dissenting.
Today the Court orders dismissal of a suit challenging the hiring practices of the Los Angeles County Pire Department. *637The dismissal is predicated on the view that the case has become moot. This disposition of the case is opposed by petitioners, and is not urged by respondents either in their briefs or oral argument. But apart from this, I believe the Court's decision misapplies settled principles of mootness, and think the case is properly before us. We should reach, rather than seek a questionable means of avoiding, the important question — heretofore unresolved by this Court— whether cases brought under 42 U. S. C. § 1981, like those brought directly under the Fourteenth Amendment, require proof of racially discriminatory intent or purpose.
This suit was brought to eliminate the effects of alleged racial discrimination in the Los Angeles County Fire Department. The plaintiffs, respondents here, were persons who applied unsuccessfully for fireman jobs in 1971; the class they represented was certified to include present and future, but not past, black and Mexican-American job applicants to the Fire Department. The county was accused of a variety of employment practices said to discriminate against minorities, including the use of “written tests as a promotion and hiring selection device” even though the tests had “disproportionate detrimental impact” on blacks and Mexican-Americans. App. 4. The named plaintiffs had taken the most recent of these tests, which was administered in January 1972. The use of the tests, together with other actions of the county that plaintiffs described as discriminatory,1 was alleged to be re*638sponsible for substantially fewer blacks and Mexican-Americans being employed by the Fire Department than were present in the’population it served.
The District Court found that the county had engaged in employment discrimination and imposed a comprehensive racially based hiring order.2 In granting this relief, the court apparently acted under the assumption that the plaintiff class had standing to attack acts of discrimination that occurred before any of the class members applied for employment in 1971. The Court of Appeals for the Ninth Circuit reversed this determination. As no past applicants were included in the plaintiff class, the court held that respondents could not challenge the legality of employment practices which had no effect on post-1971 hiring. Respondents therefore were held to lack standing to challenge the civil service test administered in 1969, as the list of eligible applicants drawn up on the basis of that test had been exhausted before any of the class members had sought employment. 566 F. 2d 1334, 1337-1338 (1977). A majority of the panel nonetheless affirmed the District Court’s hiring order. Id., at 1343-1344.
Respondents have not sought review of the determination of standing by the court below. Accordingly, the county’s *639use of the 1972 test is the only employment practice now before us. This narrows the controversy considerably from its original dimensions, but it does not follow that a case or controversy between the county and respondents no longer exists. This is evident from a review of the facts.
The 1972 test was the same as the one administered in 1969, except that some attempt had been made to screen out questions thought to reflect cultural bias. After grading the test, the county announced it would interview only the 544 applicants with the highest scores, rather than the 2,338 applicants who achieved a passing score. On January 8, 1973, five days after interviews began, the county changed its plans and decided to interview all applicants who had passed.3 Respondents filed this suit on January 11, 1973. In their second amended complaint, filed on April 16, 1973, respondents alleged that the county decided not to use the 1972 test as a screening device only because suit was about to be filed, App. 5, and that the county would reinstitute such use unless an injunction were issued, id., at 7. The District Court found that the 1972 test was among the discriminatory employment practices in which the county engaged,4 and that the county had dropped its plan to tie interviews to test performance because of the then pending suit. Id., at 39.
