and granted FEA’s cross-motion for summary judgment. It held that the Act does not necessitate price ceilings, and that FEA’s decision to let the prices “float” on certain categories of crude oil satisfies the statutory prescription that it specify or prescribe a manner for determining price. The court further ruled that this decision does not result in an invalid exemption from regulation, because all oil remains “subject to” allocation and price controls. Consumers Union has appealed from the decision and order of the district court.
The parties concede that the Act imposes a mandatory duty to “specify” or “determine,” i. e. to “regulate” prices for all crude oil. The Act provides that the President of the United States “. shall promulgate a regulation providing for the mandatory allocation of crude oil, residual fuel oil, and each refined petroleum product, in amounts . . . and at prices specified in (or determined in a manner prescribed by) such regulation.” *1115Section 4(a), in which this requirement is found, also specifies that the implementing regulation “. . . shall apply to all crude oil produced in or imported into the United States,”1 with one exception — “stripper well production,” essentially the output of low-yield properties.2 It is further provided that, “. . .to the maximum extent practicable,” the regulation secure “. [the] preservation of an economically sound and competitive petroleum industry . . . equitable distribution . at equitable prices [and] . minimization of unnecessary
interference with market mechanisms.” § 4(b)(l)(A-I).3
To exempt any category of crude oil from the allocation and pricing system, the President must make specific factual findings which, together with the proposed exemption, shall then be submitted to Congress. The exemption takes effect within a specified period thereafter, provided that neither House meanwhile takes any action expressing its disapproval. Any exemption thereby created may remain valid for a period not in excess of 90 days. § 4(g)(2).4
*1116The regulations in question establish a “two-tier pricing system,” which impose ceilings on certain categories of crude oil while other categories may sell at the market price. Specifically, “old” oil, i. e. oil from properties producing at, or less than, their 1972 levels, cannot be sold at a figure which exceeds the highest posted price for the same grade of crude oil in that particular field on May 15, 1973, plus $1.35. The national average ceiling price for all old crude, which constitutes 60% of domestic production, is approximately $5.35 per barrel.
“New” crude oil, which is the amount of domestic crude oil produced and sold from a property above the amount produced and sold from that property during an equivalent period in 1972, “the base year,” may be sold, under the regulations, without regard to the ceiling price, i. e. at the market price. 10 C.F.R. § 212.74(a). If a particular property did not produce at all during the base year, then all of its current yield is new oil and, accordingly, may be sold at the market price. The prevailing national average price for new oil is approximately $10 per barrel.
“Released” oil constitutes that portion of the output of a particular property producing in excess of its 1972 level which is not “new” oil; that is to say, if the 1972 production level for a particular property is presently exceeded for an equivalent period, the current yield up to the base period production level is labeled “released crude” oil and the balance or excess over that level is “new crude” oil. The maximum allowable price for released oil is the lesser of the current market price or the price derived from a formula made up of the base period production level, the May 15, 1973 posted price, the current market price, and the amount by which present production exceeds base period yield, as delineated in the regulation. 10 C.F.R. § 212.74(b).5
*1117As above stated, the parties differ only in their views of the extent and type of governmental activity which will satisfy the prescription for regulating the prices for all crude oil. The questions presented on appeal for resolution are: (1) does retention of the authority to regulate prices in the future fulfill the statutory mandate or does it create an exemption, which is invalid to the extent that the detailed procedure set out in § 4(g)(2) of the Act has not been followed; (2) if the Act requires more than the mere retention of the authority to regulate prices, does the “regulation,” provided for new and released crude oil, satisfy such additional requirement; and (3) assuming that 10 C.F.R. §§ 212.74(a) and (b) provide a valid form of regulation, does reliance upon the market for the establishment of the price of new and released crude oil satisfy the “equitable” price standard contained in the Act.
The Government argues, and the district court so held, that new and released crude oil have not been exempted from price controls. This court, it is implied, therefore need not decide whether the policy, permitting prices to float to the market level, provides sufficient control to constitute the “regulation” of prices, because FEA has retained the authority to impose more direct controls in the future.
