Full opinion text
HARLINGTON WOOD, Jr., Circuit Judge. These appeals are the outgrowth of protracted litigation stemming from an EEOC commissioner's charge filed against Sears, Roebuck & Company (Sears) on August 30, 1973. After efforts at settlement and conciliation failed, the EEOC brought suit against Sears on October 22, 1979, alleging several claims of nationwide discrimination against women (and minorities, but those claims were later withdrawn) in employment practices. Before trial the district court denied Sears' motion to dismiss, which was based on several grounds including an assertion that an EEOC attorney who headed the Sears investigation had a conflict of interest because he served on the Board of Directors of the National Organization for Women Legal Defense and Education Fund (LDEF) prior to and at the time NOW filed charges against Sears with the EEOC. EEOC v. Sears, Roebuck & Co., 504 F.Supp. 241 (N.D.Ill.1980) (Sears I). During the ten-month trial which began September 13, 1984, and consumed 135 trial days, the EEOC sought to prove that Sears engaged in a nationwide pattern or practice of discrimination against women from March 3, 1973 to December 31, 1980, by failing to hire and promote females into commission sales positions on the same basis as males and by paying female checklist management employees less than similarly situated male employees. The district court on January 31, 1986, held for Sears on all claims and also denied the EEOC's outstanding motion for partial summary judgment. EEOC v. Sears, Roebuck & Co., 628 F.Supp. 1264 (N.D.Ill.1986) (Sears II). The EEOC appeals the district court's judgment on the disparate treatment claims and its denial of partial summary judgment regarding a provision that had existed in the Sears Personnel Manual until 1974 allowing a male employee a day off with pay when his wife gave birth. Sears cross appeals the district court's refusal to dismiss the case on the alleged ground of conflict of interest. I. DISPARATE TREATMENT-LEGAL PRINCIPLES A. Standards of Review The EEOC does not challenge the district court's holding that this case involves claims of disparate treatment under Title VII § 703(a)(1), 42 U.S.C. § 2000e-2(a)(l). To succeed in a claim alleging disparate treatment, the EEOC ultimately had the burden of proving by a preponderance of the evidence that Sears engaged in a “pattern or practice” of discrimination against female employees. Bazemore v. Friday, 478 U.S. 385, 106 S.Ct. 3000, 3009, 92 L.Ed.2d 315 (1986) (per curiam) (Brennan, J., writing for majority, concurring in part). This includes proof of the employer’s discriminatory intent, a factor not required in the disparate impact analysis. International Brotherhood of Teamsters v. United States. 431 U.S. 324, 335 n. 14, 97 S.Ct. 1843, 1854 n. 14, 52 L.Ed.2d 396 (1977). Initially the EEOC, as plaintiff, had the burden of establishing a prima facie case that Sears followed an unlawful pattern or practice of discrimination. Id. “The plaintiffs’ prima facie case will thus usually consist of statistical evidence demonstrating substantial disparities in the application of employment actions as to minorities and the unprotected group, buttressed by evidence of general policies or specific instances of discrimination.” Coates v. Johnson & Johnson, 756 F.2d 524, 532 (7th Cir.1985) (footnote omitted). If a plaintiff meets that initial burden, the burden then shifts, temporarily, to the “employer to defeat the prima facie showing of a pattern or practice by demonstrating that the [plaintiffs’] proof is either inaccurate or insignificant.” Id. The burden shifts only temporarily because, as the Supreme Court explained in Bazemore, 106 5.Ct. at 3008, if the defendants ... have responded to the plaintiffs’ proof by offering evidence of their own, the factfinder then must decide whether the plaintiffs have demonstrated a pattern or practice of discrimination by a preponderance of the evidence. This is because the only issue to be decided at that point is whether the plaintiffs have actually proved discrimination. See also United States Postal Service Board of Governors v. Aikens, 460 U.S. 711, 715, 103 S.Ct. 1478, 1482, 75 L.Ed.2d 403 (1983). Whether the plaintiff has done so “will depend in a given case on the factual context of each case in light of all the evidence presented by both the plaintiff and the defendant.” Bazemore, 106 S.Ct. at 3009. In essence, therefore, the fact-finder looks at all the evidence, and does not accord any special significance to the fact that the plaintiff initially met its burden of proving a prima facie case. See Aikens, 460 U.S. at 715, 103 S.Ct. at 1482; Pollard v. Rea Magnet Wire Co., Inc., 824 F.2d 557, 558 (7th Cir.1987). The EEOC has not structured its argument to clearly fit within these principles, which gives the impression that it has a stronger case than it actually does. In presenting its hiring and promotion claims, the EEOC first argues that it has made out a prima facie case, and then contends that Sears failed to rebut that case. In addition, the EEOC makes statements such as “where plaintiffs present a sound statistical prima facie case, there is a substantial burden on the defendant to respond ... with a more probative analysis.” Although the district court did find that the EEOC had presented a prima facie case, whether the EEOC actually presented a sound statistical case is questionable. The district court did not find that it had, and we address that issue later. The EEOC implies through the structure of its presentation and statements such as the one quoted above that Sears had a heavy burden to rebut the EEOC’s evidence with more compelling evidence and even that Sears had the burden of persuasion. We find no support in the case law for those contentions. It is true that Sears had a rebuttal burden, but to meet that burden, Sears needed only to produce evidence that “raise[d] a genuine issue of fact as to whether it discriminated.” Texas Department of Community Affairs v. Burdine, 450 U.S. 248, 254, 101 S.Ct. 1089, 1094, 67 L.Ed.2d 207 (1981). Sears did not have a burden of producing more compelling evidence than did the EEOC. In Teamsters, the Supreme Court stated that an “employer’s defense must ... be designed to meet the prima facie case of the [plaintiff].” 431 U.S. at 360 n. 46, 97 S.Ct. at 1867 n. 46. We noted in Coates that “ ‘[t]he strength of the evidence the defendant must produce to prevent the plaintiff[s] from carrying the burden of persuasion ... depends, as in any case, on the strength of the plaintiffs’ proof.’" 756 F.2d at 532 (quoting Segar v. Smith, 738 F.2d 1249, 1268 (D.C.Cir.1984), cert. denied, 471 U.S. 1115, 105 S.Ct. 2357, 86 L.Ed.2d 258 (1985)). Whatever the nature of the defendant’s evidence, “the defendant need not carry the burden of persuasion as to the nonexistence of a disparity.” Segar, 738 F.2d at 1268. The EEOC could not necessarily rest on its showing of a prima facie case. As we noted above, once a defendant “respond[s] to the plaintiffs' proof by offering evidence of [its] own,” Bazemore, 106 S.Ct. at 3008, the fact that the plaintiff proved a prima facie case is of no continuing consequence. “The ultimate burden of persuading the trier of fact that the defendant intentionally discriminated against the plaintiff remains at all times with the plaintiff.” Burdine, 450 U.S. at 253,101 S.Ct. at 1093; see Bazemore, 106 S.Ct. at 3008. The district court’s determination as to whether the plaintiff has proved discrimination by a preponderance of the evidence “is subject to the clearly erroneous standard on appellate review.” Bazemore, 106 S.Ct. at 3008. The district court’s factual findings underlying that ultimate determination are also subject to the clearly erroneous standard. Under that standard, “ ‘[a] finding is “clearly erroneous” when although there is evidence to support it, the reviewing court on the entire evidence is left with the definite and firm conviction that a mistake has been committed.’ ” Anderson v. City of Bessemer City, 470 U.S. 564, 573, 105 S.Ct. 1504, 1511, 84 L.Ed.2d 518 (1985) (quoting United States v. United States Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 542, 92 L.Ed. 746 (1948)). We may have such a conviction if “the trial judge’s interpretation of the facts is implausible, illogical, internally inconsistent or contradicted by documentary or other extrinsic evidence.” Ratliff v. City of Milwaukee, 795 F.2d 612, 617 (7th Cir.1986). “If the district court’s account of the evidence is plausible in light of the record viewed in its entirety, the court of appeals may not reverse it even though convinced that had it been sitting as the trier of fact, it would have weighed the evidence differently.” Anderson, 470 U.S. at 573-74, 105 S.Ct. at 1511. In addition “[w]here there are two permissible views of the evidence, the factfinder’s choice between them cannot be clearly erroneous.” Id.; see Boxhom’s Big Muskego Gun Club, Inc. v. Electrical Workers Local 494, 798 F.2d 1016, 1018 (7th Cir.1986). The district court in this case made a multitude of factual findings. Some of those findings rested on determinations of the credibility of various witnesses, and some were based on the district court’s evaluation of statistical evidence. We accord even more deference to the district court’s findings based on evaluations of those types of evidence. In Anderson, 470 U.S. at 575, 105 S.Ct. at 1512, the Supreme Court noted that “[w]hen findings are based on determinations regarding the credibility of witnesses, Rule 52(a) demands even greater deference to the trial court’s findings; for only the trial judge can be aware of the variations in demeanor and tone of voice that bear so heavily on the listener’s understanding of and belief in what is said.” A finding that is “purportedly based on a credibility determination” may be clearly erroneous, however, if doc-ments or objective evidence “contradict the witness’ story; or the story itself may be so internally inconsistent or implausible on its face that a reasonable factfinder would not credit it.” Id. at 575, 105 S.Ct. at 1512; see Wheeler v. Snyder Buick, Inc., 794 F.2d 1228, 1232 (7th Cir.1986). We must also defer to the district court to a certain extent regarding the court’s factual findings based on statistical evidence. As the district court noted, “[virtually all the proof offered by the EEOC in this case is statistical in nature, or related to the statistical evidence.” Sears II, 628 F.Supp. at 1285. We stated in Soria v. Ozinga Brothers, Inc., 704 F.2d 990, 995 n. 6 (7th Cir.1983), that “[ejspecially where statistical evidence is involved, great deference is due the district court’s determination of whether the resultant numbers are sufficiently probative of the ultimate fact in issue.” In Soria, which involved, as did this case “a Babel of competing experts, contradictory statistical demonstrations, and diametrically opposed accounts of crucial events,” the court found it necessary to “wholly defer to the district court’s assessment of the credibility of both lay and expert witnesses and [had to] only disturb its resolution of dissonant evidence if that resolution is manifestly erroneous.” Id. We follow suit in this case, as the district court had to resolve the “contradictory statistical demonstrations” proffered by the primary statistical experts for each side — Dr. Bernard R. Siskin for the EEOC and Dr. Joan G. Haworth for Sears. These two witnesses together produced 5,275 pages of trial testimony. The judge specifically stated regarding this testimony that “[t]he credibility of statistical experts and the weight to be given their testimony were ... of great importance.” Sears II, 628 F.Supp. at 1279 & n. 2. B. Absence of Individual Victim Testimony Regarding all major claims at issue —hiring, promotion and compensation — the district court found that EEOC’s failure to present testimony of any witnesses who claimed that they had been victims of discrimination by Sears confirmed the weaknesses of the EEOC’s statistical evidence. The EEOC, conceding it did not present any witnesses who testified to individual acts of discrimination, argues that the district court gave undue weight to the absence of individual victim testimony. The EEOC cites Bazemore v. Friday, 478 U.S. 385, 106 S.Ct. 3000, 92 L.Ed.2d 315 (1986), International Brotherhood of Teamsters v. United States, 431 U.S. 324, 97 S.Ct. 1843, 52 L.Ed.2d 396 (1977), and Hazelwood School District v. United States, 433 U.S. 299, 97 S.Ct. 2736, 53 L.Ed.2d 768 (1977), for the proposition that individual victim testimony is unnecessary. We agree that those cases did not hold that individual victim testimony is necessary to support a finding of intentional discrimination in violation of Title VII. See Hazelwood, 433 U.S. at 307-08, 97 S.Ct. at 2741; Teamsters, 431 U.S. at 339, 97 S.Ct. at 1856. Neither did the district court in this case. We believe the district court accorded this lack of evidence the proper weight. We acknowledge that in Hazelwood School District, 433 U.S. at 307-08, 97 S.Ct. at 2741, the Supreme Court held that “[w]here gross statistical disparities can be shown, they alone may in a proper case constitute prima facie proof of a pattern or practice of discrimination.” The Court had earlier recognized in Teamsters, 431 U.S. at 339, 97 S.Ct. at 1856, however, that individual victim testimony is useful to bring “cold numbers convincingly to life.” This court has recognized that “examples of individual discrimination are not always required, but we think that the lack of such proof reinforces the doubt arising from the questions about validity of the statistical evidence.” Griffin v. Board of Regents, 795 F.2d 1281, 1292 (7th Cir.1986). Similarly, in Garcia v. Rush-Presbyterian-St. Luke’s Medical Center, 660 F.2d 1217, 1225 (7th Cir.1981), we stated: We find very damaging to plaintiffs’ position the fact that not only was their statistical evidence insufficient, but that they failed completely to come forward with any direct or anecdotal evidence of discriminatory employment practices by defendants. Plaintiffs did not present in evidence even one specific instance of discrimination. There was no individual to testify how defendant discriminated against him. See also Rossini v. Ogilvy & Mather, Inc., 798 F.2d 590, 604 (2d Cir.1986) (“In evaluating all of the evidence in a discrimination case, a district court may properly consider the quality of any anecdotal evidence or the absence of such evidence.” (citing EEOC, 628 F.Supp. at 1278 n. 2)). The district court properly recognized the value of anecdotal evidence when it determined that lack of individual victim testimony reinforced its conclusions regarding the deficiencies in the EEOC’s statistical evidence. Segar v. Smith, 738 F.2d 1249, 1278 (D.C.Cir.1984), cert. denied, 471 U.S. 1115, 105 S.Ct. 2357, 86 L.Ed.2d 258 (1985), is not to the contrary. In Segar, the District of Columbia Circuit stated that “when a plaintiff’s statistical methodology focuses on the appropriate labor pool and generates evidence of discrimination at a statistically significant level, no sound policy reason exists for subjecting the plaintiff to the additional requirement of either providing anecdotal evidence or showing gross disparities.” Id. at 1278. In this case the district court considered the lack of anecdotal evidence only after finding there were major problems with the EEOC’s labor pool and determining that the EEOC’s statistical evidence was severely flawed. This is in accord with the District of Columbia Circuit’s statement in Valentino v. United States Postal Service, 674 F.2d 56, 69 (D.C.Cir.1982), that “when the statistical evidence does not adequately account for ‘the diverse and specialized qualifications necessary for [the positions in question],’ strong evidence of individual instances of discrimination becomes vital to the plaintiff’s case.” (bracketed material in original) (quoting Wilkins v. University of Houston, 654 F.2d 388, 410 (5th Cir. Unit A Dec. 1981), vacated, 459 U.S. 809, 103 S.Ct. 34, 74 L.Ed.2d 47 (1982)). When experts disagree, as they did here, the court may need the help of live witnesses to relate their actual experiences. The EEOC’s reasons for not presenting such individual testimony are not satisfying. The EEOC argues that such evidence would be “inappropriate” because “where 47,000 hires and promotions were at issue ... it would have been impossible to present enough individual demonstrations [sic] of discrimination to meaningfully reflect on the statistics.” We do not agree that examples of individual instances of discrimination must be numerous to be meaningful. Even a few examples would have helped bring “cold numbers convine-ingly to life.” Teamsters, 431 U.S. at 339, 97 S.Ct. at 1856. Furthermore, we agree with the district judge that considering the ten-year length of the lawsuit and the amount of investigation by the EEOC and information passed by Sears to the EEOC, it is difficult to see how the EEOC could fail to “identify at least some members of the alleged huge class of victims it purports to represent.” Sears II, 628 F.Supp. at 1325 & n. 82. The EEOC also argues that an individual applicant would not know if she had been discriminated against. While this speculative argument may be more apt for the hiring situation, in which an applicant may not know whether there was a vacancy or the qualifications of other persons who were hired, we agree with the district judge that in the area of promotions and compensation at least, the number of Title YII suits filed by individuals against employers in general “seems to fairly refute EEOC’s contention.” Id. II. DISPARATE TREATMENT-HIRING AND PROMOTIONS The EEOC argues that the district court erred in determining that it did not show a pattern or practice of discrimination by Sears against women in hiring and promotions into commission sales positions. We base our decision on the well-reasoned and comprehensive opinion .of the district court, see Sears II, 628 F.Supp. at 1277, and address the principal and dispositive issues raised by the parties. Although in Coates v. Johnson & Johnson, 756 F.2d 524, 533 (7th Cir.1985), this court briefly reviewed all the evidence in that disparate treatment case, it is not expedient or necessary to do so here, considering the variety and amount of statistical and nonstatistical evidence and the detailed summary of all the evidence by the district court in its opinion on the merits. Although we consider all the evidence, we will review the evidence here only to the extent necessary to consider the EEOC’s contentions that the district court has clearly erred in reaching various factual findings. The nature of the evidence presented by each party in this case was significantly different. It is helpful to briefly overview the types of evidence presented by the parties. The EEOC presented, almost exclusively, statistical evidence in the form of regression analyses based on information from employment applications of rejected sales applicants and Sears’ computerized payroll records from 1973 through 1980. The EEOC based other regression analyses on information from Applicant Interview Guides Sears had administered at various times from 1978 through 1980 at two Sears stores in its Southwestern Territory. The EEOC attempted to bolster this statistical evidence through nonstatistical evidence regarding the subjective nature of Sears’ selection process and allegedly discriminatory aspects of Sears’ testing practices. Sears did not respond with like regression analyses based on employment application and payroll records. Instead, most of Sears’ evidence was directed at undermining two assumptions Sears claimed were faulty and fatal to the validity of the EEOC’s statistical analysis — the assumptions of equal interests and qualifications of applicants for commission sales positions. This evidence consisted of testimony by Sears store managers, personnel managers, and other store officials, a study based on interviews of women in nontraditional jobs at Sears, national surveys and polls regarding the changing status of women in American society, morale surveys of Sears employees and 1976 and 1982 job interest surveys of Sears employees, national labor force data, and an analysis of the Applicant Interview Guides that attempts to measure differences in interest among men and women. Sears also presented evidence regarding its hiring figures, general evidence regarding the characteristics of commission salespersons including a case study of all commission sales hires in all stores, based on information in personnel files of applicants who were hired and sales performance data, evidence regarding the employment milieu at Sears, especially relating to commission selling and the structure of Sears, and evidence regarding its affirmative action efforts. Regarding the claim of discrimination in promotions, the EEOC again relied almost totally on regression analyses based on female proportions of noncommission salespersons in each store at the end of a year compared with the proportion of women actually hired into commission sales. Sears again relied on the evidence relating to interest, the nature of commission sales, characteristics of commission salespeople, and its affirmative action efforts. In addition, Sears introduced further evidence of interest in the form of responses to Career Aspirations Questionnaires it had administered to noncommission salespersons, and performed various adjustments of the EEOC’s statistical analysis. Each side featured one primary expert on statistical evidence — the EEOC starred Dr. Bernard R. Siskin in this role, while Sears was represented by Dr. Joan G. Ha-worth. The EEOC argues that Sears’ “generalized interest evidence” is inadequate as a matter of law to refute the EEOC’s statistical presentation. We have already partially discussed this argument in the context of the burdens of proof, but there is another aspect of this argument. The EEOC implies that Sears had the burden of responding with a more probative statistical analysis. The Supreme Court in Teamsters specifically stated, however, that “[w]e do not ... suggest that there are any particular limits on the type of evidence an employer may use.” 431 U.S. at 360 n. 46, 97 S.Ct. at 1867 n. 46. An employer