The court below agreed that the county’s attempt to use the 1972 test as a selection device "had an adverse impact on the *640racial class of plaintiffs.” 566 F. 2d, at 1338 n. 6. In its view, respondents therefore had standing to attack this conduct. After determining what it considered to be the proper standard for liability under § 1981, the court held that “the district court properly found defendants’ use of the 1972 written examination as a selection device to be a violation of § 1981.” 566 F. 2d, at 1341. Turning to the scope of the relief ordered, a majority of the panel expressed its approval of the District Court’s remedial order. Looking at the judicial “power under § 1981,” id., at 1342, the majority ruled that “the district court properly exercised its discretion in ordering affirmative action to be undertaken to erase the effects of past discrimination.” Id., at 1343.5
In addition to requiring an affirmative employment program to achieve specified racial percentages in hiring, the District Court ordered that petitioners “are permanently enjoined and restrained from engaging in any employment practice which discriminates on the basis of race or national origin against the class represented by Plaintiffs in this Action . . . .” *641App. 45. If the District Court was correct, as the court below held, in ruling that the threatened use of the 1972 test was an employment practice that discriminated on the basis of race, then an order to prevent the county from carrying out its threat would have been appropriate. The fact that wrongful conduct has not yet transpired does not leave a court powerless to prevent the threatened wrong, if the likelihood of harm is sufficiently substantial. Doran v. Salem Inn, Inc., 422 U. S. 922, 930-932 (1975); Steffel v. Thompson, 415 U. S. 452, 458-460 (1974); Doe v. Bolton, 410 U. S. 179, 188 (1973). Cf. Worth v. Seldin, 422 U. S. 490, 499 (1975); Linda R. S. v. Richard D., 410 U. S. 614, 617 (1973).6
The Court nonetheless holds that this case has become moot, because “there can be no reasonable expectation that petitioners will use an. unvalidated civil service examination for the purposes contemplated in 1972,” ante, at 631-632. This assumption is contrary to findings of fact by the courts below, is opposed by the parties who are subject to the order to be dismissed, and manifestly is at odds with the record in this case.
Neither of the courts below regarded the county’s planned use of the 1972 test as solely a response to what the Court characterizes as a “temporary emergency shortage of firefighters.” Ante, at 632. The District Court, in assessing whether petitioners’ announced intention to use the 1972 test as a *642selection device violated § 1981, found that this lawsuit was responsible for' the county’s change in hiring procedures from interviewing only high scorers to considering everyone who passed the test. App. 39. The Court of Appeals agreed, and held: “[Petitioners’] decision, prompted solely by the filing of this lawsuit, to abandon the written exam as a selection device does not moot the claim.” 566 F. 2d, at 1341.
Nor have petitioners altered their position on the legality of their use of testing since the decision below. Rather, petitioners strongly assert that the controversy is still a live one. The only suggestion of mootness that has been raised in this case comes from the N. A. A. C. P. Legal Defense and Educational Fund, an organization which is an amicus curiae here but has not participated previously in this litigation. Petitioners have attacked this assertion and the factual assumptions on which it rests:
“The NAACP in reliance on statements of fact that appear absolutely nowhere in the record, gratuitously advance the novel theory that the petitioners have not been hiring under compulsion of the quota order since it was entered in 1973. This contention is not only irrelevant to the issue of the validity of the quota order, but is simply not correct. The amicus’ factual representation itself describes a quota when it states that all applicants are reduced down to three groups of whites, blacks and Mexican-Americans in exact proportion to the 1-1-3 hiring order.” Reply Brief for Petitioners 20 n. 7.
Petitioners continue to use civil service examinations as a threshold barrier for employment consideration, and the record is silent on their validation. To comply with the District Court’s order, petitioners have added additional steps to the hiring process to take account of the race of the applicants. The test scores of applicants are ranked separately within each racial group, and the highest scorers are selected for *643interviews in the exact racial proportions specified by the court order. Among those applicants who receive an interview, preference is given to minority group members. But these steps clearly are the product of the injunction at issue here and do not represent, as the Court’s opinion states, a voluntary affirmative-action program.
