delivered the opinion of the Court.

Southern Motor Carriers Rate Conference, Inc. (SMCRC), and North Carolina Motor Carriers Association, Inc. (NCMCA), petitioners, are “rate bureaus” composed of motor common carriers operating in four Southeastern States. The rate bureaus, on behalf of their members, submit joint rate proposals to the Public Service Commission in each State for approval or rejection. This collective rate-making is authorized, but not compelled, by the States in which the rate bureaus operate. The United States, contending that collective ratemaking violates the federal antitrust laws, filed this action to enjoin the rate bureaus’ alleged anticompetitive practices. We here consider whether the petitioners’ collective ratemaking activities, though not compelled by the States, are entitled to Sherman Act immunity under the “state action” doctrine of Parker v. Brown, 317 U. S. 341 (1943).

I

A

In North Carolina, Georgia, Mississippi, and Tennessee, Public Service Commissions set motor common carriers’ rates for the intrastate transportation of general commodities.1 Common carriers are required to submit proposed rates to the relevant Commission for approval.2 A proposed *51rate becomes effective if the state agency takes no action within a specified period of time. If a hearing is scheduled, however, a rate will become effective only after affirmative agency approval.3 The State Public Service Commissions thus have and exercise ultimate authority and control over all intrastate rates.

In all four States, common carriers are allowed to agree on rate proposals prior to their joint submission to the regulatory agency.4 By reducing the number of proposals, collective ratemaking permits the agency to consider more carefully each submission. In fact, some Public Service Commissions have stated that without collective ratemaking they would be unable to function effectively as rate-setting bodies.5 Nevertheless, collective ratemaking is not compelled by any of the States; every common carrier remains free to submit individual rate proposals to the Public Service Commissions.6

*52As indicated above, SMCRC and NCMCA are private associations composed of motor common carriers operating in North Carolina, Georgia, Mississippi, and Tennessee.7 Both organizations have committees that consider possible rate changes.8 If a rate committee concludes that an intrastate rate should be changed, a collective proposal for the changed rate is submitted to the State Public Service Commission. Members of the bureau, however, are not bound by the joint proposal. Any disapproving member may submit an independent rate proposal to the state regulatory Commission.9

B

On November 17, 1976, the United States instituted this action against SMCRC and NCMCA in the United States District Court for the Northern District of Georgia.10 The *53United States charged that the two rate bureaus had violated § 1 of the Sherman Act by conspiring with their members to fix rates for the intrastate transportation of general commodities. The rate bureaus responded that their conduct was exempt from the federal antitrust laws by virtue of the state action doctrine. See Parker v. Brown, 317 U. S. 341 (1943).11 They further asserted that their collective rate-making activities did not violate the Sherman Act because the rates ultimately were determined by the appropriate state agencies. The District Court found the rate bureaus’ arguments meritless, and entered a summary judgment in favor of the Government. 467 F. Supp. 471 (1979). The defendants were enjoined from engaging in collective rate-making activities with their members.

The Court of Appeals for the Fifth Circuit (Unit B, now the Eleventh Circuit), sitting en banc, affirmed the judgment of the District Court. 702 F. 2d 532 (1983).12 Relying primarily on Goldfarb v. Virginia State Bar, 421 U. S. 773 (1975), the court held that the rate bureaus’ challenged conduct, because it was not compelled by the State, was not entitled to Parker immunity. The two-pronged test set forth in California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc., 445 U. S. 97 (1980), was irrelevant, the court reasoned, for in that case a public official was the *54named defendant.13 702 F. 2d, at 539. The Court of Appeals further held that even if Midcal were applicable to a private party’s claim of state action immunity, the rate bureaus were not shielded from liability under the Sherman Act. The court concluded that only if the anticompetitive acts of a private party are compelled can a State’s policy be held “clearly articulated and affirmatively expressed” within the meaning of Midcal. 702 F. 2d, at 539.

After finding the rate bureaus not entitled to Parker immunity, the Court of Appeals held that their collective rate-making activities violated the Sherman Act. 672 F. 2d 469, 481 (1982).14 It rejected the rate bureaus’ contention that because the regulatory agencies had ultimate authority and control over the rates charged, the federal antitrust laws were not violated. The Court of Appeals found that “joint ratesetting . . . reduce[d] the amount of independent rate filing that otherwise would characterize the market process,” and thus raised the prices charged for intrastate transportation of general commodities. Id., at 478. This “naked price restraint,” the court reasoned, is per se illegal. Ibid.