may attempt to show that plaintiffs’ proof is “either inaccurate or insignificant,” id. at 360, 97 S.Ct. at 1867, or the plaintiff may attempt to provide a “nondiscriminatory explanation for the apparently discriminatory result.” Id. at 361 n. 46, 97 S.Ct. at 1867 n. 46. Then-Justice, now Chief Justice Rehnquist, concurring in Dothard v. Rawlinson, 433 U.S. 321, 338-39, 97 S.Ct. 2720, 2731, 53 L.Ed.2d 786 (1977), stated that defendants in a discrimination case “may endeav- or [in rebuttal] to impeach the reliability of the statistical evidence, they may offer rebutting evidence, or they may disparage in arguments or in briefs the probative weight which the plaintiffs’ evidence should be accorded.” See also Catlett v. Missouri Highway & Transportation Commission, 828 F.2d 1260, 1266 (8th Cir.1987) (defendant may introduce evidence that a lesser interest in certain jobs on part of female applicants explains statistical disparity); Segar v. Smith, 738 F.2d 1249, 1268 (D.C.Cir.1984) (defense “[t]ypically ... will focus on the integrity of the plaintiffs’ statistical methodology and the significance of the results shown”), cert. denied, 471 U.S. 1115, 105 S.Ct. 2357, 86 L.Ed.2d 258 (1985). “The defendants’ rebuttal must ... at least raise a genuine issue of material fact concerning the accuracy of the picture painted by the plaintiffs’ statistics.” Segar, 738 F.2d at 1268. The cases cited by the EEOC to support its argument that Sears had the burden of rebutting its statistical analysis with more “refined, accurate and valid” statistical evidence did not state that the defendant must produce such evidence to succeed in rebutting the plaintiffs’ case. Instead, those cases indicated that a defendant could or “was entitled to” use such a means of rebuttal. See Shidaker v. Carlin, 782 F.2d 746, 750 (7th Cir.1986), vacated, — U.S. —, 107 S.Ct. 1621, 95 L.Ed.2d 195 (1987); Movement for Opportunity & Equality v. General Motors Corp., 622 F.2d 1235, 1245 (7th Cir.1980). These cases involve disparate impact claims — without deciding whether these principles are applicable in a disparate treatment case, we can say that EEOC misconstrues the principles. These cases suggest, and the cases we have cited above confirm, that statistical evidence is only one method of rebutting a statistical case. Cf. Teamsters, 431 U.S. at 340, 97 S.Ct. at 1827 (“Statistics are not irrefutable; they come in infinite variety and, like any other kind of evidence, they may be rebutted. In short, their usefulness depends on all of the surrounding facts and circumstances.”). We therefore reject the EEOC’s contention that Sears’ interest evidence, consisting of testimony of Sears’ store witnesses, external labor force data, national survey data, and data from surveys of Sears’ employees, is insufficient as a matter of law to undermine the EEOC’s statistical evidence. Before we discuss the specifics of the EEOC’s challenges to the district court’s findings regarding the EEOC’s hiring and promotion claims, we address the EEOC’s arguments that the district court erred as a matter of law in analyzing those claims. The EEOC contends that the district court erred as a matter of law by failing to address separately a period of liability the EEOC terms “the early years.” Second, the EEOC argues that the court erred by not considering its claims of discrimination regarding part-time hires separately from its claims of discrimination regarding full-time hires. A. Early Years The EEOC argues that the district court erred as a matter of law by failing to address separately what the EEOC terms “the earlier years” at issue in its hiring and promotion into commission sales claims. In support of this argument, the EEOC cites various cases it says stand for the proposition that “[t]he law clearly requires that a defendant’s employment practices prior to its taking corrective action be examined separately.” We do not read the cases as supporting that particular proposition. Instead, we believe the cases hold, at most, that an employer’s corrective action does not absolve the employer from liability based on discriminatory practices occurring before the employer took the corrective action. See Teamsters, 431 U.S. at 341-42, 97 S.Ct. at 1857-58; Rich v. Martin Marietta Corp., 522 F.2d 333, 346 (10th Cir.1975); Parham v. Southwestern Bell Telephone Co., 433 F.2d 421, 425-26 (8th Cir.1970); Patterson v. Youngstown Sheet & Tube Co., 440 F.Supp. 409, 412-13 (N.D.Ind.1977) (defendant employer not permitted to combine statistics for precharge and post-charge periods, because “[ajctions taken subsequent to the filing of E.E.O.C. charges cannot moot issues of discrimination occurring prior to that time”), aff'd, 659 F.2d 736 (7th Cir.), cert. denied, 454 U.S. 1100, 102 S.Ct. 674, 70 L.Ed.2d 641 (1981); cf. Capad v. Katz & Besthoff, Inc., 711 F.2d 647, 655-57 (5th Cir.1983), cert. denied, 466 U.S. 927, 104 S.Ct. 1709, 80 L.Ed.2d 182 (1984). These cases are all characterized by an assumption that employer practices in existence before some form of “corrective action” (usually occurring after Title VII charges were filed against the employer) were in fact discriminatory. The district court in this case, however, never found that Sears engaged in discriminatory hiring and promotion practices before the EEOC filed charges or before Sears began affirmative action efforts. The district court also never held that Sears’ later policies and programs absolved Sears of any liability for earlier discriminatory practices. Instead, the district court found that the EEOC’s statistics failed to prove liability for any period at issue in this case and that Sears’ affirmative action efforts began as early as 1968, well before the EEOC’s August 1973 charge. The EEOC’s challenge is thus not that the district court erred as a matter of law. Its argument is more properly characterized as a claim that the court incorrectly failed to make two factual findings, either finding of which should have led the district court to consider the “early years” separately from the later period. One of those findings the EEOC claims the district court erred in not making was that there were significant differences between the “early years” and the later years in the liability period of 1973 to 1980. The second finding would have been that Sears adopted the Mandatory Achievement of Goals (MAG) affirmative action plan in response to the EEOC’s charge, or that Sears designed the MAG program as a corrective action to “bless” earlier discriminatory practices. On review of factual findings, we will uphold the district court’s findings unless they are clearly erroneous. See Anderson v. City of Bessemer City, 470 U.S. 564, 573, 105 S.Ct. 1504, 1511, 84 L.Ed.2d 518 (1985); Andre v. Bendix Corp., 774 F.2d 786, 788 (7th Cir.1985). We are not persuaded that the district court’s failure to make either of the above findings was clear error. The EEOC claims that during the “early years” “there were fundamental changes in Sears’ practices regarding the hiring and promotion of women into commission sales positions.” The EEOC then cites statistics indicating that in various sales departments (e.g., auto accessories or furniture), percentages of commission saleswomen doubled, tripled, quadrupled, or increased up to eightfold during various “early” periods. Initially, we note that the district court found that all of the EEOC statistics were plagued by arbitrary and false assumptions. We