COLE, J., delivered the opinion of the court, in which KEITH, J., joined. BATCHELDER, J. (pp. 414-29), delivered a separate opinion concurring in part and dissenting in part.
OPINION
COLE, Circuit Judge.Defendants, Local Union 496, Laborers’ International Union of North America (“Local 496”), Floyd Conrad, and Laborers’ International Union of North America (“LIUNA”), appeal the district court’s order finding them liable for race discrimination in violation of Title VII of the Civil Rights Act of 1964, 42 U.S.C. §§ 2000e-2(a) and (c), and 42 U.S.C. § 1981.
Plaintiffs, all African-American persons who sought membership in Local 496 or referral for jobs at the Perry Nuclear Power Plant (“Perry”), cross-appeal the district court’s order calculating damages and its order sanctioning plaintiffs’ counsel for alleged failure to comply with LIU-NA’s discovery requests.
For the following reasons, we AFFIRM the judgment of the district court with respect to the defendants’ appeal and AFFIRM the judgment of the district court with respect to the plaintiffs’ cross-appeal.
*400I. BACKGROUND
The facts in this case implicate the relationship among the plaintiffs, Local 496, LIUNA, and Perry, where members of the plaintiff class sought employment. All plaintiffs, including the named plaintiff, Davine Alexander, were black applicants whom Local 496 rejected for membership.
Work began at Perry, which is located in Lake County, Ohio, in the early 1970s. In 1973, Local 4961 signed a project labor agreement with the Cleveland Electric Illuminating Company, under which Local 496 was to act as the exclusive hiring hall for laborers at Perry during the plant’s “construction phase,” which lasted until 1986. During this time, Perry was the primary employer of laborers in Lake County. However, Perry by no means exclusively employed laborers who resided in Lake County; laborers from several neighboring counties also coveted work at the plant, in large measure because of the relatively high wages Perry contractors offered. Perry laborers earned approximately $14.00 per hour, compared to the average $6.66 an hour other workers, including those in professional occupations, earned in the same geographic area.
Local 496’s membership has always been overwhelmingly white. For example, between 1980 and 1986 blacks comprised only between 2.88% and 8.59% of its total membership. During this same time period, the union accepted 54 new members, only one of whom was black.2 African Americans who sought a referral to Perry from this union faced daunting opposition. According to the project labor agreement, Local 496 was to refer both union members and non-members for laborers’ positions at Perry. It failed to do so. Furthermore, Local 496’s constitution, which is the Uniform Local Constitution of the Laborers’ International Union of North America, requires that a person seeking union membership first be employed as a laborer in Lake County. This “working-in-the-calling” rule requires non-members seeking induction into Local 496 to first secure work at a “union shop.” Conversely, in the event that an individual secured such work, he or she was required to join the union within eight days of beginning employment. Essentially, then, the project labor agreement, which obligated Local 496 to treat members and non-members alike for the purposes of referrals, was to constitute a contractual waiver of the working-in-the-calling rule. Unfortunately for the plaintiffs, despite this waiver, union personnel selectively enforced the working-in-the-calling rule to effect the exclusion of black prospective members. Most markedly between 1975 and 1985, a period of rapid union growth, Local 496 regularly waived the working-in-the-calling requirement for white applicants. The union declined to accord African-American applicants the same benefit. Indeed, Floyd Conrad, business manager of Local 496, admitted that the union failed to refer a single black non-member to Perry.
The white applicants for whom the union waived its working-in-the-calling rule were, more often than not, relatives of Local 496 members. During the relevant time period, over 30% of union members had relatives who were also union members. Moreover, one of the principal means of acquiring Local 496 membership or an employment referral from the union was the request of a relative or friend who was already a union member. Sometimes, union members asked the union’s business manager for a waiver of the working-in-the-calling rule on behalf of their cronies. *401Alternately, union members working as stewards or foremen at Perry simply approached employers and contractors at the plant and recommended their relatives for available positions. This sort of direct access to Perry employers was only available to people already employed at the plant, because of the plant’s security requirements.
The ease with which white members of Local 496 bolstered their ranks with friends and relatives contrasts starkly with the barriers their black counterparts confronted when they sought to act similarly. On several occasions, Donald Robinson, one of the few African-American members of Local 496, attempted to refer black friends and relatives to Conrad for positions at Perry. Conrad consistently ignored Robinson’s requests. The story of Cheryl Journigan, a class member and relative of Donald Robinson’s, illustrates Conrad’s treatment of black applicants. Journigan testified that in 1985, she repeatedly sought union membership or employment referrals by calling and appearing at Local 496’s union hall. Journigan recalled that Conrad invariably refused to return her telephone calls or instructed union secretaries to tell Journigan he was absent. Deborah Bracale, Conrad’s secretary at the time, corroborated Journigan’s account. At Conrad’s direction, union personnel similarly rebuffed other African Americans seeking union membership or employment referrals. Thus, several factors, including nepotism, inequitable application of the working-in-the-calling-rule, and security at Perry, all converged to exclude black applicants from union membership and employment referrals.
After the plant’s construction phase ended, maintenance work at the plant began. This work was performed pursuant to a 1985 National Maintenance Agreement, which LIUNA signed but Local 496 did not. However, the Maintenance Agreement provided that Local 496 was to act as LIUNA’s agent in filling all laborer vacancies at Perry. No LIUNA representatives or agents were involved in administering the referral system.
After a decade of unsuccessful attempts to thwart the union’s discriminatory membership restrictions, several black applicants initiated this class action in December 1984. Subsequently, by orders dated October 28, 1985 and March 6, 1986, individual discrimination suits filed by plaintiffs Ron Colvin, Richard Lilly, Edward Turner II, Percy Pouewells, Lee Coffee, Sr., Isiah Johnson, Jr., and Jimmie Rice, against Local 496 and Conrad were consolidated with the class suit. Cheryl Journi-gan, the last class member to file EEOC charges of discrimination against the defendants, did so on January 10, 1985. On January 26, 1988, the district court certified the class to include:
All Black persons who, on or before [January 26, 1988], have sought membership in Local 496 and/or employment either by application or by referral under the policy described in the collective bargaining agreement of March 9, 1973, by which the defendant union agreed to make referrals to employers at the Perry Nuclear Power Plant site.