Four judges strongly dissented. They argued that Midcal was applicable to a private party’s claim of state action immunity. The success of an antitrust action should depend upon the activity challenged rather than the identity of the defendant. 702 F. 2d, at 543-544. After asserting that Midcal provided the relevant test, the dissenters concluded that the lack of compulsion was not dispositive. Even in the absence of compulsion, a “state can articulate a clear and express policy.” Id., at 546. The dissent further concluded that a per se compulsion requirement denies States needed flexibility in the formation of regulatory programs, and thus is *55inconsistent with the principles of federalism that Congress intended to embody in the Sherman Act.15

We granted certiorari,16 467 U. S. 1240 (1984), to decide whether petitioners’ collective ratemaking activities, though not compelled by the States in which they operate, are entitled to Parker immunity.17

II

In Parker v. Brown, 317 U. S., at 341, this Court held that the Sherman Act was not intended to prohibit States from imposing restraints on competition.18 There, a raisin pro*56ducer filed an action against the California Director of Agriculture to enjoin the enforcement of the State’s Agricultural Prorate Act. Under that statute, a cartel of private raisin producers was created in order to stabilize prices and prevent “economic waste.” Id., at 346. The Court recognized that the State’s program was anticompetitive, and it assumed that Congress, “in the exercise of its commerce power, [could] prohibit a state from maintaining [such] a stabilization program . . . .” Id., at 350. Nevertheless, the Court refused to find in the Sherman Act “an unexpressed purpose to nullify a state’s control over its officers and agents . . . .” Id., at 351.

Although Parker involved an action against a state official, the Court’s reasoning extends to suits against private parties. The Parker decision was premised on the assumption that Congress, in enacting the Sherman Act, did not intend to compromise the States’ ability to regulate their domestic commerce.19 If Parker immunity were limited to the actions of public officials, this assumed congressional purpose would be frustrated, for a State would be unable to implement programs that restrain competition among private parties. A plaintiff could frustrate any such program merely by filing suit against the regulated private parties, rather than the *57state officials who implement the plan. We decline to reduce Parker's holding to a formalism that would stand for little more than the proposition that Porter Brown sued the wrong parties. Cantor v. Detroit Edison Co., 428 U. S. 579, 616-617, n. 4 (1976) (Stewart, J., dissenting).

The circumstances in which Parker immunity is available to private parties, and to state agencies or officials regulating the conduct of private parties, are defined most specifically by our decision in California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc., 445 U. S., at 97. See Hallie v. Eau Claire, ante, at 46, n. 10. In Midcal, we affirmed a state-court injunction prohibiting officials from enforcing a statute requiring wine producers to establish resale price schedules. We set forth a two-pronged test for determining whether state regulation of private parties is shielded from the federal antitrust laws. First, the challenged restraint must be “ ‘one clearly articulated and affirmatively expressed as state policy.’” 445 U. S., at 105, quoting Lafayette v. Louisiana Power & Light Co., 435 U. S. 389, 410 (1978) (opinion of Brennan, J.). Second, the State must supervise actively any private anticompetitive conduct. 445 U. S., at 105.20 This supervision requirement prevents the State from frustrating the national policy in favor of competition by casting a “gauzy cloak of state involvement” over what is essentially private anticompetitive conduct. Id., at 106.21

*58I — H 1 — 4

The Midcal test does not expressly provide that the actions of a private party must be compelled by a State in order to be protected from the federal antitrust laws. The Court of Appeals, however, held that compulsion is a threshold requirement to a finding of Parker immunity. It reached this conclusion by finding that: (i) Midcal is inapplicable to suits brought against private parties; (ii) even if Midcal is applicable, private conduct that is not compelled cannot be taken pursuant to a “clearly articulated state policy,” within the meaning of Midcal’s first prong; and (iii) because Gold-farb was cited with approval in Midcal, the Midcal Court endorsed the continued validity of a “compulsion requirement.” We consider these points in order.