. The fact that the county, upon pain of contempt, has substantially altered its use of examinations by the addition of other steps that take account of applicants’ race hardly can support a finding that “there is no reasonable expectation” the county will abandon its additional procedures once the court order requiring them is dismissed. Our previous decisions make clear that a case does not become moot simply because a court order redressing the alleged grievance has been obeyed. NLRB v. Raytheon Co., 398 U. S. 25 (1970); NLRB v. Pennsylvania Greyhound Lines, Inc., 303 U. S. 261, 271 (1938). In United States v. W. T. Grant Co., 345 U. S. 629 (1953), on which the court below relied and which the Court today attempts to distinguish, it was stated:
“Both sides agree to the abstract proposition that voluntary cessation of allegedly illegal conduct does not deprive the tribunal of power to hear and determine the case, i. e., does not make the case moot. United States v. Trans-Missouri Freight Assn., 166 U. S. 290 (1897); Walling v. Helmerich & Payne, Inc., 323 U. S. 37 (1944); Hecht Co. v. Bowles, 321 U. S. 321 (1944). A controversy may remain to be settled in such circumstances, United States v. Aluminum Co. of America, 148 F. 2d 416, 448 (1945), e. g., a dispute over the legality of the challenged practices. Walling v. Helmerich & Payne, Inc., supra; Carpenters Union v. Labor Board, 341 U. S. 707, 715 (1951). The defendant is free to return to his old ways. This, together with a public interest in having the legality of the practices settled, militates against a mootness conclusion. United States v. Trans-Missouri *644Freight Assn., supra, at 309, 310. For to say that the case has become moot means that the defendant is entitled to a dismissal as a matter of right, Labor Board v. General Motors Corp., 179 F. 2d 221 (1950). The courts have rightly refused to grant defendants such a powerful weapon against public law enforcement.
“The case may nevertheless be moot if the defendant can demonstrate that There is no reasonable expectation that the wrong will be repeated.’ The burden is a heavy one. Here the defendants told the court that the interlocks no longer existed and disclaimed any intention to revive them. Such a profession does not suffice to make a case moot although it is one of the factors to be considered in determining the appropriateness of granting an injunction against the now-discontinued acts.” Id., at 632-633 (footnotes omitted; emphasis supplied).7
In my view, there is far less to the mootness issue here than to that presented in W. T. Grant Go. Petitioners, the subject of the lower court’s injunction, hotly dispute any suggestion that no live issues remain. Furthermore, they did not cease voluntarily their allegedly illegal conduct and have not disclaimed an intention to resume their use of civil service tests as a primary hiring criterion.8 Nor, in light of this *645record, could a disclaimer — were it made — satisfy the “heavy burden” imposed upon a defendant seeking to have a suit dismissed as moot.9
*646Furthermore, the Court’s avoidance of the merits of this controversy by its novel view of mootness leaves the county in a quandary. Although it is not unreasonable to assume, following dismissal of this suit as moot, that the county will again base hiring on unvalidated aptitude tests, it also is possible that the county may believe that hiring procedures of the sort previously required by the order under review are necessary to ensure compliance with federal law. The Court’s disposition today will leave the decision of the Court of Appeals on the merits as the most pertinent statement of the governing law, even if that decision is not directly binding.10 Therefore, any future litigation against the county, including the suit to assert the rights of pre-1971 applicants that the Court seems to contemplate, ante, at 630 n. 3, is likely to be controlled by the decision of that court.
In sum, the Court’s disposition leaves all of the parties in positions of uncertainty: Respondents lack protection against the resumption of the county’s alleged discrimination, and the county lacks a conclusive determination of the legality of its conduct. All of these considerations militate against a determination of mootness. See Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., 435 U. S. 519, 535-537, n. 14 (1978). Accordingly, I conclude that the question of whether petitioners violated § 1981 is before *647us.11 I would reach this issue and determine whether § 1981, like the Equal Protection Clause of the Fourteenth Amendment, prohibits only purposefully discriminatory conduct.12
The complaint also alleged that Fire Department personnel had engaged in nepotistic and "word-of-mouth" recruitment, employed a discriminatory interview procedure, used other procedures, practices, and standards that disfavored minorities,,-and refused to take affirmative action to correct the effects of past discrimination. App. 4-5. The District Court found that the written tests and the Department’s failure to take affirmative steps to overcome a reputation of discrimination among blacks and Mexican-Americans constituted illegal discrimination, but held that the use of a 5'7" height requirement for firemen was job related and not discriminatory. Id., at 39. The opinion of the Court of Appeals relied *638entirely on the county’s written examinations as the basis for sustaining the District Court’s remedial order. 566 F. 2d 1334, 1342-1344 (1977).