LIUNA was aware of this action from its inception. Beginning in 1984, Business Agent Conrad regularly informed the regional office of LIUNA, specifically LIU-NA’s Regional Manager, Thomas J. Arcon-ti, about charges lodged with the Equal Employment Opportunity Commission (“EEOC”), lawsuits filed by the plaintiffs, and of all findings of the EEOC related to the allegations against the local union. LIUNA’s regional officers, the EEOC and the National Labor Relations Board, in turn, notified the General President of LI-UNA of such events. In addition, the constitutions of Local 496 and LIUNA empowered LIUNA to intervene in the affairs of Local 496. Nevertheless, LIUNA never investigated the plaintiffs’ charges of discrimination. Having discovered LIUNA’s awareness of their EEOC charges against Local 496, in September 1989, plaintiffs Colvin and Tomblin filed additional EEOC *402charges against the parent union, claiming it intentionally refused to investigate the alleged discrimination. On January 12, 1990, the class moved to amend its complaint to add LIUNA as a defendant. Although the suit was originally to be tried on January 17, 1990, the district court found that LIUNA was an indispensable party and on January 19, 1990, accordingly granted the plaintiffs leave to amend their complaint. On January 22, 1990, Tomblin and -Colvin filed amended EEOC charges of discrimination, again alleging that LIU-NA had intentionally neglected to investigate their charges of discrimination against the other defendants. After Col-vin received his EEOC right-to-sue letter, the plaintiffs filed their amended complaint, adding LIUNA as a defendant, on March 30,1990.
After protracted preliminary proceedings, the plaintiffs had their day in court. The trial was bifurcated, first to determine the issue of liability, and then, if the district court found the defendants liable, to ascertain the amount of damages. A bench trial determining liability took place in the spring of 1991. On December 10, 1991, the district court found' the defendants liable for both disparate treatment and disparate impact racial discrimination, in violation of Title VII and § 1981. Specifically, the district court found that as a result of the discriminatory application of its facially neutral membership requirements, Local 496 refused African Americans union membership in violation of federal civil rights law. The district court also determined that in order to deter black applicants and “keep Local 496 mainly an all white union[,]” African Americans applying for membership into Local 496 “were met with a reluctant or even, at times, hostile attitude of [Floyd Conrad].” In addition, the district court concluded that LIUNA was liable for Local 496’s discriminatory practices because the local union acted as its parent’s agent, and the international union breached its affirmative duty to ensure the local’s compliance with federal civil rights law. During the damages trial in 1996, the parties reached a partial settlement. Local 496 agreed to an initial payment of $100,000, and LIUNA agreed to an initial payment of $200,000. The parties also agreed to a system by which Local 496 would give plaintiffs preference in employment referrals. Whether the plaintiffs receive any additional sum depends on the outcome of this appeal. Following a hearing, the district court approved the settlement in June 1996. This timely appeal followed.
II. ANALYSIS
A. Defendants’ Appeal
1. Disparate Treatment Liability
The defendants first argue that the district court erred in determining that they unlawfully subjected the plaintiffs to disparate treatment because of their race. This court reviews a district court’s finding of facts made after a bench trial for clear error and reviews a district court’s conclusions of law de novo. See Davies v. Centennial Life Ins. Co., 128 F.3d 934, 938 (6th Cir.1997). When reviewing for clear error, we must affirm the trial court unless we are left with the definite and firm conviction that a mistake has been committed. See EEOC v. Atlas Paper Box Co., 868 F.2d 1487, 1493 (6th Cir.1989) (citation and quotation omitted).
A plaintiff may create a presumption of discrimination pursuant to the McDonnell Douglas burden-shifting principle. See McDonnell Douglas Corp. v. Green, 411 U.S. 792, 803, 93 S.Ct. 1817, 36 L.Ed.2d 668 (1973). Under the McDonnell Douglas framework, a plaintiff bears the burden of establishing by a preponderance of the evidence a prima facie case and creating a presumption of discrimination by demonstrating: (1) membership in the protected class; (2) that he or she suffered from an adverse action; (3) that he or she was qualified for the position; and (4) that he or she was treated differently from similarly situated members of the unpro*403tected class. See Mitchell v. Toledo Hosp., 964 F.2d 577, 582-83 (6th Cir.1992) (citing McDonnell Douglas, 411 U.S. at 803); see also Hartsel v. Keys, 87 F.3d 795, 800 (6th Cir.1996). Once the plaintiff establishes a prima facie case, a defendant may offer any legitimate, non-discriminatory reason for the action, which the plaintiff may then rebut with evidence of pretext; however, the burden of proof at all times remains with the plaintiff. Hartsel, 87 F.3d at 800. (citing St Mary’s Honor Ctr. v. Hicks, 509 U.S. 502, 113 S.Ct. 2742, 125 L.Ed.2d 407 (1993)).
In this case, the district court found that pursuant to the McDonnell Douglas framework, the plaintiffs demonstrated that the defendants subjected them to racially based disparate treatment. First, the district court determined that the plaintiffs established a prima facie case by showing that: (1) they are black; (2) they were available for referral by the union for job opportunities at Perry; (3) Local 496 did not refer plaintiffs for employment opportunities at Perry; and (4) white non-union members were referred for work and made members of Local 496, during the same time plaintiffs had applied and been refused.
We agree. Floyd Conrad selectively enforced, to the detriment of black applicants, the Uniform Constitution’s working-in-the-calling requirement. Conrad testified that white union members asked him “a thousand times or more” to admit unemployed relatives to Local 496, and that he obliged them; he also testified that he had admitted into the union his own unemployed relatives, including his father.3 During the same time period, when Donald Robinson advised several unemployed African Americans to seek membership in Local 496, Conrad refused them all.4 Moreover, at trial, Conrad admitted that whenever a contractor specifically requested that Local 496 refer a black person for employment, Conrad would call Local 860 of Cleveland, which had a higher percentage of African-American members than Local 496, to suggest that the Cleveland union refer one of its members. Conrad thereby avoided referring for employment, and subsequently admitting into Local 496, any African-American applicants.