A

The Court of Appeals held that Midcal, that involved a suit against a state agency, is inapplicable where a private party is the named defendant. Midcal, however, should not be given such a narrow reading. In that case we were concerned, as we are here, with state regulation restraining competition among private parties. Therefore, the two-pronged test set forth in Midcal should be used to determine whether the private rate bureaus’ collective ratemaking activities are protected from the federal antitrust laws. The success of an antitrust action should depend upon the nature of the activity challenged, rather than on the identity of the *59defendant. See Cantor v. Detroit Edison Co., supra, at 604 (Burger, C. J., concurring in part and concurring in judgment); Lafayette v. Louisiana Power & Light Co., supra, at 420 (Burger, C. J., concurring in part and concurring in judgment).

B

The Court of Appeals held that even if Midcal were applicable here, the rate bureaus would not be immune from federal antitrust liability. According to that court, the actions of a private party cannot be attributed to a clearly articulated state policy, within the meaning of the Midcal test’s first prong, “when it is left to the private party to carry out that policy or not as he sees fit.” 702 F. 2d, at 539. In the four States in which petitioners operate, all common carriers are free to submit proposals individually. The court therefore reasoned that the States’ policies are neutral with respect to collective ratemaking, and that these policies will not be frustrated if the federal antitrust laws are construed to require individual submissions.

In reaching its conclusion, the Court of Appeals assumed that if anticompetitive activity is not compelled, the State can have no interest in whether private parties engage in that conduct. This type of analysis ignores the manner in which the States in this case clearly have intended their permissive policies to work. Most common carriers probably will engage in collective ratemaking, as that will allow them to share the cost of preparing rate proposals. If the joint rates are viewed as too high, however, carriers individually may submit lower proposed rates to the Commission in order to obtain a larger share of the market. Thus, through the self-interested actions of private common carriers, the States may achieve the desired balance between the efficiency of collective ratemaking and the competition fostered by individual submissions. Construing the Sherman Act to prohibit collective rate proposals eliminates the free choice necessary to ensure that these policies function in the manner intended *60by the States. The federal antitrust laws do not forbid the States to adopt policies that permit, but do not compel, anti-competitive conduct by regulated private parties. As long as the State clearly articulates its intent to adopt a permissive policy, the first prong of the Midcal test is satisfied.22

C

In Goldfarb v. Virginia State Bar, 421 U. S. 773 (1975), this Court said that “[t]he threshold inquiry in determining if an anticompetitive activity is state action of the type the Sherman Act was not meant to proscribe is whether the activity is required by the State acting as sovereign.” Id., at 790. Midcal cited Goldfarb with approval. 445 U. S., at 104. On the basis of this citation, the Court of Appeals reasoned that Midcal did not eliminate the “compulsion requirement” of Goldfarb.

Goldfarb, however, is not properly read as making compulsion a sine qua non to state action immunity. In that case, the Virginia State Bar, a state agency, compelled Fairfax County lawyers to adhere to a minimum-fee schedule. 421 U. S., at 776-778. The Goldfarb Court therefore was not concerned with the necessity of compulsion — its presence in the case was not an issue. The focal point of the Goldfarb opinion was the source of the anticompetitive policy, rather than whether the challenged conduct was compelled. The Court held that a State Bar, acting alone, could not immunize its anticompetitive conduct. Instead, the Court held that private parties were entitled to Parker immunity only if the State “acting as sovereign” intended to displace competition. 421 U. S., at 790; see Lafayette v. Louisiana Power *61& Light Co., 435 U. S., at 410 (opinion of Brennan, J.) (“Goldfarb . . . made it clear that, for purposes of the Parker doctrine, not every act of a state agency is that of the State as sovereign”).

Although Goldfarb did employ language of compulsion, it is beyond dispute that the Court would have reached the same result had it applied the two-pronged test later set forth in Midcal. As stated above, Virginia “as sovereign” did not have a “clearly articulated policy” designed to displace price competition among lawyers. In fact, the Supreme Court of Virginia had explicitly directed lawyers not “to be controlled” by minimum-fee schedules. Goldfarb, supra, at 789, n. 19. Although we recognize that the language in Goldfarb is not without ambiguity, we do not read that opinion as making compulsion a prerequisite to a finding of state action immunity.

D

The Parker doctrine represents an attempt to resolve conflicts that may arise between principles of federalism and the goal of the antitrust laws, unfettered competition in the marketplace. A compulsion requirement is inconsistent with both values. It reduces the range of regulatory alternatives available to the State. At the same time, insofar as it encourages States to require, rather than merely permit, anticompetitive conduct, a compulsion requirement may result in greater restraints on trade. We do not believe that Congress intended to resolve conflicts between two competing interests by impairing both more than necessary.