discuss these statistical defects in more detail later. Because we find that the district court did not err in its criticisms of the EEOC’s statistics, we cannot accept the EEOC’s argument that those statistics indicated differences that the district court should have recognized by separating “early years” from later years. Even if the district court had found the EEOC’s underlying statistics sound, we are not convinced by the EEOC’s arguments that the district court should have recognized differences between “early years” and some later period. First, we are unsure what the EEOC means by the term “early years,” because the EEOC never specifically defined that term. The district court designated the liability period as beginning March 3, 1973 and ending in 1980. At various points in its argument, the EEOC suggests that the “early years” is a period from 1972 (the year before the EEOC charge was filed) to 1975 (two years after the charge was filed), the period before August 30,1973 (when the EEOC filed charges), a period from 1973 to 1975, or the period before the summer of 1974 (when Sears implemented the MAG program). Because the EEOC ultimately wants to argue that it can show that Sears discriminated before the implementation of its affirmative action program by separating the figures before and after implementation of affirmative action, we believe the EEOC means the “early years” as the beginning of the liability period, which the district court found was March 30, 1973, to the implementation of the MAG program in the summer of 1974. Assuming that this fifteen- to sixteen-month period constitutes the “early years,” we are not convinced by the EEOC’s arguments and statistics that the district court erred by failing to recognize significant differences between this period and the years following it. The EEOC did not emphasize this period in its complaint, nor did it present data corresponding to this fifteen- to sixteen-month period that it now claims should have been considered separately. Neither did it attempt to distinguish data for promotions and hires during this period from data for promotions and hires during the time beginning after the “early years” ended. Instead, the statistics it cites to us on appeal (which were also presented to the district court) as indicating “dramatic changes” in hiring and promotion encompass periods before and after the “early years.” The EEOC presented data on promotions and hires broken down by year, beginning with 1972. Its figures for 1973 thus included two months of hires and promotions before the relevant liability period began, and its data for 1974 included five to six months of hires and promotions that occurred after the MAG plan was implemented. The data compiled and presented to this court by the EEOC are misleading as well as imprecise. The EEOC, in citing statistics it says show “dramatic increases” during the “early years,” does not carefully recognize or refer to that time period. For example, it states that between 1972, the year before the EEOC charge was filed, and 1975, two years after the charge was filed, the female proportion of full-time commission sales hires more than tripled (from 9.97® to 31.1%) and in breaking down the figures by division, that in Sewing Machines, during this three-year period, the female proportion of full-time hires almost tripled (from 13.5% to 47.9%) and in Furniture, it more than quadrupled between 1972 and 1974 alone (8.1% to 33.8%) and had increased more than fivefold (to 43.0%) by 1976. These statistics obfuscate increases that took place during the “early years,” before the implementation of the MAG plan. Although the EEOC claimed that the female percentage of sales hires “more than tripled” between 1972 and 1975, the same percentage nearly doubled between 1972 and 1973. Analysis by division of products is similarly misleading— percentages of Sewing Machines hires that the EEOC says “almost tripled” between 1972 and 1975 more than doubled between 1972 and 1973 and percentages for the Furniture division that “more than quadrupled” between 1972 and 1974 tripled between 1972 and 1973. Some of the statistics the EEOC cites are for a time period that approximates the “early years,” but fail to support its argument that there were differences before and after implementation of the MAG plan. The EEOC claimed that between 1973 and 1974 alone, which would be during the “early years” period, the female percentage of hires more than tripled in Hardware and increased almost twenty times in Plumbing and Heating (the latter figure almost trebling by the next year). Other EEOC compilations of statistics are misleading for different reasons. The EEOC claims that the female percentage of commission sales hires for part-time outside the Midwestern Territory more than doubled between 1972 and 1975. A close look at the data indicates that the percentage was increasing steadily from 1972 to 1974, including during 1973-1974, which is fairly close to the “early years” period at issue. While some of the data seems to support the “differences” claimed by the EEOC— for example, the female percentage in Auto Accessories increased more than eightfold between 1972 and 1974 and more than twelvefold between 1972 and 1975 — the difference in percentage increases between 1972-1974 and 1974-1975 is not as great as the EEOC’s compilation of data suggests. In short, the EEOC’s attempts to show significant differences between pre-MAG and post-MAG percentages of female workers are insufficient to persuade us that the district court clearly erred in failing to recognize the alleged increases by considering the “early years” separately. The second aspect of the EEOC’s claim that the district court should have separately considered the “early years” is that the district court clearly erred in failing to find that Sears’ implementation of the MAG plan was corrective action taken by Sears in response to the EEOC’s charges to escape liability for its earlier discrimination. The district court found, however, that Sears’ commitment to affirmative action began in 1968, Sears in 1969 set a long-term goal of 38% women at all jobs at Sears, and in April 1970, “Sears instituted a centralized, company-wide affirmative action program for women and minorities,” which was revised in 1972. Sears II, 628 F.Supp. at 1293. The EEOC argues that nothing in the record supports the district court’s findings that “attracting women to commission sales at Sears has been an important priority in Sears’ affirmative action program since the first affirmative action questionnaire was circulated in 1968” and that Sears had engaged in pre-MAG efforts to hire or promote women into commission sales. Yet the EEOC acknowledges that in 1972 Sears’ affirmative action plan mentioned the movement of women into commission sales positions. The year 1972 is pre-MAG, because, as the court found, MAG was implemented in mid-1974. The EEOC also fails to refute the district court’s finding that Sears set a long-term goal of 38% women at all jobs at Sears in 1969 — presumably “all jobs” includes commission sales jobs. The EEOC attempts to characterize the MAG plan as a response to its charge against Sears by quoting the remarks of Sears Chairman Arthur M. Wood at a meeting of top executives to discuss affirmative action. Wood stated: The fact is that Sears has been identified as a target by the [Equal Employment Opportunity] Commission and we must improve