Furthermore, African Americans suffered disparate treatment with regard to Local 496’s Perry referral policy itself; after the union changed its Perry referral policy in 1987, it failed to make this change known to black applicants, effectively ensuring that they would not be referred. Prior to 1987, Local 496 did not have a written referral policy for Perry; however, it admits that it only referred members to Perry, in contravention of the project labor agreement. Local 496’s practice was to allow members and, occasionally, nonmembers to sign a notebook located in the union indicating that they wished to be referred. Conrad would then compile a master list from the notebook containing the names of members only. This practice led to National Labor Relations Board charges against Local 496 and eventually *404to the written 1987 referral policy. Pursuant to the new policy, Local 496 maintained a single list of both members and non-members wishing to be referred to Perry. Local 496 made referrals from this list, in order. However, persons on the list were required to inform Local 496 monthly that they remained unemployed and interested in Perry. Otherwise, their names were removed from the referral list. Although this policy was facially neutral, Conrad did not inform class members of the new procedure. Members, however, were informed via posters hung in locations throughout the union hall to which only members had access. Consequently, class members’ names were not retained on the union’s referral list, and Local 496 never referred any for employment under this new policy.
For example, on or about January 22, 1990, plaintiffs Art Tomblin and Ronald Colvin appeared at Local 496’s hiring hall seeking referral for employment. Pursuant to the October 1987 referral policy, the union representative asked Colvin and Tomblin to sign their names on the out-of-work list. They were 92nd and 93rd on the list at the time they signed up. On February 1, 1990, the union secretary prepared a new out-of-work list and deleted the names of the individuals on the January list who had received referrals for employment or had failed to notify Local 496 of their continued interest in a referral within the last thirty days. As a result of these deletions, Colvin and Tomblin advanced to positions 66 and 66 on the list. However, the union secretary responsible for preparation of the March 1990 out-of-work list dropped Colvin and Tomblin from the roster because they had failed to notify Local 496 of their continuing interest in referral for employment. According to the defendants, had Colvin and Tomblin indicated their continued interest, they would have remained on the roster, and been referred for work in May of 1992. Moreover, the defendants argue that they informed plaintiffs’ counsel of the new referral policy, and, thus, by association informed the plaintiffs.
Defendants suggest that Link v. Wabash R. Co., 370 U.S. 626, 82 S.Ct. 1386, 8 L.Ed.2d 734 (1962), supports their proposition that the knowledge of a litigant’s counsel is imputed to the litigant. However, there are exceptions to this rule when, as here, equity requires such. See Partlow v. Jewish Orphans’ Home of Southern Cal, 645 F.2d 757, 758-62 (9th Cir.1981). Quite frankly, we find it peculiar that although Local 496 supposedly implemented the new referral policy for the purpose of curing the previous policy’s defects, the defendants never directly apprised African Americans seeking employment of the new referral system. Common sense dictates that if the defendants really intended to make employment opportunities available to all, they would have, as Magistrate Judge Hemann stated, “implemented this desire by making the new referral rules readily available and/or made at least one telephone call to prospective workers.” This is particularly true given Conrad’s admission that he failed to refer a single non-member minority to work at Perry. In this case, the defendants’ notice to plaintiffs’ counsel of the facially neutral referral system does not absolve defendants of their continued discriminatory application of that system. Thus, we . decline to extend the holding of Link to this case.
Incidentally, the record contains still more evidence supporting the district court’s conclusion that plaintiffs made out a prima facie case. Conrad, in fact, blatantly displayed his personal hostility toward African Americans on several occasions. Don Robinson and Rudy Bracale, another member of Local 496, both testified that Conrad referred to Robinson by a racial epithet on at least two occasions. See Ercegovich v. Goodyear Tire & Rubber Co., 154 F.3d 344, 354 (6th Cir.1998) (recognizing that discriminatory remarks of decisionmakers are relevant to show motivations for their actions); Talley v. *405Bravo Pitino Restaurant, Ltd., 61 F.3d 1241, 1248 (6th Cir.1995) (recognizing that employer’s repeated use of racial epithets constituted direct evidence of racial discrimination). Furthermore, after Robinson began questioning Local 496’s discriminatory practices, Conrad retaliated by removing Robinson from his position as union steward “because he was bringing up minority stuff that was not his business.” Taken as a whole, we view the above as undeniable evidence of racial animus and disparate treatment and accordingly affirm the district court’s conclusion that the plaintiffs established a prima fa-cie case.
Once the plaintiff establishes a prima facie case of discrimination, the defendant may respond by articulating a legitimate, non-discriminatory reason for its action. Hartsel, 87 F.3d at 799. In this case, the defendants claim that the business purpose for their workingrin-thecalling policy was to protect unemployed union members from an influx of unemployed non-members attempting to join the union. The district court found this reason to be pretext for discrimination, and the record supports the district court’s conclusion. Quite simply, the defendants selectively enforced the working-in-the-calling requirement. As we have previously discussed, Conrad testified that he often admitted unemployed relatives of white union members. The fact that the defendants offered union membership to unemployed white nonmembers while they refused membership to African-Americans, even those who had been offered employment, plainly suggests that Conrad was less concerned with applicants’ employment status than he was with their race. This evidence negates the defendants’ proffered reason for refusing African-American applicants union membership, and the plaintiffs have thus met their burden of establishing pretext. See Manzer v. Diamond Shamrock Chemicals Co., 29 F.3d 1078, 1084 (6th Cir.1994) (recognizing that showing that the proffered reason did not actually motivate the defendant is sufficient to establish pretext).
The district court’s conclusion with regard to disparate treatment was not clearly erroneous. To the contrary, we are hard-pressed to imagine a race-discrimination case with more explicit evidence of disparate treatment. We accordingly affirm the district court’s conclusion that the defendants engaged in racially based disparate treatment in violation of Title VII.