In summary, we hold Midcal’s two-pronged test applicable to private parties’ claims of state action immunity. Moreover, a state policy that expressly permits, but does not compel, anticompetitive conduct may be “clearly articulated” within the meaning of Midcal,23 Our holding today does not *62suggest, however, that compulsion is irrelevant. To the contrary, compulsion often is the best evidence that the State has a clearly articulated and affirmatively expressed policy to displace competition. See Hallie v. Eau Claire, ante, at 45-46; 1 P. Areeda & D. Turner, Antitrust Law ¶212.5, p. 62 (Supp. 1982) (compulsion is “powerful evidence” of existence of state policy). Nevertheless, when other evidence conclusively shows that a State intends to adopt a permissive policy, the absence of compulsion should not prove fatal to a claim of Parker immunity.

IV

A

Our holding that there is no inflexible compulsion requirement” does not suggest necessarily that petitioners’ collective ratemaking activities are shielded from the federal antitrust laws. A private party may claim state action immunity only if both prongs of the Midcal test are satisfied. Here the Court of Appeals found, and the Government concedes, that the State Public Service Commissions actively supervise the collective ratemaking activities of the rate bureaus. Therefore, the only issue left to resolve is whether the petitioners’ challenged conduct was taken pursuant to a clearly articulated state policy.

The Public Service Commissions in North Carolina, Georgia, Mississippi, and Tennessee permit collective ratemaking. See n. 4, supra. Acting alone, however, these agencies *63could not immunize private anticompetitive conduct. In Goldfarb, the State Bar — a special type of “state agency”— prohibited lawyers from charging fees lower than those set forth in schedules published by the local bar. Nevertheless, this Court held that the local lawyers were not immune from antitrust liability because their anticompetitive conduct was not required by the State as sovereign. 421 U. S., at 790. Parker immunity is available only when the challenged activity is undertaken pursuant to a clearly articulated policy of the State itself, such as a policy approved by a state legislature, see New Motor Vehicle Bd. of Cal. v. Orrin W. Fox Co., 439 U. S. 96 (1978), or a State Supreme Court, Bates v. State Bar of Arizona, 433 U. S. 350 (1977).

In this case, therefore, the petitioners are entitled to Parker immunity only if collective ratemaking is clearly sanctioned by the legislatures of the four States in which the rate bureaus operate. North Carolina, Georgia, and Tennessee have statutes that explicitly permit collective ratemaking by common carriers.24 The rate bureaus’ challenged actions, at least in these States, are taken pursuant to an express and clearly articulated state policy. Mississippi’s legislature, however, has not specifically addressed collective ratemak-ing. We therefore must consider whether, in the absence of a statute expressly permitting the challenged conduct, the first prong of the Midcal test can be satisfied.

B

The Mississippi Motor Carrier Regulatory Law of 1938, Miss. Code Ann. § 77-7-1 et seq. (1972 and Supp. 1984), gives the State Public Service Commission authority to regulate common carriers. The statute provides that the Commission is to prescribe “just and reasonable” rates for the intrastate transportation of general commodities. §77-7-221. The legislature thus made clear its intent that intrastate rates *64would be determined by a regulatory agency, rather than by the market. The details of the inherently anticompetitive rate-setting process, however, are left to the agency’s discretion. The State Commission has exercised its discretion by actively encouraging collective ratemaking among common carriers. See Response of the State of Mississippi and the Mississippi Public Service Comm’n as Amici Curiae in District Court, No. 76-1909A (ND Ga. 1977), p. 11. We do not believe that the actions petitioners took pursuant to this regulatory program should be deprived of Parker immunity.

A private party acting pursuant to an anticompetitive regulatory program need not “point to a specific, detailed legislative authorization” for its challenged conduct. Lafayette v. Louisiana Power & Light Co., 435 U. S., at 415 (opinion of Brennan, J.). As long as the State as sovereign clearly intends to displace competition in a particular field with a regulatory structure, the first prong of the Midcal test is satisfied. In Goldfarb, the Court held that Parker immunity was unavailable only because the State as sovereign did not intend to do away with competition among lawyers. 421 U. S., at 790. Similarly, in Cantor the anti-competitive acts of a private utility were held unprotected because the Michigan Legislature had indicated no intention to displace competition in the relevant market. 428 U. S., at 584-585.

