Use and Misuse of Expert Opinions at the Class ... - King & Spalding

Use and Misuse of Expert Opinions
at the Class Certification Stage
Use of expert opinions should not be permitted, but if courts continue to do so,
defendants must attack the expert’s qualifications and present their own
By Dwight J. Davis and
By Karen R. Kowalski
AS THE number of class actions in the
United States increases, so does the
device of employing expert witnesses to
give opinions at the class certification stage
as to the ultimate legal issues of manageability,
predominance and superiority, the
elements required in federal court by Rule
23 of the Federal Rules of Civil Procedure.
The use of experts at this stage of class
litigation is inappropriate. They should be
prohibited from testifying on the legal propriety
of class certification, but there are
ways of effectively countering their opinions
if they are allowed to testify.
IADC member Dwight J. Davis is a
partner in the New York office of King &
Spalding and has litigated many class actions.
He is a graduate of The Citadel
(B.A. 1975) and Mercer University (J.D.
1982). An associate in the New York office,
Karen R. Kowalski is a graduate of
Gonzaga University (B.A. 1997) and St.
John’s University (J.D. 2001).
The authors thank Kara Ong, an associate
in the Atlanta office of King &
Spalding, for her assistance in the preparation
of this article.
USING EXPERT TESTIMONY
TO ESTABLISH PROPRIETY
OF THE CLASS
Although case law has established that
the proponent of class certification has the
heavy burden of proving the elements of
Rule 23 and that the decision to certify a
class should be made only after the district
court has conducted a “rigorous analysis,”
courts have provided little guidance on
how a district court should conduct such an
analysis. 1 In recent years, U.S. federal
court judges have allowed class proponents
to meet this burden by proffering any and
all evidence or witnesses, including experts,
into the class certification record. 2
Plaintiffs’ attorneys are not the only ones
offering experts’ opinions at this stage.
Many defendants are beginning to do the
same to demonstrate that certification is inappropriate.
Generally, plaintiffs and defendants use
experts at the class certification stage in
two particular areas. First, whether variations
of state substantive law will hinder a
court’s ability to manage a multistate class
action, and second, whether the underlying
facts of the claims common to the entire
class predominate over individual claims in
Rule 23(b)(3) class actions.
A. Rule 23
Rule 23(a) provides that a class action
may be maintained only if the proponent
establishes that (1) the class is so numerous
that the joinder of members is impracticable;
(2) there are questions of law or fact
common to the entire class; (3) the claims
or defenses of the representative parties are
typical of those of the class; and (4) the
representative parties will fairly and adequately
protect the interests of the class. If
the proponent establishes each of these
1. Gen. Tel. Co. S.W. v. Falcon, 457 U.S. 147,
161 (1982); Castano v. Am. Tobacco Co., 84 F.3d
734, 740 (5th Cir. 1996). See also Lorna G.
Schofield & Jeffrey S. Jacobson, Circuits Split on
Factual Disputes in Class Actions, N.Y. L.J., Oct.
23, 2001, at 1 (hereinafter “Circuits Split”).
2. Linda S. Mullenix, Certification Burdens,
NAT’L L.J., July 3, 2000, at A14 (hereinafter “Certification
Burdens”).

Page 286 DEFENSE COUNSEL JOURNAL—July 2002
four factors, the district court directs its inquiry
into the propriety of the class under
one of the subsections of Rule 23(b). 3
In the usual case, plaintiffs will attempt
to proceed under either Rule 23(b)(2) if
they seek injunctive and declaratory relief,
or Rule 23(b)(3) if they seek monetary
damages. Sometimes both are employed.
While there is some overlap between the
elements of Rule 23(a) and (b)(3), the
plaintiff must meet the heavy burden under
Rule 23(b)(3) of showing that the class
action is the “superior” means of adjudicating
the dispute and that common issues of
law and fact “predominate” over individual
issues.
B. Used to Establish that Variations in
State Laws Does Not Create
Manageability Problems
In putative nationwide class actions,
variations in state law often prevent a federal
district court from finding the action
manageable, which results in a denial of
class certification. 4 The U.S. Supreme
Court has cautioned that a district court
“may not take a transaction with little or no
relationship to the forum and apply the law
of the forum in order to satisfy the procedural
requirements that there be a common
question of law.” 5
Often, courts find that any variations
among state laws defeat the predominance
of common legal issues and render a
23(b)(3) multistate class action unmanageable.