2. Disparate Impact Liability
The defendants argue that the district court erred in finding that the union’s facially neutral policies had a disparate impact upon the plaintiffs, in violation of Title VII of the Civil Rights Act of 1964. The challenged practices are: (1) Local 496’s working-in-the-calling rule; and (2) its practice of referring only union members for employment. The district court found that the plaintiffs presented statistical evidence sufficient to establish a prima facie case of disparate impact discrimination. The district court also determined that the defendants produced no job-related business justification for the policies engendering the disparate impact. We review a district court’s finding of disparate impact discrimination for clear error. See Atlas Paper, 868 F.2d at 1493.
It is now well-settled that Title VII of the Civil Rights Act of 1964, 42 U.S.C. § 2000e et seq., proscribes both overt discrimination as well as “practices that are fair in form but discriminatory in operation.” Griggs v. Duke Power Co., 401 U.S. 424, 431, 91 S.Ct. 849, 28 L.Ed.2d 158 (1971). The plaintiffs burden in a Title VII disparate impact case is to prove that a particular employment practice has caused a significant adverse effect on a protected group. See Wards Cove Packing Co. v. Atonio, 490 U.S. 642, 657, 109 S.Ct. 2115, 104 L.Ed.2d 733 (1989); Scales, 925 F.2d at 908 (citing Watson v. Fort Worth Bank & Trust Co., 487 U.S. 977, 108 S.Ct. 2777, 101 L.Ed.2d 827 (1988)). Once *406the plaintiff establishes the adverse effect, the burden shifts to the employer to produce evidence that the challenged practice is a business necessity. See Wards Cove, 490 U.S. at 659.
Here, the defendants’ principal argument is that the testimony of plaintiffs’ expert, Brian Pendleton, Ph.D., was based on an overly broad labor pool and that as a result the district court erred in crediting his evidence over that of defense expert, Beth Martin, Ph.D. Dr. Pendleton based his statistics on a labor pool comprised of Lake, Ashtabula, Cuyahoga and Geauga Counties. The experts agreed that 93.5% of Local 496’s membership came from these four counties. Dr. Pendleton’s calculations led him to conclude that the percentage of African Americans in Local 496, approximately 5%, was two standard deviations lower than the percentage of African Americans in the four-county labor pool. Dr. Martin, on the other hand, based her statistics on a labor pool comprised only of the people employed in Lake County, where Perry is located. She narrowed her labor pool to this population based on her reasoning that Local 496’s jurisdiction is limited to people employed in Lake County, regardless of their county of residence. Dr. Martin then determined that the percentage of African Americans in the relevant labor pool in Lake County and the number of black members of Local 496 both equaled 5%. Relying on this statistic, Dr. Martin reasoned that Local 496’s African-American membership mirrored the African-American population in the relevant labor market and, on this basis, concluded that the union’s policies had no disparate impact on the plaintiffs.
The district court found that the labor pool upon which Dr. Pendleton based his conclusion was overly broad, while Dr. Martin’s was overly narrow. The district court nevertheless concluded that the “statistical disparities” were sufficient to establish a prima facie case of disparate impact discrimination. The district court reasoned that the union’s membership and referral policies, characterized by the facially neutral working-in-the-calling rule and the policy of referring only union members for employment, “even if applied in a non-discriminatory fashion ... simply works to reinforce past patterns of discrimination.”
We agree. An an initial matter, we note that despite whatever reservations the district court may have had with Dr. Pendleton’s report, its determination of the “four-county area” as the correct labor pool was not clearly erroneous. The evidence in the record indicates that Perry paid extremely high wages for relatively low-skill positions. Therefore, applicants were exceedingly willing to commute from throughout the area to Perry. As the district court stated, then, “the gross disparity between the percentage of blacks in the membership of Local 496 and the four-county area” certainly supports a prima facie case. Moreover, we recognize that plaintiffs who present a statistical analysis of some challenged practice need not rule out all other variables to prevail. See United States v. City of Warren, 138 F.3d 1083, 1094 (6th Cir.1998) (citation omitted); see also Bazemore v. Friday, 478 U.S. 385, 400, 106 S.Ct. 3000, 92 L.Ed.2d 315 (1986) (“A plaintiff in a Title VII suit need not prove discrimination with scientific certainty; rather his or her burden is to prove discrimination by a preponderance of the evidence.”). The fact that Local 496 maintained policies that limited the union’s membership to people who were employed in Lake County, whose workforce was 99% white, necessarily had a disparate impact on unemployed African Americans seeking membership in, or employment referrals from, the union. Put differently, the overwhelming majority of workers eligible for union membership were white, in large measure because the union’s own discriminatory practices prevented African Americans from obtaining employment in Lake County; Local 496’s membership reflected this demographic, resulting in the de facto exclusion of African Americans from union *407membership. See Ingram v. Madison Square Garden, 709 F.2d 807, 810-11 (2d Cir.1983) (affirming district court’s finding that union’s referral policies violated Title VII based on a combination of a few statistics and evidence that behavior of union personnel discouraged plaintiffs from seeking employment); see also Gibson v. Local 40, Supercargoes and Checkers of the Int’l Longshoremen’s and Warehousemen’s Union, et al., 543 F.2d 1259, 1268 (9th Cir.1976) (stating that union’s preference in referring relatives of union members when membership was overwhelmingly white had disparate impact in violation of Title VII even if defendants’ nepotism was without discriminatory intent).
Once a plaintiff establishes that a particular practice has engendered a significant adverse effect, the defendant must produce evidence that the challenged practice is a business necessity. See Wards Cove, 490 U.S. at 659; Warren, 138 F.3d at 1091-92. Again, the defendants argue that their membership and referral policies, particularly the working-in-the-calling rule, were implemented to protect union members from competing for available positions with an influx of unemployed applicants. The district court correctly determined that this explanation does not justify the discriminatory effects of the challenged practices. Because, as explained above, Local 496 is the sole source of referrals for Perry and, in theory, it offered membership only to people employed in Lake County, its own practices served to reinforce the discriminatory impact on African Americans seeking employment at Perry, first by excluding them from union membership and then by refusing to refer them for jobs because they are non-members. Such a business justification, which buttresses established forms of discrimination, cannot withstand a Title VII challenge. See United States v. Bethlehem Steel Corp., 446 F.2d 652, 659 (2d Cir.1971) (holding that employer’s facially neutral practices which perpetuated effects of employer’s prior discrimination violated Title VII); see also Warren, 138 F.3d at 1094 (stating that defendant employer should not escape liability because it maintained two discriminatory practices which operated concurrently to exclude black applicants); Gibson, 543 F.2d at 1267 (invalidating practice that operated to freeze the status quo of the defendant’s discriminatory employment practices).