If more detail than a clear intent to displace competition were required of the legislature, States would find it difficult to implement through regulatory agencies their anti-competitive policies. Agencies are created because they are able to deal with problems unforeseeable to, or outside the competence of, the legislature. Requiring express authorization for every action that an agency might find necessary to effectuate state policy would diminish, if not destroy, its usefulness. Cf. Hallie v. Eau Claire, ante, at 44 (requiring explicit legislative authorization of anti-competitive activity would impose “detrimental side effects upon municipalities’ local autonomy”). Therefore, we hold *65that if the State’s intent to establish an anticompetitive regulatory program is clear, as it is in Mississippi,25 the State’s failure to describe the implementation of its policy in detail will not subject the program to the restraints of the federal antitrust laws.

C

In summary, we hold that the petitioners’ collective rate-making activity is immune from Sherman Act liability. This anticompetitive conduct is taken pursuant to a “clearly articulated state policy.” The legislatures of North Carolina, Georgia, and Tennessee expressly permit motor common carriers to submit collective rate proposals to Public Service Commissions, which have the authority to accept, reject, or modify any recommendation. Mississippi, the fourth State in which the petitioners operate, has not expressly approved of collective ratemaking, but it has articulated clearly its intent to displace price competition among common carriers with a regulatory structure. Anticompetitive conduct taken pursuant to such a regulatory program satisfies the first *66prong of the Midcal test. The second prong of the Midcal test likewise is met, for the Government has conceded that the relevant States, through their agencies, actively supervise the conduct of private parties.

Y

We conclude that the petitioners’ collective ratemaking activities, although not compelled by the States, are immune from antitrust liability under the doctrine of Parker v. Brown. Accordingly, the judgment of the Court of Appeals is reversed.

It is so ordered.

with whom Justice White joins, dissenting.

The term “price fixing” generally refers to a process by which competitors agree upon the prices that will prevail in the market for the goods or services they offer. Such behavior is not essential to every public program for regulating industry. In this case, for example, four Southern States have established programs for evaluating the reasonableness of rates that motor carriers propose to charge for intrastate transport, but the States do not require price fixing by motor carriers. They merely tolerate it.

Reasoning deductively from a dictum in California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc., 445 U. S. 97, 105 (1980), the Court holds that Congress did not intend to prohibit price fixing by motor carrier rate bureaus — at least when such conduct is prompted, but not required, by a State Public Service Commission. The result is inconsistent with the language1 and policies of the Sherman Act, and this Court’s precedent. The Sherman Act only would interfere with the regulatory process if the States compelled price *67fixing that is unlawful under federal law. In that situation, the regulated carriers would face conflicting obligations under state and federal law, and the success of the States’ regulatory programs would be threatened. Except under those circumstances, immunity from the antitrust laws under the state-action doctrine is not available for private persons.2

H-{

Whatever may be its peculiar problems and characteristics, the Sherman Act, so far as price-fixing agreements are concerned, establishes one uniform rule applicable to all industries alike”:3 agreements and combinations tampering with competitive price structures are unlawful. State legislatures, whose powers are limited by the Supremacy Clause,4 may not expressly modify the obligations of any person under this federal law. Only Congress, expressly or by implication, may authorize price fixing, and has done so in particular industries or compelling circumstances. Implied antitrust immunities, however, are disfavored,5 and any exemptions *68from the antitrust laws are to be strictly construed.6 These “canon[s] of construction . . . reflec[t] the felt indispensable role of antitrust policy in the maintenance of a free economy.” United States v. Philadelphia National Bank, 374 U. S. 321, 348 (1963).

Applying these principles, this Court has consistently embraced the view that “[r]egulated industries are not per se exempt from the Sherman Act.” Georgia v. Pennsylvania R. Co., 324 U. S. 439, 456 (1945). For many years prior to the enactment of the Sherman Act, state agencies regulated the business of insurance, but we rejected the view that these programs of public scrutiny supported “our reading into the Act an exemption” allowing insurance businesses to fix premium rates and agents’ commissions. United States v. South-Eastern Underwriters Assn., 322 U. S. 533, 559 (1944). In South-Eastern Underwriters, the Court tersely observed that “if exceptions are to be written into the Act, they must come from Congress, not this Court.” Id., at 561. Thereafter, in the McCarran-Ferguson Act of 1945, 59 Stat. 33, Congress decided, as a matter of policy, that the Sherman Act’s prohibition of price fixing “shall [only] be applicable to the business of insurance to the extent that such business is not regulated by State Law.” 15 U. S. C. § 1012(b).