6 Defendants regularly defeat class
certification on a showing that divergent
state laws present “insuperable obstacles”
because the federal district court would be
required to apply different states’ laws to
the claims of class members and to instruct
jurors so that they will know which laws
apply to which claims. 7 As a result, plaintiffs
have employed experts to opine that
the variation among the laws of some 50
jurisdictions fail to predominate over
common legal issues, therefore making the
legal differences manageable—or even
non-existent. 8
For example, in In re Bridgestone/
Firestone Inc. Tires Products Liability Litigation
in the U.S. District Court for the
Southern District of Indiana, plaintiffs’ experts
opined that the divergent laws of the
states did not impinge on the manageability
of the class action. 9 In this class action,
customers brought a nationwide class action
alleging that tires on sport utility vehicles
were defectively designed or manufactured.
The named plaintiffs were
residents of 27 different states, and they
sought to represent two classes: (1) the
“tire class,” persons and entities in the
United States who own or lease or had
owned or leased vehicles that are or were
equipped with certain Firestone-brand
tires; and (2) the “Explorer diminution
class,” those who own or lease or had
3. Amchem Prods. v. Windsor, 521 U.S. 591,
613-14 (1997).
4. See, e.g., Castano, 84 F.3d 734.
5. Phillips Petroleum Co. v. Shutts, 472 U.S. 797,
821-23 (1985).
6. See, e.g., Amchem, 521 U.S. at 624; Zinser v.
Accufix Research Inst. Inc., 253 F.3d 1180, 1189
(9th Cir. 2001) (differences in state law compound
disparities among class members from different
states), opinion amended, 273 F.3d 1266 (9th Cir.
2001); In re Ford Motor Co. Ignition Switch Prods.
Liab. Litig., 194 F.R.D. 484, 490 (D. N.J. 2000);
Castano, 84 F.3d at 741.
7. See In re Sch. Asbestos Litig., 789 F.2d 996,
1010 (3d Cir. 1986), cert. denied, 479 U.S. 852
(1986) (granting conditional certification in spite of
state law variations, while noting the problem of
manageability); In re Gen. Motors Corp. Pick-Up
Truck Fuel Tank Prods. Liab. Litig., 55 F.3d 768,
815 (3d Cir. 1995), cert. denied, 516 U.S. 824
(1995) (overturning nationwide class settlement but
noting that courts have certified nationwide class actions
relying on capacity for court to decertify or
redefine class subsequently if case becomes unmanageable).
These cases, however, are the exception
rather than the norm. Courts overwhelmingly reject
any assurances by counsel that problems with predominance
or superiority caused by the application
of various state laws could simply be overcome. Ignition
Switch, 174 F.R.D. at 350; Castano, 84 F.3d at
742. Accord Andrews v. Am. Tel. & Tel. Co., 95
F.3d 1014, 1023 (11th Cir. 1996).
8. Joel S. Feldman et al., Expert Witnesses in Insurance
Class Actions and Individual Cases—Defense
Perspective, 80 A.L.I. 249, 271 (2000).
9. 155 F.Supp.2d 1069 (S.D. Ind. 2001) (granting
in part and denying in part defendants’ motion to
dismiss). In a separate order and opinion the same
day, the court ruled that the plaintiffs’ state-lawbased
claims seeking a judicial recall of tires were
pre-empted by the Motor Vehicle Safety Act, 49
U.S.C. § 30101 et seq. 153 F.Supp.2d 935.

Use and Misuse of Expert Opinions
owned or leased Ford Explorer sport-utility
vehicles, regardless of the tires with which
they were equipped.
Given that the classes encompassed persons
from numerous states with varying
laws, the court invited the parties to present
any facts relevant to the choice of law
analysis for class certification. The plaintiffs
offered the testimony of two experts,
both of whom allegedly were legal scholars.