Based on the evidence in the record, the district court correctly concluded that the plaintiffs established a prima facie disparate impact claim, and the defendants’ proffered justification was pretext for discrimination. We therefore affirm the district court’s finding of liability with regard to the plaintiffs’ disparate impact claim.
3. LIUNA’s Liability
a. Statute of Limitations
LIUNA contends that the district court erred for a number of reasons by allowing plaintiffs’ claims against it to proceed. First, LIUNA suggests that claims against it are barred by the statute of limitations governing Title VII claims.
Generally, the timely filing of a charge of discrimination with the EEOC is a condition precedent to a Title VII lawsuit. See Atlas Paper Box, 868 F.2d at 1495. Usually, if the alleged discrimination occurred more than 180 days prior to the plaintiffs filing of an EEOC charge, claims implicating these actions are barred. See id. However, if the alleged unlawful practice occurs in a “deferral state,” in this case Ohio, which has enacted its own laws prohibiting discrimination in employment, the plaintiff must file suit within 300 days of the alleged discriminatory act. See 42 U.S.C.. § 2000e-5(e); EEOC v. Fenton Indus. Pub. Co., 851 F.2d 835, 837 n. 5 (6th Cir.1988).
In this case, plaintiff Ronald Colvin first filed an EEOC charge against LIUNA on September 7, 1989. From this filing date, the 300-day statute of limitations applicable to Title VII actions filed in deferral *408states normally would preclude consideration of alleged violations occurring prior to November 11, 1988. Based on this chronology, LIUNA argues that none of the allegedly discriminatory acts occurring before this date supports a finding of liability against it. Because we conclude that the defendants, including LIUNA, are guilty of a continuing violation, as explained below, this argument is unavailing.
This court has long recognized that an ongoing, continuous series of discriminatory acts may be challenged if one of those discriminatory acts occurred within the limitations period. See, e.g., Haithcock v. Frank, 958 F.2d 671, 677 (6th Cir.1992); see also Dixon v. Anderson, 928 F.2d 212, 216 (6th Cir.1991). “If a continuing violation is shown, a plaintiff is entitled to have a court consider all relevant actions allegedly taken pursuant to the employer’s discriminatory policy or practice, including those that would otherwise be time barred.” Van Zant v. ELM Royal Dutch Airlines, 80 F.3d 708, 713 (2d Cir.1996). We view continuing violations as falling into two categories of narrowly limited exceptions to the usual rule that statutes of limitations are triggered at the time the alleged discriminatory act occurred. See Haithcock, 958 F.2d at 677. The first category of continuing violations arises “where there is some evidence of present discriminatory activity giving rise to a claim of a continuing violation; that is where an employer continues presently to impose disparate work assignments or pay rates between similarly situated groups.” Dixon, 928 F.2d at 216. However, “at least one of the forbidden discriminatory acts must have occurred within the relevant limitations period.” Id. The second category of continuing violations arises “where there has occurred a longstanding and demonstrable policy of discrimina-tion_ Unrelated incidents of discrimination will not suffice to invoke this exception; rather there must be a continuing over-arching policy of discrimination.” Id. at 217 (internal quotations omitted).
The facts in this case clearly support the district court’s conclusion that the defendants are liable regardless of the statute of limitations because their actions were part of a continuing violation. Floyd Conrad testified that over a significant period of time, he refused African Americans membership in Local 496 based on the working-in-the-calling rule. The district court found that this practice continued at least through January 1990. Also as late as January 1990, Local 496’s personnel failed to apprise African-American nonmembers of the procedure necessary to maintain their eligibility for employment referrals, though the union’s overwhelmingly white membership was informed of the relevant procedure. Further, Floyd Conrad’s testimony supports a finding that although the official membership and referral policies of Local 496 may have changed over the years, the practice of excluding black applicants continued into the relevant limitations period. Moreover, the working-in-the-calling rule, memorialized in Local 496’s constitution and bylaws, resulted in the de facto exclusion of African Americans from the ranks of Local 496 as well as from employment at Perry. Thus, the defendants committed both types of continuing violations recognized by this court: a series of related discriminatory acts and an established policy of discrimination.5 See Haithcock, 958 F.2d at 678 (recognizing that a continuing violation exists where a policy of discrimination *409is longstanding and manifested in discriminatory treatment in more than one instance); see also Hull v. Cuyahoga Valley Joint Vocational Sch. District Bd. of Ed., 926 F.2d 505, 510-11 (6th Cir.1991) (stating that a complaint is timely filed and the continuing violation doctrine applies where a plaintiff challenges not just one incident of unlawful conduct but an unlawful practice that continues into the limitations period) (quotation omitted); see also United States v. International Assoc. of Bridge, Structural and Ornamental Iron Workers, Local No. 1, 438 F.2d 679, 683 (7th Cir.1971) (“[I]t is proper for a court to look at past discrimination to see whether an employer is perpetuating a pattern of discrimination through other means.... [T]he past sheds light on the present as well as the future. Past discrimination ... may be relevant to show motive and intent as to present practice or to establish a pattern or practice of discrimination or to show that present ... practices are designed to perpetuate or have the effect of perpetuating a past policy of discrimination.”).
Local 496 has a despicable and egregious history of excluding African Americans from membership. We will not ignore this legacy of discrimination, paradigmatic of a continuing violation. To do so would be inequitable and unjust. Therefore, because the defendants’ actions constitute a continuing violation, the district court correctly considered those actions which took place prior to the limitations period, as well as those that occurred within the limitations period. Accordingly, we affirm the judgment of the district court with regard to this issue.
b. Agency and Affirmative Duty Theories
LIUNA contends that the district court erred by finding it liable for the alleged racial discrimination of Local 496. The district court found that LIUNA was liable both because Local 496 was acting as the international union’s agent and because LIUNA breached its affirmative duty to oppose Local 496’s discriminatory practices by neglecting to remedy the alleged discrimination when it learned of the plaintiffs’ claims. Again, we review these findings of fact for clear error. See Berger v. Iron Workers Reinforced Rodmen Local 201, 843 F.2d 1395, 1407 (D.C.Cir.1988).