This argument would be valid if the Act merely authorized the regulation of prices when or if the FEA, in its discretion, saw fit to do so, because in such a ease, the failure presently to exercise that authority would not preclude the future imposition of controls. If, however, the Act requires that prices be regulated, any failure so to act, no matter how temporary, exempts present prices from the controls to which they should otherwise be subject.
The Act, by the use of such terms as “shall” and “direct,” imposes a mandatory, non-discretionary duty to specify, or prescribe a method for fixing prices. See, e. g. Escoe v. Zerbst, 295 U.S. 490, 493, 55 S.Ct. 818, 79 L.Ed. 1566 (1935); Richbourg Motor Co. v. United States, 281 U.S. 528, 534, 50 S.Ct. 385, 74 L.Ed. 1016 (1930); National Treasury Employees Union v. Nixon, 492 F.2d 587, 601 (D.C.Cir.1974). Section 2(b), for example, provides that “[t]he purpose of [the] Act is to grant to the President . and direct him to exercise specific temporary authority to deal with shortages of crude oil [This] authority . . shall be exercised for the purpose of minimizing the adverse impacts of [such] shortages.” (Emphasis added.) Section 4(a), moreover, specifies that “the President shall promulgate a regulation providing for the mandatory allocation of crude oil . at prices specified in (or determined in a manner prescribed by) such regulation. . . .” And, § 4(a) further provides that “. . . such regulation shall apply to all crude oil. . . ” (Emphasis added.)
Congress, moreover, by including the specific and comprehensive requirements of § 4(g)(2) has exhibited a clear policy of restricting and closely controlling the grant of exemptions.
This court, in the face of such legislative intent and the clear and unambiguous meaning of the Act, must reject any interpretation of the Act, such as that proffered by appellee, which would permit the Executive, acting through the FEA, to evade a non-discretionary duty and to enlarge the authori*1118ty to create exemptions simply by describing as “subject to controls” that which may simply be determined by the forces of an uncontrolled market.
FEA stresses the fact that the regulations at issue do not in precise terms “exempt” the new and released oil from price controls. This literal approach, adopted by the district court, was rejected by .the Supreme Court in Federal Power Commission v. Texaco, Inc., 417 U.S. 380, 94 S.Ct. 2315, 41 L.Ed.2d 141 (1974). The question is not whether all oil remains “subject to” price controls, but whether the controls mandated by the Act have in fact been imposed. Insofar as FEA has not regulated prices in compliance with the Act, it has created a de facto exemption which is invalid to the extent that the detailed procedures set out in § 4(g)(2) have not been followed.6
While the Act directs that the prices for all categories of crude oil be regulated, it does not specify a particular method for doing so. Consequently FEA has discretion in devising a regulatory scheme, but it cannot adopt measures which contravene a statutory mandate. See, e. g. Permian Basin Rate Cases, 390 U.S. 747, 776-777, 88 S.Ct. 1344, 20 L.Ed.2d 312 (1968); Wisconsin v. Federal Power Commission, 373 U.S. 294, 309, 83 5. Ct. 1266, 10 L.Ed.2d 357 (1963); Federal Power Commission v. Natural Gas Pipeline Co., 315 U.S. 575, 62 S.Ct. 736, 86 L.Ed. 1037 (1942).
We hold that the FEA did not abuse its discretion by promulgating 10 C.F.R. § 212.74(b). Nothing in the language of § 4(a) suggests that prices cannot be prescribed or determined in part with reference to or in relation to market prices. The Act only requires that prices be specified in, or determined in a manner ordained by, the implementing regulation. This requirement is satisfied by a plan calling for a ceiling on prices. See, e. g. Permian Basin Rate Cases, supra, 390 U.S. at 768-790, 88 S.Ct. 1344, 20 L.Ed.2d 312.