One opined “that there [was] sufficient
uniformity across the states in order to try
the class claims in a singular proceeding.” 10
The defendants sought to strike the experts’
declarations, contending that it was
“improper to offer ‘expert’ opinions on legal
issues relevant to class certification.” 11
The district court ruled that the motion
to strike was moot, since the court had established
“sufficient boundaries” around
the proffered experts’ opinions, in order to
prevent the submissions from “imping[ing]
on [its] judgments or usurp[ing] [its] own
application of legal principles to the facts
and the issues.” 12 The court ultimately concluded
that the plaintiffs had met their burden
under Rule 23. 13
Fortunately, however, the Seventh Circuit
overruled the district court’s decision
to certify the classes, holding that the matter
was unmanageable as a nationwide
class action. 14 But unfortunately, while
roundly criticizing the trial court, the court
of appeals failed to address the use of experts
at this phase of the case. In an opinion
by Judge Easterbrook, it held that the
district court erred in granting class certification,
finding that Indiana’s choice-of-law
Page 287
rule selects the laws of the 50 states and
multiple territories where the buyers reside
and not the place of the defendant’s headquarters.
Thus, the court rejected the trial court’s
application of one state’s law to claims by
plaintiffs throughout the nation. The
claims, the court stated, must be adjudicated
under the laws of several jurisdictions,
thereby rendering the class unmanageable.
10. 205 F.R.D. 503, 511 (S.D. Ind. 2001); id. (citing
Pl. Mem. at 9 n.4).
11. In re Bridgestone/Firestone, Inc. Tires Prods.
Liab. Litig., No. IP 00-9373-C-B/S, MDL No. 1373
(S.D. Ind.), Defendants’ Memorandum of Law to
Strike the Declarations of Samuel Issacharoff and E.
Hunter Taylor (quoting Issacharoff Decl. 23), April
3, 2001.
12. Bridgestone/Firestone, No. IP 00-9373-C-B/
S, MDL No. 1373, Transcript of the Hearing on
Plaintiffs’ Motion for Class Certification, at 7-8,
Nov. 16, 2001.
13. 205 F.R.D. at 503 (S.D. Ind. 2001) (certifying
tire class, Explorer class, and Explorer subclass),
rev’d 2002 WL 831990 (7th Cir.) (single nationwide
class not manageable because claims must be adjudi-
C. Used to Establish that Common
Issues Predominate
Another significant hurdle to class certification
in a 23(b)(3) class action is
whether one set of underlying facts predominates
over individual facts that may
be relevant to a particular claim. As with
the case when legal variations exist, parties
have employed the testimony of experts to
opine on whether the facts underlying the
cause of action are common to each plaintiff.
A split among the federal courts of appeals
has developed as to whether and how
courts are to resolve factual disputes that
may affect a given case’s suitability for
class treatment. 15
For example, the Second Circuit has
adopted an extremely liberal construction
of Rule 23, accepting plaintiffs’ factual
allegations as true and refusing to sift
through disputed factual issues when considering
class certification. In In re Visa
Check/MasterMoney Antitrust Litigiation, 16
for example, the court articulated this principle.
In the district court, both parties introcated
under law of so many jurisdictions, and not
manageable even on statewide basis). See also 184
F.Supp.2d 826 (denying motion of Louisiana plaintiffs
to remand to Mississippi state court in which
they filed); 205 F.R.D. 535 (compelling deposition
of William Clay Ford Jr., chairman of board and
chief executive officer of Ford); and 2002 WL
463275 (denying defendants’ motion to dismiss Colombian
and Venezuelan actions of ground of forum
non conveniens).
14. 2002 WL 831990 (7th Cir. May 2, 2002). The
court also concluded that the class could not be certified
with subclasses in each of the 50 states.
15. Circuits Split, supra note 1, at 1.
16. 192 F.R.D. 68 (E.D. N.Y. 2000).