In addition, the Court of Appeals reversed as clearly erroneous the finding that the height requirement was job related and suggested that the District Court could take further steps to offset the allegedly discriminatory effect of this standard. Id., at 1341-1342, 1343. Petitioners have not sought review of that question; rather they contend that the court below applied the wrong legal standards in assessing generally the legality of their employment practices.
The order required the county to select a minimum of 20% of its new firemen from black applicants and another 20% from Mexican-American applicants until the percentage of members of these racial groups in the fireman work force equaled the percentages in the general population of the county. The county also was required to file annual reports with the court on fireman hiring.
A stipulation signed by the parties in the District Court incorrectly stated that the change in plans took place on January 8, 1972. It is clear from the face of the stipulation, however, that the 1973 date was meant: The county could not have scheduled interviews to take place on or after January 3, 1972, on the basis of a test administered some time in January 1972. No party has contended here that the 1972 date was correct.
According to the stipulated facts, 19.8% of the applicants who took the 1972 test were black or Mexican-American, but only 8.9% of those 544 applicants who initially were scheduled for interviews were minority group members.
Mr. Justice Stewart agrees that the case is not moot, but argues that the § 1981 issue is not properly presented in this case. He thinks the court below also rested its holding on a finding that petitioners’ conduct violated Title VII of the Civil Rights Act of 1964. While the matter is not free from doubt, it seems most unlikely that the court below based its affirmance of the District Court’s sweeping injunction on its cryptic and offhand conclusion that “[o]f course” the “continued threat” to base hiring on test performance “is admittedly a violation of Title VII,” 566 F. 2d, at 1341 n. 14. As the language quoted in the text illustrates, the court grounded its decision expressly on § 1981. The one-sentence reference to Title VII is divorced from any discussion of the relationship between the purported violation and the relief granted. Although the basis of the court’s affirmance of the injunction is not clear, see 566 F. 2d, at 1342-1344, it apparently believed the District Court properly took into account pre-Title VII violations of § 1981 in determining the scope of the remedial order, in spite of respondents’ lack of standing to seek relief for themselves. Thus, the decision of the Court of Appeals seems to have been based on a conclusion that independent violations of § 1981 had occurred'.
Petitioners challenged the standing of respondents to seek the relief that was granted. The court below rejected this challenge in part, holding that respondents could attack the threatened use of the 1972 test. 566 F. 2d, at 1338 n. 6; id., at 1347 n. 2 (Wallace, J., dissenting). The Court approves this holding today. Ante, at 631. I agree that respondents alleged injuries in fact, and sought relief, adequate to meet our standing requirements, even though they lacked standing to seek all of the relief accorded them by the courts below. See Nyquist v. Mauclet, 432 U. S. 1, 6 n. 7 (1977); Arlington Heights v. Metropolitan Housing Dev. Corp., 429 U. S. 252, 261-264 (1977); Simon v. Eastern Kentucky Welfare Rights Org., 426 U. S. 26, 41-42 (1976); Warth v. Seldin, 422 U. S., at 498-502; Linda R. S. v. Richard D., 410 U. S., at 617. Cf. East Texas Motor Freight Systems, Inc. v. Rodriguez, 431 U. S. 395, 404 (1977).
As we further observed in United States v. Oregon State Medical Soc., 348 U. S. 326, 333 (1952), “[i]t is the duty of the courts to beware of efforts to defeat injunctive relief by protestations of repentance and reform, especially when abandonment seems timed to anticipate suit, and there is probability of resumption.”