The regulation concerning new oil, 10 C.F.R. § 212.74(a), is another matter. The district court held that FEA, by permitting the price to be set exclusively by the operation of the free market, has complied with the Act. New crude oil, however, would sell at the market price even in the absence of such administrative regulation. FEA, therefore, has “permitted” new crude to sell at the market level only in the sense that it has taken no action to compel a different result. If Congress intended that the market could be used as the exclusive regulator of prices, then it could have authorized the President to impose a simple pricing mechanism. Congress, however, has required the promulgation of regulations for all crude oil. And, because Congress will not be presumed to have done a useless, ineffective, or absurd thing, see, e. g. Pennsylvania v. Nelson, 350 U.S. 497, 509-510, 76 S.Ct. 477, 100 L.Ed. 640 (1956), the presumption arises that § 4(a) cannot be satisfied by an administrative scheme which necessarily results in the same price which would prevail in its absence.
The district court concluded that the Act conferred a great deal of discretion upon the President to formulate a pricing mechanism. This derives in part from § 4(b) which requires that the President maximize “to the . . . extent practicable” the various goals set out in that section, many of which conflict with one another. One such goal is the “minimization of economic distortion, inflexibility, and unnecessary interference with *1119market mechanisms.” § 4(b)(l)(I). The trial court relied upon this statement of objectives to support its holding.
Although the President is afforded wide discretion and must attempt to minimize market interference, it was error to conclude that the congressional intent and requirement for affirmative and express regulation of all crude oil could be neutralized in whole or in part and that 10 C.F.R. § 212.74(a) could, therefore, be regarded as a valid implementing regulation. This construction would render superfluous various other mandatory provisions of the Act.7
The Government, on this appeal, does not stand on the theory adopted by the district court. It concedes that the Act requires some form of active interference with the operation of the free market, but it takes the position that the Act has been satisfied because governmental action causes the average price level for all crude oil to vary from that which would prevail under free market conditions. New crude oil, according to the Government, normally constitutes only a portion of the total output of each oil-producing property so that the average of the prices charged by each producer for all his oil is lower than it would be in the absence of the regulations at issue and that therefore FEA has in effect regulated the price for all crude oil.
If this theory were to be adopted, then a simple regulation governing the total amount any one producer could receive for his oil, be it “old,” “new,” “released” or otherwise, would be adequate. But to be permissible, a scheme of indirect regulation must still meet the requirement that the Government affect the price for each category of crude oil and not just that of crude oil taken as a whole. While the provision that FEA specify or prescribe a method for the determination of price does not call for the imposition of price ceilings and can be satisfied by a scheme which affects prices indirectly, we are of the opinion that the ceilings imposed on old and released crude in the present case do not result in governmental regulation of the price of new oil. A requirement to regulate the price of all crude oil, directly or indirectly, is not satisfied by an administrative scheme which affects only the average price of crude oil and not the price of each component category. Although the Supreme Court upheld a regulation of the Federal Power Commission which indirectly controlled rates charged by natural gas producers, Federal Power Commission v. Texaco, Inc., supra, that case differed critically from the present case. It came about in this way. The Natural Gas Act, 15 U.S.C. § 717, required that the Government regulate the rates charged by all producers. The administrative regulation, however, failed directly to regulate small producers of natural gas, even though they came within the scope of the Act. The *1120Supreme Court upheld the validity of the regulation because the entire output of these small, non-regulated producers was purchased only by the pipelines and large natural gas companies which would exert pressure to keep the freely floating rates in line with the “just and reasonable” rates to which the regulations compelled the larger producers to adhere. On the other hand, in the present case, the “average weighted price per barrel,” is merely a mathematical construct with no moderating effect on the price of new crude oil, which is presently set exclusively by the operation of the “law” of supply and demand. We, therefore, hold that FEA has not specified or prescribed a manner for determining the price of new crude oil and that 10 C.F.R. § 212.74(a) operates to create an invalid exemption.
We also hold that 10 C.F.R. § 212.74(a) is invalid on the separate ground that the use of the market as the sole factor in determining price fails to satisfy the statutory precept that the price of all crude be set at an equitable level.