our situation quickly in order to be in as defensible position as possible — to do this I want to urge our lawyers and others working on discrimination cases to conciliate every possible claim; in short, we should stay out of court and out of direct confrontation with enforcement agencies as long as possible, giving our program of voluntary action time to show meaningful progress for minorities and women. This remark, however, is not proof that Sears implemented MAG in response to the EEOC's charge. The remark was made May 21, 1973, more than three months before the charge was filed. On its face the remark indicates nothing more than that Sears was aware of potential EEOC action, although the EEOC claims that Wood had been informed by Ray J. Graham, Sears' Director of Equal Opportunity from 1968 through 1980, of the likelihood of the EEOC's bringing a National Programs charge against Sears. Other evidence is consistent with the court's finding that Sears' affirmative action efforts began in 1968. Graham testified, "I can't emphasize too strongly that it was not the threat of EEOC action that caused Sears to [adopt the MAG plan]," and stated that at the time of the meeting he had no knowledge of any EEOC "targeting" of Sears. Graham further testified that the MAG program was designed to "accelerate [Sears'] progress" and continue Sears' "leadership" role in affirmative action, and that Sears had "one [affirmative action] plan from the very outset [in 1968]." Furthermore, the EEOC never identified at trial the policies or practices of the MAG plan that allegedly changed the disparities generated by its statistical analyses. Apart from saying that MAG was "materially different" from earlier affirmative action programs, the EEOC does not state what the changed practices were. The EEOC has not per-, suaded us that the district court clearly erred in finding that Sears' affirmative action commitment began in 1968. We hold that the court did not err in not considering the "early years" separately. B. Part-Time The EEOC also argues that the district court erred as a matter of law in failing to consider the EEOC's claims of discrimination regarding part-time hires separately from its claims regarding full-time hires. The EEOC cites no authority for this proposition, but argues that separate consideration of part-time from full-time is compelled by "significant differences between part time and full time hires." This is not a question of law; rather, the EEOC must be arguing that the district court clearly erred in failing to find the alleged fact that differences between part-time and full-time hires were significant enough to warrant separate discussion of the part-time figures. One difference, according to the EEOC, is that the mix of products sold was different between full- and part-time, which the EEOC claims is significant because "the court based much of its opinion on the nature of the products sold." The other difference mentioned by the EEOC is that Siskin's multicell analysis produced larger disparities for part-time hires than for full-time hires. The district court did not, as the EEOC appears to suggest, ignore or never consider part-time figures. Neither did it completely subsume the part-time within the full-time case. At various points in its opinion the court referred to part-time data and disparities as distinct from full-time data and disparities. It appears that the court did refer to the full-time case more than it did the part-time case, but that may be explained by the fact that the full-time case was emphasized more at trial. Indeed, the court explicitly stated that "[f]ull time and part time positions ... were analyzed separately [by the parties]. The court will structure its analysis accordingly.” Sears II, 628 F.Supp. at 1288. Although the EEOC analyzed part-time figures separately from full-time figures, it employed the same mode of analysis to part-time and full-time data. Thus the part-time statistics were subject to the same criticisms by the district court as were the full-time statistics. We address these flaws recognized by the district court in more detail later. At this point it is sufficient to note that the part-time analy-ses, like the full-time analyses, are fraught with design flaws as well as a failure to capture differences in male and female interests and qualifications. In addition, Sears’ defense of affirmative action applied to both full- and part-time analyses. To the extent that the part-time figures as well as the full-time figures are misleading and imprecise, the EEOC’s claim that differences between part-time and full-time disparities were significant enough to warrant separate consideration of the part-time disparities is without merit. The EEOC also argues that the district court impermissibly failed to recognize a distinction between part-time and full-time hires based on differences in product lines. The EEOC criticizes two of the district court’s statements that give the impression, according to the EEOC, that the district court believed commission selling involved solely “big ticket” items such as major appliances. Such an impression would lead to false conclusions according to the EEOC, because commission selling involved smaller items like shoes as well as big ticket items like furnaces, and “big ticket” product lines were a small part of part-time hires compared with smaller product lines like shoes. We are unconvinced that the district court clearly erred in failing to recognize a distinction between part-time and full-time figures based on certain product lines in commission sales. First, we do not believe as the EEOC claims, “the court based much of its opinion on the nature of the products sold.” The two statements cited by the EEOC in support of its claim are “Commission selling usually involved ‘big ticket’ items, meaning high-cost merchandise, such as major appliances, furnaces, air conditioners, roofing, tires, sewing machines, etc.,” Sears II, 628 F.Supp. at 1289, and “the product lines into which 95 percent of Sears’ full time commission salespersons were hired included such items as hardware, building supplies, paint and appliances.” Id. at 1313 n. 58. These statements do not exclude product lines in which the EEOC claims there was a more persuasive part-time case. Second, these statements are insufficient to convince us that the nature of the products sold was crucial to the district court’s reasoning. These are two statements in a seventy-six-page published opinion. We do not believe that the district court failed to address the •EEOC’s claims of discrimination against part-time employees. C. Hiring The district judge found a plethora of problems in the statistical analyses that the EEOC had offered to support the claim that Sears discriminated against women in hiring into commission sales positions from 1973 to 1980. Before addressing the EEOC’s specific challenges to the district court’s criticisms of its statistical evidence, it is helpful to discuss three key findings made by the district court, which we believe are not clearly erroneous. Those findings are that during the period at issue in this case (1973-1980): (1) commission selling was significantly different from noncommission selling at Sears; (2) women were not as interested in commission selling as were men; and (3) women were not as qualified for commission selling as were men. The finding that colors the district court’s entire