Common law agency theories of vicarious liability govern the liability of international labor organizations for the acts of their local unions that violate Title VII and § 1981. See id. at 1427-28. At common law, a principal may be held liable for the intentional torts of its agent if the agent’s conduct is within the scope of his agency and if, with the knowledge of the conditions, the principal intends the conduct or its consequences. See id. at 1430. In other words, in a case such as this, “a plaintiff must adduce specific evidence that the international ‘instigated, supported, ratified, or encouraged’ those actions,' or ‘that what was done was done by then-agents in accordance with their fundamental agreement of association.’ ” Id. at 1427 (quoting Carbon Fuel v. United Mine Workers, 444 U.S. 212, 217-18, 100 S.Ct. 410, 62 L.Ed.2d 394 (1979)). Furthermore, where an agency relationship exists, international unions are not only vicariously hable, they have an affirmative duty to oppose the local’s discriminatory conduct. See Sinyard v. Foote & Davies Div. of McCall Corp., 577 F.2d 943, 945 (5th Cir.1978).6 Thus, “[a]s a general proposition ... international labor unions must bear a heavy responsibility in giving effect to the remedial provisions of both Title VII” and § 1981. Id.
*410In this case, the district court correctly found that LIUNA is liable both vicariously and directly. LIUNA and Local 496 have clearly maintained a principal/agent relationship since March 1985 when LIU-NA became a signatory to the National Maintenance Agreement, which included a provision stating that Local 496 was to fill all maintenance laborer positions at Perry.7 However, the structure of the relationship between the local and the international was no different before this date, during Perry’s construction phase. The working-in-the-calling requirement, which we have determined had a disparate impact on African Americans, was in fact a product of LIUNA’s own Uniform Local Constitution. Article III, § 1(a) provides, “In order to be eligible for membership a person must be working in the calling within the territory of the Local Union in which the individual applies for membership.” We are baffled and amazed as to how LIUNA can contend that it did not instigate, support, ratify, or encourage a policy that it created. Moreover, LIUNA was aware and on notice of the charges of discrimination filed against Local 496, as Floyd Conrad and the EEOC both informed LIUNA personnel of such developments. Thus the international cannot feign ignorance, and cannot be excused for breaching its duty to end Local 496’s discrimination.8 See Berger, 843 F.2d at 1428 (“Having ... approved a practice of the local that was later found to be discriminatory in effect, the international would surely have been held accountable for the local’s conduct under the agency standard of the common law .... ”); see also Sagers v. Yellow Freight System, Inc., 529 F.2d 721, 736, n. 32 (5th Cir.1976) (stating that international unions who are parties to national agreements have a duty under Section 1981 to inquire into the effect of contract provisions when it is reasonable to assume that such provisions might lead to discrimi*411nation, and that international unions have an affirmative obligation to protect members from agreements they help negotiate when such agreements “lock in” past discrimination).
Here, the district court’s conclusion that LIUNA is hable is based on an eminently reasonable interpretation of the relationship between the international and local unions. Because the record and the applicable precedent support the district court’s conclusion that LIUNA is liable for Local 496’s discriminatory practices and policies, we affirm the judgment of the district court on this issue as well.
4. Date of Accrual of Title VII Damages
Defendants contend that even if we affirm the district court’s findings regarding liability, we should determine that the district court erred in determining the date upon which Title VII damages began to accrue against LIUNA. We review a district court’s designation of the beginning of a back pay period for an abuse of discretion. See Warren, 138 F.3d at 1094.
Section 706(g) of Title VII, as amended in 1972, provides that “[bjack pay liability shall not accrue from a date more than two years prior to the filing of a charge with the [Equal Employment Opportunity] Commission.” 42 U.S.C. § 2000e-5(g). Plaintiffs did not file an EEOC charge against LIUNA until September 7, 1989, and thus defendants argue that their Title VII liability did not accrue until September 7, 1987. However, the first plaintiff to file an EEOC charge against Local 496 did so on February 1, 1984. The district court, citing Romain v. Kurek, 836 F.2d 241 (6th Cir.1987), determined that back pay liability against LIUNA commenced more than two years before this earlier date, on February 1,1982.9
Romain outlines the conditions under which an unnamed party may be sued pursuant to the EEOC right-to-sue letter that results from an EEOC charge. “[A] party must be named in the EEOC charge before that party may be sued under Title VII unless there is a clear identity of interest between the unnamed party and a party named in the EEOC charge.” Id. at 245 (internal quotes omitted). In Romain, this court adopted two tests for determining whether a party shares an identity of interest with another party. Under the first, set forth by the Seventh Circuit in Eggleston v. Chicago Journeymen Plumbers’ Local Union No. 130, 657 F.2d 890 (7th Cir.1981), an identity of interest exists when the unnamed party possesses sufficient notice of the claim to participate in voluntary conciliation' proceedings. Romain, 836 F.2d at 245 (“Courts generally find an identity of interest where the unnamed party has been provided adequate notice of the charge under circumstances which afford him an opportunity to participate in conciliation proceedings aimed at voluntary compliance.”). The second, developed by the Third Circuit in Glus v. G.C. Murphy Co., 562 F.2d 880 (3rd Cir.1977), uses four factors to determine the relationship between the named and the unnamed parties at the time the charge was filed:
(1) [Wjhether the role of the unnamed party could through reasonable effort by the complainant be ascertained at the time of the filing of the EEOC complaint;
(2) [W]hether, under the circumstances, the interests of a named are so similar as the unnamed party’s that for the purpose of obtaining voluntary conciliation and compliance it would be unnecessary to include the unnamed party in the EEOC proceedings;
(3) [W]hether its absence from the EEOC proceedings resulted in actual *412prejudice to the interests of the unnamed party;
(4) [Wjhether the unnamed party has in some way represented to the complainant that its relationship with the complainant is to be through the named party.