Consistent with its treatment of the insurance business in South-Eastern Underwriters, this Court has repeatedly held that collusive price fixing by railroads is unlawful even though the end result is a reasonable charge approved by a public rate commission.7 Georgia v. Pennsylvania R. Co., *69324 U. S., at 455-463.; United States v. Trans-Missouri Freight Assn., 166 U. S. 290, 337-340 (1897). In the Pennsylvania Railroad case, the Court explained why this is so:

“The fact that the rates which have been fixed may or may not be held unlawful by the [Interstate Commerce] Commission is immaterial to the issue before us. . . . [E]ven a combination to fix reasonable and nondiscriminatory rates may be illegal. [Keogh v. Chicago & Northwestern R. Co., 260 U. S. 156, 161 (1922)]. The reason is that the Interstate Commerce Act does not provide remedies for the correction of all the abuses of rate-making which might constitute violations of the anti-trust laws. Thus a ‘zone of reasonableness exists between maxima and minima within which a carrier is ordinarily free to adjust its charges for itself.’ United States v. Chicago, M., St. P. & P. R. Co., 294 U. S. 499, 506 [1935]. Within that zone the Commission lacks power to grant relief even though the rates are raised to the maxima by a conspiracy among carriers who employ *70unlawful tactics. . . . Damage must be presumed to flow from a conspiracy to manipulate rates within that zone.” 324 U. S., at 460-461.

Collusive price fixing by regulated carriers causes upward pressure on rates within the zone of reasonableness, and such combinations and conspiracies are generally actionable under the Sherman Act on the theory of the Pennsylvania Railroad case.

Congress reacted to the Pennsylvania Railroad decision much as it reacted to the South-Eastern Underwriters decision. It decided, as a matter of policy, that some price fixing should be permitted in the transportation industry, and enacted the Reed-Bulwinkle Act of 1948 to effectuate that policy choice.8 In the Motor Carrier Act of 1980,9 however, Congress sharply curtailed the availability of this antitrust exemption. Collective ratemaking is still permitted in limited circumstances, but rate bureaus must comply with strict procedural requirements. See n. 19, infra.

The defendants have stipulated that their price-fixing arrangements are identical to those followed by the Carrier Rate Committees in the Pennsylvania Railroad case which were declared unlawful under the Sherman Act. See App. 40-41. They also acknowledge that neither the Reed-Bulwinkle Act nor any other federal statute expressly exempts their price fixing from the antitrust laws. Nevertheless, they contend that Congress would not have intended to prohibit collective ratemaking by intrastate motor carriers when it is permitted, but not required, by state law.

*71HH I — <

The basis for the defendants’ claim of implied immunity from the antitrust laws is the state-action doctrine of Parker v. Brown, 317 U. S. 341 (1943). This Court, however, has repeatedly recognized that private entities may not claim the state-action immunity unless their unlawful conduct is compelled by the State.

In the Parker case, this Court held that the Sherman Act does not reach “state action or official action directed by a state.” Id., at 351. The case involved price fixing that was mandated by a California statute in the furtherance of a price-support program for raisin farmers. The Court held that the price fixing was not prohibited by the Sherman Act:

“[T]he prorate program here was never intended to operate by force of individual agreement or combination. It derived its authority and its efficacy from the legislative command of the state and was not intended to operate or become effective without that command. We find nothing in the language of the Sherman Act or in its history which suggests that its purpose was to restrain a state or its officers or agents from activities directed by its legislature.” Id., at 350-351.

Under Parker, private anticompetitive conduct must be “directed” by the State to be eligible for the state-action immunity.

In a later case involving price fixing by attorneys through minimum-fee schedules, the Court unanimously stated: “The threshold inquiry in determining if an anticompetitive activity is state action of the type the Sherman Act was not meant to proscribe is whether the activity is required by the State acting as sovereign. Parker v. Brown, 317 U. S., at 350-352; Continental Co. v. Union Carbide, 370 U. S. 690, 706-707 (1962).” Goldfarb v. Virginia State Bar, 421 U. S. 773, 790 (1975). In Goldfarb, no state statute or Supreme Court rule required the defendant County Bar Association to *72adopt the minimum-fee schedule, and this Court concluded that this “is not state action for Sherman Act purposes. It is not enough that, as the County Bar puts it, anticompetitive conduct is 'prompted’ by state action; rather, anticompetitive activities must be compelled by direction of the State acting as a sovereign.” Id., at 791.