Page 288 DEFENSE COUNSEL JOURNAL—July 2002
duced expert reports to support their respective
positions in favor of and in opposition
to class certification. The experts
gave competing views on whether
a method could be devised to litigate
the plaintiffs’ complex antitrust claims,
thus avoiding individualized trials. The
court disregarded the fact that the experts
who testified offered opposing views on
whether the facts of the case were susceptible
to class-wide proof. Instead, it held
that the expert testimony offered by the
plaintiffs was admissible for the “narrow
purpose” of supporting their class certification
motion. Moreover, the court stated,
simply because the defendants and their
expert disagreed with the plaintiffs’ expert
conclusions was not a basis for denying
class certification. 17
The Second Circuit agreed with the district
court, holding that a district court may
not weigh the conflicting expert evidence
at the class certification stage. 18 Rather, at
that stage, the district court needs to inquire
only “whether plaintiffs’ expert evidence
is sufficient to demonstrate common
questions of fact warranting certification of
the proposed class.” The court also rejected
the defendants’ contention that the plaintiffs’
expert evidence failed to provide a
reliable basis for class certification. It concluded
that on a finding that an expert’s
methodology is not fatally flawed, it is
“sufficiently reliable for class certification
purposes.” The court neither defined “fatally
flawed” nor provided an analysis as to
how a district court should make such a
determination.
This Second Circuit opinion leads one to
believe that all a plaintiff needs to do to get
a class certified is to show up at the courthouse
with a witness who will parrot the
right phrases.
Other U.S. courts of appeals have not
been so lenient to class action plaintiffs in
deciding a class certification motion. The
Third 19 and Fifth 20 circuits have concluded
that when parties dispute the facts central
to class certification, judges “must make a
preliminary inquiry into the merits . . . to
determine whether the alleged claims can
be properly resolved as a class action.” 21
This reasoning is consistent with the U.S.
Supreme Court’s holding in General Telephone
Co. Southwest v. Falcon. 22
For example, in Newton v. Merrill
Lynch, Pierce, Fenner & Smith Inc., the
Third Circuit affirmed a district court’s
finding that the plaintiffs had failed to
prove the predominance and superiority requirements
of subsection 23(b)(3). 23 Thousands
of investors sued their broker-dealers
for securities fraud in “breaching their duty
of best execution” under Rule 10b-5 of the
Securities and Exchange Act. The parties
disputed whether the elements of reliance
and economic loss under 10b-5 were
unique or common to each investor. The
plaintiffs’ expert provided a sworn declaration
predicting that he could devise a formula
that would measure the amount of
damages among the class members and
also serve as a plan for allotment. Defendants
contended that economic loss could
not be presumed across the entire class
given that reliance and economic loss were
linked with each trade and/or would require
individual treatment given that hundreds
of trades occurred everyday.
The Third Circuit rejected the plaintiffs’
expert’s testimony that a formula could be
developed. It agreed with the district
court’s finding that the individual question
of whether each class member suffered
economic injury was an “insurmountable
obstacle” to certification. Thus, it denied
17. Id. at 74-76, 78.
18. 280 F.3d 124 (2d Cir. 2001).
19. See, e.g., Johnston v. HBO Film Management
Inc., 265 F.3d 178 (3d Cir. 2001) (reaffirming that
courts must base certification decisions on underlying
facts and not solely on plaintiffs’ allegations).
20. See, e.g., Castano, 84 F.3d 734 (decertifying
class and finding little support in plaintiffs’ evidence
that district court would be able to manage divergent
state laws and that common facts predominated over
individual ones).
21. Newton v. Merrill Lynch, Pierce, Fenner &
Smith Inc., 259 F.3d 154, 166 (3d Cir. 2001);
Johnston, 265 F.3d at 186; Szabo v. Bridgeport Machines
Inc., 249 F.3d 672, 676 (7th Cir. 2001).
22. 457 U.S. 147, 160 (1982).
23. 259 F.3d 154 (3d Cir. 2001).

Use and Misuse of Expert Opinions
class certification, concluding that “actual
economic loss on the part of each investor
would involve individual questions that
predominate over common ones.” 24
Page 289
D. A “Rigorous Analysis” Does Not
Require Expert Testimony
Courts have broad discretion in deciding
whether to certify a class. 25 Nevertheless,
the discretion must be exercised within the
framework of Rule 23. 26 The U.S. Supreme
Court has not given any guidance on the
“rigorous analysis” of the Rule 23 prerequisites
that should be applied by district
courts. 27 As a result, district courts have developed
varying processes, often involving
evidentiary hearings before determining
whether the action demands class action
treatment. 28
It is important to note that Rule 23 does
not specifically provide for or require a
certification hearing. The problem with
district courts having broad discretion in
determining whether to certify a class does
not lie with the development of sophisticated
processes, such as elaborate evidentiary
hearings, but rather with allowing expert
testimony to be offered as part of the
certification record. In some cases, the issues
may be plain enough from the pleadings
to determine that the plaintiffs have
met the burden of proof and established
that the class satisfies the mandates of Rule
23. More often than not, however, the issues
are not so apparent, so that a district
court is forced to look beyond the pleadings
to “understand the claims, defenses,
relevant facts, and applicable substantive
law in order to make a meaningful determination
of the certification issues.” 29
Originally, in Eisen v. Carlisle &
Jacquelin, the U.S. Supreme Court stated
that a court should not evaluate the merits
of the parties’ legal or factual claims on a
motion for class certification. 30 Four years
later however, in Coopers & Lybrand v.