The Emergency Petroleum Allocation Act was enacted in part in an effort to “ . . . restore and foster competition in the producing [sector] of [the petroleum] industry.” § 4(b)(1)(D). (Emphasis added.) Congress has also directed that the President,
“ . . .in exercising [his] authority, strike an equitable balance between the sometimes conflicting needs of providing adequate inducement for the production of an adequate supply of product and of holding down spiraling consumer costs.” Conference Report, 93-628, 93d Cong., 1st Sess. 26 (1973), U.S.Code Cong. & Admin.News 1973, p. 2703.
In subjecting producers to regulation because of anticompetitive conditions in the industry and because of spiraling consumer prices, it is highly unlikely that Congress assumed that “equitable” prices could be conclusively determined by reference to market price. See, Federal Power Commission v. Texaco, Inc., supra, 417 U.S. at 395dd, 94 S.Ct. 2315, 41 L.Ed.2d 141.
The Government seeks to rebut this conclusion by arguing that the prices established under the regulation at issue are “equitable” in light of the conflicting concerns of the Act with the moderation of consumer prices and the promotion of the development of new sources of supply. The Natural Gas Act’s mandate of “just and reasonable” rates requires, however, as the Supreme Court’s opinion in Texaco illustrates, precisely the same balancing of the same competing objectives. And the Court there held that a two-tier pricing system under which one tier was determined by the market price exclusively was unlawful because, while the statute may have conflicting goals, Congress did not authorize any exceptions to the requirement that all rates be “fair and reasonable.” Id. at 394dd, 94 S.Ct. 2315, 41 L.Ed.2d 141.
It is not the function of this court to determine what the equitable price is, or should be. We merely hold that the President, through the FEA, by permitting the price of new crude oil to float at free market levels, has not struck any balance and, as a result, has failed to satisfy the requirement that prices be set at an equitable level.
The judgment of the district court is reversed.
. Section 4(a) provides:
“Not later than fifteen days after the date of enactment of this Act, the President shall promulgate a regulation providing for the mandatory allocation of crude oil, residual fuel oil, and each refined petroleum product, in amounts specified in (or determined in a manner prescribed by) and at prices specified in (or determined in a manner prescribed by) such regulation. Subject to subsection (f), such regulation shall take effect not later than fifteen days after its promulgation. Except as provided in subsection (e) such regulation shall apply to all crude oil, residual fuel oil, and refined petroleum products produced in or imported into the United States.”
. Section 4(e)(2)(A) provides:
“The regulation promulgated under subsection (a) of this section shall not apply to the first sale of crude oil produced in the United States from any lease whose average daily production of crude oil for the preceding calendar year does not exceed ten barrels per well.”
. Section 4(b)(1) provides:
“The regulation under subsection (a), to the maximum extent practicable, shall provide for—
(A) protection of public health, safety, and welfare (including maintenance of residential heating, such as individual homes, apartments, and similar occupied dwelling units), and the national defense;
(B) maintenance of all public services (including facilities and services provided by municipally, cooperatively, or investor owned utilities or by any State or local government or authority, and including transportation facilities and services which serve the public at large);
(C) maintenance of agricultural operations, including farming, ranching, dairy, and fishing activities, and services directly related thereto;
(D) preservation of an economically sound and competitive petroleum industry; including the priority needs to restore and foster competition in the producing, refining, distribution, marketing, and petrochemical sectors of such industry, and to preserve the competitive viability of independent refiners, small refiners, nonbranded independent marketers, and branded independent marketers;
(E) the allocation of suitable types, grades, and quality of crude oil to refineries in the United States to permit such refineries to operate at full capacity;
(F) equitable distribution of crude oil, residual fuel oil, and refined petroleum products at equitable prices among all regions and areas of the United States and sectors of the petroleum industry, including independent refiners, small refiners, nonbranded independent marketers, branded independent marketers, and among all users;
(G) allocation of residual fuel oil and refined petroleum products in such amounts and in such manner as may be necessary for the maintenance of exploration for, and production or extraction of, fuels, and for required transportation related thereto;
(H) economic efficiency; and
(I) minimization of economic distortion, inflexibility, and unnecessary interference with market mechanisms.”