In Cantor v. Detroit Edison Co., 428 U. S. 579 (1976), the Court was also unanimous in its understanding that sovereign compulsion was a prerequisite for state-action immunity.10 The opinion for the Court observed that it has long been settled “that state authorization, approval, encouragement, or participation in restrictive private conduct confers no antitrust immunity.” Id., at 592-593 (footnotes omit-. ted).11 The dissenting Justices agreed: “private conduct, if it is to come within the state-action exemption, must be not merely ‘prompted’ but ‘compelled’ by state action.” Id., at 637 (Stewart, J., dissenting, joined by Powell and Rehn-QUIST, JJ.).

In Cantor, the Court only divided on the question whether the compulsion requirement alone was sufficient to confer antitrust immunity. The dissent argued that Congress would not have intended to penalize Detroit Edison for engaging in a light-bulb-distribution program that had been approved by the Michigan Public Service Commission and that could not be discontinued without approval of the Commission. Id., at 614-615. The Court, on the other hand, acknowledged that continuation of the light-bulb program was ostensibly required by the State, but went on to consider *73whether an antitrust exemption for this conduct was fundamental to the State’s regulatory program. Since Michigan’s statutes only expressed an interest in regulating the electricity market, and not the light-bulb market, the Court concluded that “[rjegardless of the outcome of this case, Michigan’s interest in regulating its utilities’ distribution of electricity will be almost entirely unimpaired.” Id., at 598. Because the State had not articulated any intention to regulate the light-bulb market, and the idea for the distribution program had come from the private utility, the State’s requirement that the program continue was not sufficient to establish state-action immunity from the antitrust laws.

The Court’s unanimous decision in California Retail Liquor Dealers Assn. v. Midcal Aluminum, Inc., 445 U. S. 97 (1980), signaled no departure from settled principles in this area. In discussing the principles of law applicable to state-action immunity, the Court quoted extensively from the language in Parker and Goldfarb12 that recognized the compulsion requirement. In any case, it was quite clear in Midcal that the California statutes required the unlawful resale-price-maintenance activities. Thus, this Court had no occasion in that case to explore the contours of the compulsion requirement. The references, in the Midcal opinion, to “clearly articulated and affirmatively expressed” policies and “actively supervised” activities merely restated the standards to be applied in evaluating whether conduct ostensibly compelled by the State is entitled to the state-action immunity. These requirements limited the scope of the *74state-action immunity for private entities; they did not expand the immunity to protect conduct that is merely prompted by the State.13

Ill

Today the Court abandons the settled view that a private party is not entitled to state-action immunity unless the State compelled him to act in violation of federal law. Hereafter, a State may exempt price fixing from the federal antitrust laws if it clearly articulates its intention to supplant competition with regulation in the relevant market, and if it actively supervises the unlawful conduct by evaluating the reasonableness of the prices charged. The Court justifies this change in the law by finding it more consistent with “principles of federalism and the goal of the antitrust laws, unfettered competition in the marketplace.” Ante, at 61. I believe these conclusions are unsound.

Deference to State Regulatory Programs

The Court’s reliance today on vague “principles of federalism” obscures our traditional disfavor for implied exemptions to the Sherman Act. We have only authorized exemptions from the Sherman Act for businesses regulated by federal law when “that exemption was necessary in order to make the regulatory Act work ‘and even then only to the minimum extent necessary.’”14 No lesser showing of repugnancy *75should be sufficient to justify an implied exemption based on a state regulatory program.

Any other view separates the state-action exemption from the reason for its existence. The program involved in the Parker case was designed to enhance the market price of raisins by regulating both output and price.15 In other words, the state policy was one that replaced price competition with economic regulation. Price support programs like the one involved in Parker cannot possibly succeed if every individual producer is free to participate or not participate in the program at his option. In Parker, the challenged price fixing was the heart of California’s support program for agriculture; without immunity from the Sherman Act, the State would have had to abandon the project.