Livesay, the Court stepped away from this
bright-line proposition and concluded that
many of the questions involved in determining
the appropriateness of class certification
are “intimately” involved with the
merits. 31
In Szabo v. Bridgeport Machines Inc.,
the Seventh Circuit endorsed the idea that a
district court should examine the merits of
a suit at the certification stage, but only to
the extent that such an inquiry is necessary
to determine whether class certification is
appropriate. 32 The court reversed the district
court’s certification of a nationwide
class of persons alleging a breach of warranty.
It held that the district court had
erred in certifying the class based solely on
the allegations in the plaintiffs’ complaint.
Thus, it limited the district court’s discretion,
which operated in favor of class
action plaintiffs. Before a court decides
whether to allow a case to proceed as a
class action, the court declared, the judge
should make “whatever factual and legal
inquiries [that] are necessary under Rule
23.” 33
Although Coopers & Lybrand and Szabo
sanction looking beyond the plaintiffs’
pleadings at the class certification stage,
they do not imply that district courts
should or need to rely on the opinions of
“legal experts” to aid it in making the
24. Id. at 188.
25. See, e.g., City of New York v. Int’l Pipe &
Ceramics Corp., 410 F.2d 295, 300 (2d Cir. 1969).
26. Gulf Oil Co. v. Bernard, 452 U.S. 89, 100
(1981).
27. Gen. Tel. Co. S.W. v. Falcon, 457 U.S. 147,
161 (1982).
28. Certification Burdens, supra note 2, at A14.
29. Castano, 84 F.3d at 744.
30. 417 U.S. 156, 178 (1974).
31. 437 U.S. 463, 469 & n.12 (1978). See also
Love v. Turlington, 733 F.2d 1562, 1564 (11th Cir.
1984); Huff v. N.D. Cass Co., 485 F.2d 710, 713
(5th Cir. 1973) (en banc).
32. 249 F.3d 672, 675 (7th Cir. 2001) (explaining
that “proposition that a district judge must accept all
of the complaint’s allegations when deciding
whether to certify class cannot be found in Rule
23"); Newton, 259 F.3d at 154, 166 (3d Cir. 2001).
See also 5 MOORE’S FEDERAL PRACTICE § 23.64[4]
(“[B]ecause the determination of a certification request
invariably involves some examination of factual
and legal issues underlying the plaintiffs’ cause
of action, a court may consider the substantive elements
of the plaintiffs’ case in order to envision the
form that a trial on those issue would take.”).
33. Szabo, 249 F.3d at 676.

Page 290 DEFENSE COUNSEL JOURNAL—July 2002
determination that the class has met the requirements
for certification. These decisions
merely state that in order to understand
the claims, defenses, relevant facts
and applicable substantive law, a district
court should make every necessary legal
and factual inquiry. It is inconceivable that
these cases suggest the use of inadmissible
evidence in a class certification inquiry. In
neither Coopers & Lybrand nor Szabo did
the parties offer expert opinions at the certification
stage
PROHIBITING EXPERT
TESTIMONY UNDER
TRADITIONAL RULES OF
EVIDENCE ANALYSIS
Rule 702 of the Federal Rules of Evidence
provides: “If scientific, technical, or
other specialized knowledge will assist the
trier of fact to understand the evidence or
to determine a fact in issue, a witness
qualified as an expert . . . may testify
thereto.” Under a Rule 702 analysis, experts
should be prohibited from testifying
at the class certification stage, as they are
opining on questions of law rather than
questions of fact. An expert’s testimony is
neither helpful nor necessary for a court
when it dissects issues of law. 34
A. Legal Experts
Although it is well settled that experts
may provide an opinion to aid a jury or
judge to comprehend complex facts, experts
may not testify as to the ultimate
legal conclusions based on those facts. 35
Every federal court of appeals has agreed
that an expert is prohibited from testifying
as to issues of law. “[T]he majority rule is
so well-established that it is often deemed
a basic premise or assumption of evidence
law—a kind of axiomatic principle.” 36
Moreover, the language of Rule 702 does
not provide for expert testimony for any
purpose other than to help the trier of fact
understand the factual material presented
by the parties during trial.