Los Angeles, along with the city of San Diego, filed an amicus brief in a case before this Court which involved personnel testing. In their statement of interest, these amici declared:
“The Cities of Los Angeles and San Diego are municipal corporations within the State of California. The interests of those cities arise from their positions as public sector employers which have charter requirements to hire individuals based on merit. Pursuant to merit principles, both *645cities use various personnel tests to hire and to promote individuals in the classified civil service.
“Thus, both cities before this Court as Amici Curiae have interests in maintaining personnel testing programs to fulfill the merit sj^stem requirements of their municipal charters, as well as interests in sustaining those personnel tests in litigation.” Brief for City of Los Angeles et al. as Amici Curiae in Detroit Edison Co. v. NLRB, O. T. 1978, No. 77-968, pp. 2, 4.
The assertion of the Court that “there can be no reasonable expectation” that petitioners will base hiring on unvalidated aptitute tests, ante, at 631, lacks any record support and is contrary to the assumptions upon which the courts below based their actions. There has been no change in circumstances of any relevance to the Court’s conclusion since petitioners attempted to use their unvalidated 1972 test as a hiring device. Title VII, which the Court appears to suggest as an intervening factor, applied with full force to petitioners when in January 1973 they sought to limit hiring to applicants with the highest scores on the 1972 test. Under W. T. Grant Co., the burden is on petitioners to demonstrate that there is little chance they will resume their allegedly illegal conduct. Petitioners have not attempted to meet that burden here. The Court’s assumption that in the future the county will seek to validate its tests before relying on them not only is unsubstantiated by the record facts, it also reverses the presumption we normally apply in mootness cases. See, e. g., Hampton v. Mow Sun Wong, 426 U. S. 88, 98, and n. 14 (1976) (federal agency’s new hiring regulation forbidding chaEenged practice does not moot claim for injunctive and declaratory relief).
It is instructive to compare the facts of this case with those of DeFunis v. Odegaard, 416 U. S. 312 (1974). Here petitioners have made no change in their hiring procedures except in response to the court order, and have put on this record no evidence that they contemplate any further changes. The Court’s belief that petitioners will not resume their use of unvalidated tests rests solely on speculation. In DeFunis, by contrast, the law school had admitted DeFunis to his final quarter in school and represented to this Court that it would make no attempt to rescind this registration. Unlike the case at bar, DeFunis had not brought a class action; hence only his individual right not to be discriminated against in law school admissions was at stake. Id., at 317. Because it was virtually certain *646that DeFunis never again would need to submit to the admission process he challenged, we held that the case had become moot. Id.., at 318. Even the very slight chance that DeFunis might not receive his degree was considered sufficiently substantial by four Members of the Court to render the ease a live controversy.
Although a decision vacating a judgment necessarily prevents the opinion of the lower court from being the law of the ease, O’Connor v. Donaldson, 422 U. S. 563, 577-578, n. 12 (1975); A. L. Mechling Barge Lines v. United States, 368 U. S. 324, 329-330 (1961); United States v. Munsingwear, Inc., 340 U. S. 36 (1950), the expressions of the court below on the merits, if not reversed, wiE continue to have precedential weight and, until contrary authority is decided, are likely to be viewed as persuasive authority if not the governing law of the Ninth Circuit.
I cannot agree with MR. Justice Stewart that the question whether petitioners had violated § 1981 in the past was a matter of indifference to the court below and would be immaterial upon remand. See n. 5, supra. In exercising its “broad” equitable discretion as to granting any prophylactic relief, see United States v. W. T. Grant Co., 345 U. S. 629, 633 (1953), the District Court could consider whether the county’s conduct was a single, isolated instance of illegality or part of a pattern of unlawful conduct. This would rest on a determination of the requirements of § 1981 prior to the 1972 amendment of Title VII. Thus, a decision now on the § 1981 issue could affect the substantial rights of the parties and would not be an advisory opinion.
I am in agreement with Mr. Justice Stewart that, regardless of the proper construction of § 1981, the only arguably illegal conduct in this case could not justify the sweeping remedy ordered by the District Court.