Romain, 836 F.2d at 246. As might be expected, because we have found LIUNA vicariously liable for Local 496’s discriminatory practices and directly liable for violating its duty to stop those practices, under either test LIUNA and Local 496 share an identity of interest.
With regard to the Eggleston test, LIU-NA certainly had ample notice of the charges the plaintiffs filed against Local 496. Floyd Conrad notified regional LIU-NA officials who then informed national LIUNA personnel of all charges and relevant EEOC findings in this case. In addition, the EEOC and NLRB directly provided LIUNA with copies of all charges alleging discrimination by Local 496. LI-UNA enjoyed supervisory power to interfere in the affairs of Local 496 and chose not to exercise that power despite the ongoing charges of discrimination. In light of this fact, the district court’s finding that LIUNA had been provided with adequate notice affording it an opportunity to participate in, or at least encourage the other defendants to participate in, conciliation proceedings is not an abuse of discretion.
With regard to the- Glus multi-factor test, we add the following. First, the plaintiffs were unaware of LIUNA’s involvement in the affairs of Local 496 until well after the filing of the original EEOC charge; moreover, one could hardly expect those excluded from union membership to understand the relationship between international and local unions at the time they filed EEOC charges. Cf Romain, 836 F.2d at 245 (“The ‘identity of interest’ exception acknowledges the reality that laymen, unassisted by trained lawyers, initiate the process of filing a charge with the EEOC, and accordingly prevents frustration of the remedial goals of Title VII by not requiring procedural exactness in stating the charge.”). Second, the interests of LIUNA and the local were identical in terms of achieving voluntary conciliation with the plaintiffs during EEOC proceedings. Third, LIUNA was aware of the EEOC proceedings and thus was not prejudiced by the plaintiffs’ failure to name it in the original EEOC charge.10 Therefore, under the Glus test, as under the Eggle-ston test, we conclude that LIUNA and Local 496 shared an identity of interest.
Because of this identity of interest, LIU-NA could have been sued under the plaintiffs’ first EEOC charge. Accordingly, then, the plaintiffs’ second EEOC charge was not needed and we will not limit plaintiffs’ Title VII damages by the date of this second, unnecessary charge. The Second Circuit reached a similar conclusion in Cornwell v. Robinson, 23 F.3d 694 (2nd Cir.1994). Cornwell, like the plaintiffs in this case, was the victim of a pattern and practice of discrimination. Her original EEOC charge and her original complaint, both filed in 1986, named her employer and a few others. Both failed, however, to name the individual employees who had been harassing her. In June 1986, she filed a second EEOC charge naming those employees for incidents that took place the year after she filed her original charges. She eventually received a right-to-sue letter against those employees, but did not actually file a Title VII claim against them until 1992. After concluding that the incidents in 1986 were part of the same pattern and practice of discrimination that Cornwell had endured for several years, and thus were naturally “reasonably related” to the discrimination that she had complained of in her original EEOC charge, the Second Circuit concluded that Corn-well’s claim against the employees was not time barred, despite the fact that Title VII requires plaintiffs to sue within 90 days of the receipt of a right-to-sue letter. The court concluded:
*413we can see no basis in Title VII or in reason for concluding that the agency’s response to her unnecessary administrative claim imposed on her time constraints to which she would not have been subject had she not filed the unnecessary claim. A contrary, “technical” reading of a remedial statute such as Title VII would be particularly inappropriate in a statutory scheme in which laymen, unassisted by trained lawyers, initiate the process.
Id. at 706. We agree. Thus, we conclude that the district court did not abuse its discretion by determining that the parent union’s liability began to accrue at the same time as the local union’s liability on February 1, 1982, and we affirm the judgment of the district court with regard to this issue.
B. Plaintiffs’ Cross-Appeal
1. Date of Termination of Damages
The plaintiffs argue that the district court erred in establishing January 15, 1992 as the termination date of damages. The plaintiffs suggest that the district court should have adopted the magistrate judge’s recommendation that damages terminate on the date that final judgment in the case is entered. We review a district court’s order establishing the termination date of damages for an abuse of discretion. See Thornton v. East Texas Motor Freight, 497 F.2d 416, 422 (6th Cir.1974).
In this case, the district court declined to adopt the magistrate judge’s recommendation that the termination date for damages coincide with the final judgment date. The district court reasoned that:
The [order regarding liability] found [Local 496’s] referral policy adopted in October 1987 to be ‘facially objective and non-diseriminatory.’ With that finding, injunctive relief and job opportunities were available to the class following the liability decision. On January 15, 1992, attorneys for the class were in a position to request injunctive relief regarding future referrals. There is no good reason to allow damages beyond January 15, 1992.... The ending date for all damages is January 15,1992.
The district court’s conclusion was not based on an erroneous finding of fact or an incorrect application of the law. Thus, it was not an abuse of discretion. See Warren, 138 F.3d at 1095; see also Thornton, 497 F.2d at 416 (concluding that district court’s order establishing termination date of back pay relief in job discrimination ease on date the employer changed its discriminatory policy rather than the date when the court made the final award of damages was not an abuse of discretion). We accordingly affirm the judgment of the district court "with regard to this issue.11
2. Sanction of Plaintiffs’ Counsel
Plaintiffs contend that the district court erred by sanctioning their attorney for alleged misconduct pertaining to LIUNA’s discovery requests. We review a district court’s imposition of sanctions on attorneys for an abuse of discretion. See Palmer v. United States, 146 F.3d 361, 363 (6th Cir.1998) (citing Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 405, 110 S.Ct. 2447, 110 L.Ed.2d 359 (1990)). “A district court would necessarily abuse its discretion if it based its ruling on an erroneous view of the law or on a clearly erroneous assessment of the evidence.” Id.