Even under a broad interpretation of
Rule 702, expert testimony on legal issues
should be prohibited. This interpretation is
reasonable for two reasons. First, the district
court’s determination of whether the
movant has met the criteria of Rule 23 for
class treatment is a legal question, not one
of fact. 37 Second, class certification does
not require a trier of fact; a motion for
class certification is not a trial. 38
Indeed, although, the issue of class treatment
is a legal question, courts nevertheless
have repeatedly allowed plaintiffs and
defendants alike to offer expert opinions
into the record at certification. This practice
ignores certain basic realities of modern
litigation. 39
1. Under Guise of Avoiding Battle of
Experts, Courts Leave the Field
to Plaintiffs
Courts often are presented with the problem
of how much weight to give to one
expert over another. This so-called “battle
of the experts” is an issue that will continue
to trouble courts as long as experts
are used at the certification stage. Federal
courts have varying views on this issue, but
a curious analysis has developed in some
circuits. In these circuits, courts state that a
34. For example, in In re Initial Public Offering
Securities Litig., 174 F.Supp.2d 61, 64 (S.D. N.Y.
2001), the district court denied the admissibility of
expert opinions on an issue of law. The defendants
moved to recuse the court. In support of their motion,
the defendants proffered the affidavits and declarations
of two experts in judicial ethics. The district
court rejected the contention that the experts’
opinions were admissible, concluding that Rule 702
prohibits such use.
35. United States v. Bilzerian, 926 F.2d 1285,
1294 (2d Cir. 1991).
36. Thomas Baker, The Impropriety of Expert
Witness Testimony on the Law, 40 U. KAN. L. REV.
325, 352 (1992). See, e.g., Initial Public Offering,
174 F.Supp.2d at 64 (concluding that expert on judicial
ethics cannot opine on judge’s recusal, given
that it is issue of law).
37. Schenek v. FSI Futures Inc., 1998 WL
427625, at *4 (S.D. N.Y.) (“[T]he question whether
to certify class is one of law, resting in district
court’s discretion, and falling outside the usual legitimate
boundaries of expert opinion testimony.”)
38. Visa Check/MasterMoney, 192 F.R.D. at 68,
76.
39. See Note, Expert Legal Testimony, 97 HARV.
L. REV. 797, 808-11 (1984).

Use and Misuse of Expert Opinions
contest between experts is inappropriate at
the certification stage, but at the same time
they admit expert testimony. 40 In Visa
Check/MasterMoney, for example, the
court asserted, “a court at the class certification
stage should not delve into the merits
of an expert’s opinion, or indulge in
‘dueling’ between opposing experts.” 41 Indeed,
if the court believes that the mere
appearance of experts on both sides means
that the plaintiff wins, there will be no “dueling.”
The result of that approach is that the
district courts consider only plaintiffs’ expert
testimony for certification purposes
and reserve the effectiveness of defendants’
expert for trial on the merits. 42 In In
re Disposable Contact Lens Antitrust Litigation,
a federal district court in Florida
stated that although the defendants’ expert
disagreed with the “methodologies and
conclusions propounded” by the plaintiffs’
expert, it “is no reason to deny class certification.”
43 The court went on to certify the
class based on the plaintiffs’ expert’s unquestioned
and unchallenged opinion.
Class certification is not a Rule 12(b)(6)
motion to dismiss, where the judge must
accept plaintiff’s factual allegations in the
complaint as true. 44 The approach epitomized
by Disposable Contact Lens is naïve
at best and leads to the in terrorem effect
and abuse of the class process at worst. An
order certifying a class is usually the district
court’s last word on the matter. If the
class is certified, many defendants succumb
to the pressures of entering into a
“reasonable” settlement, even if exorbitant,
rather than risking the potential of a massive,
adverse jury verdict.