. Section 4(g)(2) provides:
“If at any time after the date of enactment of this Act the President finds that application of the regulation under subsection (a) to crude oil, residual fuel oil, or a refined petroleum product is not necessary to carry out this Act, that there is no shortage of such oil or product, and that exempting such oil or product from such regulation will not have an adverse impact on the supply of any other oil or refined petroleum products subject to this Act, he may prescribe an amendment to the regulation under subsection (a) exempting such oil or product from such regulation for a period *1116of not more than ninety days. The President shall submit any such amendment and any such findings to the Congress. An amendment under this paragraph may not exempt more than one oil or one product. Such an amendment shall take effect on a date specified in the amendment, but in no case sooner than the close of the earliest period which begins after the submission of such amendment to the Congress and which includes at least five days during which the House was in session and at least five days during which the Senate was in session; except that such amendment shall not take effect if before the expiration of such period either House of Congress approves a resolution of that House stating in substance that such House disapproves such amendment.”
. The formula set out in 10 C.F.R. § 212.-74(b) is as follows:
Where:
P max = Maximum price that may be charged for the crude petroleum (other than new crude) purchased from the property (dollars per barrel);
Pc = Ceiling price of the crude petroleum (dollars per barrel);
Cbpci = Base production control level for property (barrels);
Cpr = Total amount of crude petroleum produced from the property during the month (barrels), less the number of barrels of new crude petroleum required to be sold during the month at or below the ceiling price pursuant to the second sentence of paragraph (a) of this section; and
Pm = Current free market price of the particular quality and grade of crude petroleum (dollars per barrel).
Application of this formula may be illustrated by the following example:
Example. During September 1973, Firm X produces 8,170 barrels of a single grade of crude petroleum from a particular property. During September 1972, 6,420 barrels of crude petroleum were *1117produced from the same property. The ceiling price for the September 1973 crude petroleum is $4.10 per barrel, and its free market price (i. e., the price X can get on the market for the 1,750 barrels of new crude) is $4.95 per barrel. The maximum price that X may charge for the 6,420 barrels of other than new crude petroleum (i. e., old plus released crude) produced in September 1973 is:
P max = $4.10 + (8,170/6,420 -1) ($4.95 - $4.10)
P max = $4.10 + (.27) ($0.85)
P max = $4.10 + $0.23
P max = $4.33/barrel.”
. Although the court below did not address the issue of compliance with § 4(g)(2), we do not remand because the record unequivocally shows that an exemption, to the extent that one has been granted, is no longer valid. Appellee Sawhill promulgated the regulations at issue on January 15, 1974. Section 4(g)(2) provides that an exemption, even if validly granted, may remain in force for no more than 90 days, a period which has long since expired. To the extent that we hold that 10 C.F.R. § 212.74(a) fails to specify, or prescribe a manner for the determination of price, and that FEA has created a de facto exemption, this exemption, even if it is assumed that the other requirements of § 4(g)(2) had been satisfied, is no longer valid.
. For example, as a prerequisite to the grant of an exemption under § 4(g)(2), the President must explicitly find that “ . . . application of the [implementing regulation] is not necessary to carry out [the purposes of the Act].” An exemption from 10 C.F.R. § 212.-74(a) could only be granted, therefore, if the free operation of the market is no longer necessary to “minimize . . . interference with market mechanisms,” one of the purposes of the statute. As an alternative the district court would be forced to conclude that an exemption to 10 C.F.R. § 212.74(a) could never be granted.
Similarly, to exempt any crude oil, presently covered by the regulation, from the operation of 10 C.F.R. § 212.74(a) it would be necessary to set prices for such excluded category by some mechanism other than the exclusive operation of the free market. The President’s authority, however, to interfere in the free market derives from the Act itself. The theory underlying the decision of the trial court would lead to the conclusion that an exemption could never be granted, because, if the regulation is not necessary to carry out the purposes of the Act, then the Act cannot be cited in support of the price tampering which an exemption would necessitate. Such a result, however, would render superfluous the detailed and comprehensive section of the Act which provides an explicit procedure for the grant of exemptions. It would also prevent the President from granting exemptions in an attempt to secure “to the maximum extent practicable” the achievement of the statutory goals in meeting changing developments in the petroleum field.