As Magistrate Judge Hemann stated, the history of the discovery disputes that took place during the damages phase of this action “need not be repeated here. Suffice it to say that [Judge Hemann] spent considerable time dealing with defendants’ complaints about plaintiffs’ failures to provide in some cases any, and in most cases all, requested discovery.” With regard to these complaints, LIUNA *414filed a motion to dismiss forty-four members of the plaintiff class. In opposing LIUNA’s motion, all except six of the plaintiffs cured the complained-of deficiencies. Judge Hemann therefore recommended that the district court deny LIU-NA’s motion to dismiss, noting the huge number of interrogatories defendants propounded. Judge Hemann went on to suggest specific action with regard to the six stragglers. She also suggested that the district assess, against all forty-four plaintiffs who were the subject of LIUNA’s motion to dismiss, the attorneys’ fees LIU-NA incurred in filing the motion to dismiss. The district court adopted the report and recommendation, but ordered that plaintiffs’ counsel, rather than the plaintiffs themselves, pay the attorneys’ fees.
Nothing in the record leads us to believe that the district court misapplied the law or based its imposition of sanctions on a clearly erroneous assessment of the evidence. Therefore, we conclude that the district court did not abuse its discretion and affirm the imposition of sanctions on plaintiffs’ counsel.
III. CONCLUSION
For the foregoing reasons, with regard to the appeal, we AFFIRM the judgment of the district court in all respects. With regard to the cross-appeal, we also AFFIRM the judgment of the district court.
CONCURRING IN PART, DISSENTING IN PART
. Through its parent, LIUNA, Local 496 is a member of the AFL-CIO. Local 496’s jurisdiction is limited to building and construction work in Lake County, Ohio.
. Furthermore, between 1975 and 1979, Local 496’s membership increased by more than 500%. During the same time, black membership increased from approximately 12 members to 18 members. Between April 1982 and February 1984, 42 new members joined Local 496, none of whom was black.
. Additional white relatives of union members whom Conrad admitted to the union although they were not then "working in the calling” include: Donald Crofoot's son-in-law, David Yankee; Randy Isarelli's uncle, Thomas Isar-elli; David Russka; Robert Mackey; Thomas Schroeder; James Vechery, Jr.; Robert Loh-man; Donald Patton; Mickey Fisher; and two sons of Local 496's Field Representative, Rudy Bracale.
. Defendants contend that they did, in fact, waive the working-in-the-calling requirement for several African Americans. The record demonstrates that this is not the case. Two of those that the defendants claimed they waived the requirement for were already members of another union. The union constitution allows persons to freely transfer between unions. The remaining individuals had either obtained employment that was to begin once they were admitted to the union or had obtained letters indicating that they would be considered for employment once they were admitted to the union. The record indicates that the union considered such people working in the calling. The defendants point to no unemployed black non-member who was admitted to the union.
. Although exact dates are difficult to ascertain from the record, it appears that most of the class members approached Local 496 in the early and mid-1980s. Nevertheless, the record as a whole supports the conclusion that the defendants maintained racially discriminatory policies and practices well into the limitations period. In any event, the evidence certainly does not leave us with a definite and firm conviction that the district court committed a mistake in finding the defendants liable for a continuing violation. Therefore, we determine that the district court's finding was not clearly erroneous with regard to this issue. See Atlas Paper Box, 868 F.2d at 1493.
. The Fifth Circuit has held that an international union is liable for a local’s discrimination where a "sufficient connection” existed between the international and the local. See Myers v. Gilman Paper Corp., 544 F.2d 837, 851 (5th Cir.1977). The D.C. Circuit determined that the Myers "sufficient connection” test was not meaningfully different from common-law agency principles. See Berger, 843 F.2d at 1428. We agree.
. The dissent reaches a different conclusion, relying on General Bldg. Contractors Ass’n v. Pennsylvania, 458 U.S. 375, 102 S.Ct. 3141, 73 L.Ed.2d 835 (1982). Although that case did indeed involve a hiring hall and a claim of vicarious liability, it is distinguishable. The question there was whether an employer could be held liable for the discrimination of a union, obviously a very different question from the one at hand. "In the run of cases, the relationship between an employer and the union that represents its employees cannot be accurately characterized as one between principal and agent or master and servant. Indeed, such a conception is alien to the fundamental assumptions upon which the federal labor laws are structured.” Id. at 393. The theoretical underpinnings of the National Labor Relations Act do not compel a similar result here. To the contrary, it would be alien not to find an agency relationship when an international union signed a contract stating that the local — not the international— would provide workers for the employer.
. The dissent's, recognition that LIUNA attempted to explain its failure to investigate the plaintiffs’ charges of discrimination as "consistent with LIUNA's established practice upon receipt of similar complaints” begs the question whether the international’s "established practice” was sufficient under the circumstances. According to LIUNA’s answers to the plaintiffs’ interrogatories, it customarily referred charges of discrimination against locals to the relevant regional manager, in this instance Arconti. Arconti died in 1989, prior to the addition of LIUNA as a defendant. However, between 1984, when the plaintiffs filed their first EEOC charge against Local 496, and 1989, Arconti never investigated Local 496’s referral practices, much less sanctioned them. LIUNA conceded in its response to the interrogatories that it could not even verify whether Arconti ever met with representatives of Local 496 regarding the plaintiffs' charges. This leads us to wonder whether simply forwarding notice of charges of discrimination against a local union to the international's regional manager is an effective means of insuring the local’s compliance with civil rights law. Moreover, we note that in this case the regional manager notified the national office of LIUNA of the charges in the first place. We cannot comprehend how simply circulating between LIUNA's national and regional offices notice of the same EEOC charges and complaints without subsequent investigation could sufficiently address the local's alleged racial discrimination. We question what incentive LIUNA’s local unions have to comply with anti-discrimination statutes when they face no threat of sanction, or even investigation, by their parent union. Evidently, LIUNA’s "established practice” was not incentive enough.
. In other words, the district court determined that back pay liability under Title VII commenced on the same day for both LIUNA and Local 496.
. The fourth Glus factor is immaterial on these facts. LIUNA neither represented that plaintiffs’ relationship with it should or should not be through Local 496.
. Plaintiffs also challenge the accrual date of back pay against LIUNA under § 1981. Because of our conclusions with regard to the accrual of Title VII back pay against LIUNA, we decline to address this issue.