In this case, the common denominator in the States’ regulatory programs for motor carriers is their reservation of the power to evaluate the reasonableness of proposed rates and *76terms of carriage.16 In these programs, “no State requires that all rates among competing carriers for identical service be uniform, [and] no State requires, either by statute or regulation, or other express legislative or administrative mandate, that rates proposed by carriers be formulated by rate conferences.” 467 F. Supp. 471, 477 (ND Ga. 1979). When, as here, state regulatory policies are permissive rather than mandatory, there is no necessary conflict between the antitrust laws and the regulatory systems; the regulated entity may comply with the edicts of each sovereign. Indeed, it is almost meaningless to contemplate a “regulatory” policy that gives every regulated entity carte blanche to excuse itself from the consequences of the regulation. Even a policy against speeding could not be enforced if every motorist could drive as fast as he chose. When a State declares that a regulated entity need not follow a regulatory procedure, it as much as admits that this element is inconsequential to the ultimate success of the regulatory program.17

*77As I have noted, the Reed-Bulwinkle Act18 authorizes collective ratemaking by interstate carriers under some circumstances. The Court doubts whether “Congress intended to prevent the States from adopting virtually identical policies at the intrastate level.” Ante, at 60, n. 22. The Reed-Bulwinkle exemption, however, has been abolished for single-line rate requests, and to the extent that it still applies to general rate requests, the rate bureaus must follow stringent procedural safeguards which channel their conduct into useful informational tasks and thereby diminish the threat of anticompetitive misconduct.19 Even if there were sound policy reasons20 for extending the Reed-Bulwinkle exemp*78tion, as amended, to a state regulatory program that did not contain comparable procedural safeguards, “[t]hese considerations are . . . not for us. . . . Congress is the body to amend [the statute] and not this court, by a process of judicial legislation wholly unjustifiable.” United States v. Trans-Missouri Freight Assn., 166 U. S., at 340.

The Policy of Competition

The Court embraces the defendants’ specious argument that “insofar as it encourages States to require, rather than merely permit, anticompetitive conduct, a compulsion requirement may result in greater restraints on trade.” Ante, at 61. The Court finds this “result” inconsistent with the policies of the Sherman Act. This argument is seriously flawed.

On a practical level, the Court’s- argument assumes that a decision for the Government today would cause the States to rush into enactment legislation compelling price fixing in the motor carrier industry. Moreover, the Court’s argument assumes that a Congress that only recently has acted to increase competition in the interstate motor carrier field would remain silent in the face of anticompetitive legislation at the intrastate level. These assumptions are wholly speculative.

On a more theoretical level, the Court ignores the anti-competitive effect of the collective ratemaking practices challenged in this litigation.21 The Court of Appeals correctly observed that “[c]ollective [rate] formulation clearly tampers with the price structure for intrastate commodities; the rate *79bureau arrangement substitutes concerted pricing decisions among competing carriers for the influence of impersonal market forces on proposed rates.” 672 F. 2d 469, 478 (CA5, Unit B, now CA11, 1982). The increased rates for transportation caused by this behavior are especially grave in a basic industry, like transportation, where the ripple effects of the increased rates are magnified as raw materials, semifinished and finished goods are transported at various stages of production and distribution.

Active supervision of the rate bureau process — like that provided in the Motor Carrier Act of 1980 — might minimize the anticompetitive effects of collective ratemaking.22 To the extent that the State Regulatory Commissions are structured like the ICC in the Pennsylvania Railroad case, however, they only have the power to reject the rates proposed by the carriers if those rates fall outside the “zone of reasonableness.” Unless the Commissions “actively supervise” the price-fixing process itself, they cannot eliminate the upward pressure on rates caused by collusive ratemaking. Unfortunately, the nature of the “active supervision” of those carriers who take part in collective ratemaking is not fully disclosed by the record.23

IV

Whether it is wise or unwise policy for the Federal Government to seek to enforce the Sherman Act in this case is not a question that this Court is authorized to consider. The District Court and the Court of Appeals correctly applied established precedent in holding that the Government is en*80titled to an injunction against the defendants’ price fixing. Such price fixing is unlawful unless it is expressly authorized by statute, or required by a State’s regulatory program. Today the Court authorizes collective ratemaking by intrastate motor carriers even though the State has only permitted it in a program regulating the reasonableness of prices in the industry. Immunity of this type was rejected by the Court in the South-Eastern Underwriters and Pennsylvania Railroad cases, but today, under the shroud of the state-action doctrine,24 it is resurrected.

Accordingly, I respectfully dissent.