treatment of the EEOC’s hiring as well as its promotion claims is that selling on commission at Sears is a very different job from “regular,” or noncom-mission selling at Sears. We cannot say that finding is clearly erroneous. The court’s description of commission and non-commission selling at Sears indicates that the two forms of selling differed in the type of merchandise sold, the risk involved, which was reflected in the manner of compensation, and the technical, knowledge, expertise, and motivation involved. The district court describes the differences at length, see Sears II, 628 F.Supp. at 1289-90, thus we need only mention major differences. As the district court found, commission selling at Sears usually involved selling “big ticket” items, which are high-cost merchandise such as major appliances, furnaces, roofing, and sewing machines. Merchandise sold on a noncommission basis understandably was generally low-cost and included apparel, paint, and cosmetics. Commission selling involved some risk, especially before 1977. During that period commission salespersons generally received a commission ranging from 6% to 9% percent plus a “draw” each week. The draw usually did not exceed 70% of average or estimated earnings, but was subject to reduction if the employee’s commission did not equal the amount of the draw. There was always a risk that the employee could lose some of the draw if the commissions did not equal the amount of the draw. After 1977, commission salespersons no longer faced deficits. In what the court noted was an effort “to reduce the financial risk of selling on commission in an effort to attract more women to commission sales,” Sears paid commission salespersons a nominal salary plus a 3% commission. Id. at 1289. Noncommission salespersons were paid on a straight hourly rate, and full-time salespersons received 1% commission on all sales until January 1979 when the practice was discontinued. The district court found that commission selling often required salespersons to be available after the normal working hours of 8:00 a.m. to 5:00 p.m., sometimes required that they sell in people’s homes, might require a license depending on the products sold, and required qualities usually not as necessary in regular selling, including a high degree of technical knowledge, expertise, and motivation. The court’s next two major findings, that there were different interests and qualifications among men and women for commission selling, were grounded in part on the court’s recognition of differences between noncommission and commission selling at Sears. The court based these findings on the large amount of evidence presented by Sears on these issues. The court extensively discusses this evidence. Id. at 1305-15. Again, we cannot say that these findings are clearly erroneous. Regarding the question of differing interests in general among men and women in commission selling, we have already briefly reviewed the types of evidence presented by Sears to the district court on this issue. We need only highlight some significant findings of the court in support of our determination that the court’s finding was not clearly erroneous. The court found that “[t]he most credible and convincing evidence offered at trial regarding women’s interest in commission sales at Sears was the detailed, uncontradicted testimony of numerous men and women who were Sears store managers, personnel managers and other officials, regarding their efforts to recruit women into commission sales.” Id. at 1306. These witnesses testified to their only limited success in affirmative action efforts to persuade women to sell on commission, and testified that women were generally more interested in product lines like clothing, jewelry, and cosmetics that were usually sold on a noncommission basis, than they were in product lines involving commission selling like automo-tives, roofing, and furnaces. The contrary applied to men. Women were also less interested in outside sales which often required night calls on customers than were men, with the exception of selling custom draperies. Various reasons for women’s lack of interest in commission selling included a fear or dislike of what they perceived as cut-throat competition, and increased pressure and risk associated with commission sales. Noncommission selling, on the other hand, was associated with more social contact and friendship, less pressure and less risk. This evidence was confirmed by a study of national surveys and polls from the mid-1930’s through 1983 regarding the changing status of women in American society, from which a Sears’ expert made conclusions regarding women’s interest in commission selling; morale surveys of Sears employees, which the court found “demonstrate[ ] that noncommission saleswomen were generally happier with their present jobs at Sears, and were much less likely than their male counterparts to be interested in other positions, such as commission sales,” id. at 1310; a job interest survey taken at Sears in 1976; a survey taken in 1982 of commission and noncommission salespeople at Sears regarding their attitudes, interests, and the personal beliefs and lifestyles of the employees, which the court concluded showed that noncommission salesmen were “far more interested” in commission sales than were noncommission saleswomen, id. at 1312; and national labor force data. The court recognized the EEOC’s expert witness testimony regarding women’s general interests in employment, which essentially was that there were no significant differences between women and men regarding interests and career aspirations. We cannot determine the district court clearly erred in finding the evidence not credible, persuasive or probative. These expert witnesses used small samples of women who had taken traditional jobs when opportunities arose. Larger samples would have been more persuasive. In addition as the court found, “[n]one of these witnesses had any specific knowledge of Sears.” Id. at 1314. The court found Sears’ evidence clearly more persuasive on the issue of different interest in commission selling between men and women. The court also found significant Sears’ evidence that women became increasingly willing to accept commission sales positions between 1970 and 1980 due to, among other things, changes in commission sales positions from mostly full-time and largely part-time (more women preferred part-time), change in compensation to salary plus commission (which eliminated a lot of risk), increased availability of day care, and a group of successful saleswomen who served as role models. The EEOC attacks the court’s findings on interest on various grounds. We have already refuted the EEOC’s basic argument that Sears’ nonstatistical interest evidence is insufficient as a matter of law to successfully attack the EEOC’s statistical case. The EEOC further argues that its analysis of the Applicant Interview Guides (AIGs) quantified interest and provided more persuasive evidence of interest than Sears’ evidence on interest. According to the EEOC, the AIG analysis showed that while women were over 60% of full-time sales applicants and approximately 40% of the persons who considered themselves most ready, willing and able to sell installed home improvements jobs at Sears, women only comprised 1.7% of full-time commission sales hires in 1973 and between 10.6% and 5.3% thereafter. Sears argues in response that some of its evidence regarding interest, in the form of survey and labor force data, was indeed quantified. The district court gave little weight to the EEOC’s AIG analysis — we discuss our decision that the district court’s finding was not clearly erroneous in more detail at a later point. In short, the district court found that although neither the EEOC’s nor Sears’ analysis of the AIGs was entitled to much weight, Sears’ analysis was more helpful on the question of differences in interest for commission selling among men and women. The EEOC next argues that Sears maintained as part of its affirmative action program data on women refusing commission sales positions and that this would have provided an easy way of substantiating Sears’ interest arguments, but Sears did not introduce any of this evidence. Sears had introduced exhibit 25, however, which was a collection of documents on refusals and indications of lack of interest in commission sales from the Eastern Territory. The EEOC notes that this contains only eight instances of female outside applicants refusing positions throughout the period at issue. The court nonetheless found that this exhibit corroborated Sears’ witnesses’ testimony that there were sincere and extensive efforts to recruit women into commission sales. Furthermore, we find the district court did not clearly err in crediting the testimony of Sears’ store management witnesses regarding efforts to encourage women to take commission sales positions and women’s lack of interest in those positions. The EEOC bases another argument on the court’s finding that although the surveys and testimony preserved by Sears related primarily to the interests of women already employed by Sears, the evidence was also “a good indication of the interest of women applying for sales positions at Sears.” Sears II, 628 F.Supp. at 1312 n. 56. The EEOC argues that there is no basis in the record for this inference that noncommission sales employees’ interests were the same as those of women who applied for sales positions. But as we later discuss regarding the applicant pool, applicants’ interests were not clear and the EEOC did not distinguish among applicants who were interested in commission as opposed to noncommission selling. Furthermore, the EEOC’s own expert Siskin testified that fewer interested and qualified applicants for commission sales were to be expected in the applicant pool. If it is argued that there was no interest in commission selling only because there were no opportunities, which disputes Sears’ argument that there was instead an actual lack of interest in the existing opportunities, we are faced with the problem of which comes first, interest or opportunity, a chicken-egg problem. This is again an area where EEOC might have called a representative group of disappointed witnesses who preferred commission selling, but were rebuffed. It did not. In short, we hold that the district court did not clearly err in finding that women were not as interested in commission sales positions as were men. We similarly find that the district court did not clearly err in concluding that women applicants had different qualifications than did men applicants. The court noted that the EEOC’s Commission Sales Report indicated that “on average, female applicants in the ‘sales’ pool were younger, less educated, less likely to have commission sales experience, and less likely than male applicants to have prior work experience with the products sold on commission at Sears.” Sears II, 628 F.Supp. at 1315. The EEOC does not challenge this finding. All three of the court’s findings discussed above — that commission selling is significantly different from noncommission selling, that women were not equally interested with men in commission selling at Sears, and that women applicants were not equally qualified with men for commission selling at Sears — form the bases for the court’s criticisms of the EEOC’s statistics regarding hiring at Sears. 1. Applicant Pool The EEOC challenges the district court’s characterization of its applicant pool, which was the source of the EEOC’s hiring statistics, as “inflated.” The EEOC’s expert Siskin constructed this applicant pool from the employment applications of 33,000 rejected sales applicants from 33 randomly selected Sears stores, and the applications of approximately 1,920 persons hired into full-time and part-time commission sales positions between 1973 and 1980 at approximately 210 stores. With the data Siskin attempted to determine the characteristics of male and female applicants by coding information from the applications onto computer tapes; in addition, the EEOC attempted to estimate the female proportion of sales applicants at all Sears stores on a nationwide and territorial basis. To identify all commission sales hires and promotions for 1973 through 1980, the EEOC also analyzed Sears’ computerized payroll records for all Sears employees for those years. See Sears II, 628 F.Supp. at 1294. Using the payroll records, Siskin estimated the female proportion of full-time and part-time commission sales hires in the nation and each territory for each year from 1973 through 1980. To arrive at figures for the female proportion of full-time and part-time commission sales applicants, Sis-kin analyzed the sample of applications of nonhired applicants and counted as commission sales applicants all applicants who had applied for any job at Sears except those persons who requested only a nonsales job. The application, however, did not distinguish between commission and noncommission sales jobs. Siskin then compared the estimated percentages of women commission sales hires (“actual percent female”) with the percent of women in the “sales” applicant pool (“expected percent female”), on a nationwide and territorial basis for each year from 1973 through 1980. The district court found that “these comparisons resulted in large disparities between EEOC's actual and expected percent of female commission sales hires on a national and territorial basis for all years,” with the z values, or number of standard deviations between the actual and expected figures, in a “highly statistically significant” range nationwide as well as in individual territories. Sears II, 628 F.Supp. at 1296-96. The court initially criticized the EEOC’s applicant sales pool as “inflated” because Siskin included in the pool of applicants for sales positions anyone who had not checked “nonsales jobs only.” This meant that the EEOC considered as an applicant for a commission sales position anyone who had checked either “sales,” “any of the above,” or “sales” and another type of job (possibly including “nonsales” jobs). Furthermore, the court found that assuming “arbitrarily” that all members of the “sales” pool were applying for all commission sales positions at Sears in all divisions was “one of the most serious flaws pervading all of EEOC’s statistical analyses.” Id. at 1301. We agree with the district court’s conclusion that this led to an overinclusive sales pool, because it did not distinguish between commission selling and noncommission selling or account for differences in interests or qualifications among applicants. We also agree with the court’s conclusion that the EEOC “offered no credible evidence to support” either the assumption that all applicants who indicated any interest in sales were specifically interested in commission sales or the assumption that all members of the sales pool were ap