Page 291
2. Inherent Bias
A litigant’s choice of expert is purely
strategic. Competent attorneys make every
effort to choose an expert who can most
accurately support their legal theories, and
parties retain those experts whose viewpoints
support their allegations. Parties
may contact several “consulting experts”
before finding one whose methodology is
most compatible with their legal theory.
Therefore, the admission of experts at the
certification stage is fruitless, because neither
party will introduce an expert who
does not substantiate its argument for or
against class certification.
Courts either should reject the use of expert
testimony at the class certification
stage altogether or institute a means of sifting
through experts’ opinions in order to
ensure that there is minimal bias in certifying
a class.
B. Expert Testimony Does Not Assist
Fact Finder at Class Certification
Stage
It is well settled that experts’ opinions as
to issues of law are improper and usurp the
role of the judge. 45 The role of an expert
under Rule 702 of the Federal Rules of
Evidence is limited to the interpretation
and explanation of certain evidence in a
case for the benefit of laymen “fact finders.”
46 The special legal knowledge of the
judge renders expert testimony on legal issues
at the certification hearing superfluous
and unhelpful. 47 If the court needs advice
40. See, e.g., O’Connor v. Boeing North Am.
Inc., 184 F.R.D. 311, 324 n.16 (C.D. Cal. 1998)
(noting difference between parties experts’ theories
relating to merits of claims, and court will not engage
in “battle of the experts” at certification stage);
Krueger v. New York Tel. Co., 163 F.R.D. 433, 440-
41 (S.D. N.Y. 1995).
41. 192 F.R.D. at 76. See generally In re Industrial
Diamonds Antitrust Litig., 167 F.R.D. 374, 384
(S.D. N.Y. 1996) (“[I]t is for the jury to evaluate[]
conflicting evidence and to determine what weight to
give expert’s conclusions.”); In re Potash Antitrust
Litig., 159 F.R.D. 682, 696-97 (D. Minn. 1995)
(concluding that certification stage not proper forum
in which to resolve battle of the experts). See also
Black v. Rhone-Poulenc Inc., 173 F.R.D. 156, 162 &
n.6 (S.D. W.Va. 1996) (stating any challenges to experts’
findings would be determined after certification
stage).
42. See In re Polypropylene Carpet Antitrust
Litig., 996 F.Supp. 18, 26 (N.D. Ga. 1997).
43. 170 F.R.D. 524, 531 (M.D. Fla. 1996).
44. Szabo, 249 F.3d at 672, 676.
45. Meineker v. Hoyts Cinemas Corp., 154
F.Supp.2d 376, 379 (N.D. N.Y. 2001); Gregro v.
Barthel, 1996 WL 428819, *1 (E.D. Pa.).
46. Daubert v. Merrell Dow Pharmaceuticals
Inc., 509 U.S. 579, 591-92 (1993). It should be noted
that in regard to fact finding, the judge is also a
layman in need of assistance.

Page 292 DEFENSE COUNSEL JOURNAL—July 2002
on legal issues, the advocates in the case
should provide enlightenment on both
sides of the issue.
The judge has the knowledge and expertise
to dissect the most complex of legal
issues, without drawing on the opinion of a
hired “legal expert” who has developed a
methodology that substantiates the parties’
contentions on whether the facts underlying
the case predominate or that the variations
between state laws in a multistate
class action are manageable. If the parties
are not represented by sophisticated, wellpracticed
counsel who are able to articulate
why and how a class should or should not
be certified, there are serious issues raised
about the adequacy of class counsel. 48
Thus, experts on the elements of Rule 23
should be prohibited under the purview of
Rule of Evidence 702, and certification issues
should be left within the purview of
the judge.
DAUBERT/KUMHO TIRE
STANDARD SHOULD APPLY AT
CLASS CERTIFICATION STAGE
If expert testimony is used at class certification
stage, there must be assurances of
its reliability. The Daubert/Kumho Tire
standard should be applied at this stage.
A. Some Courts Have Rejected
Daubert/Kumho Tire Standard
At a trial on the merits, a federal district
court’s finding that the expert’s testimony
is admissible depends on whether the proponent
has satisfied the requirements of
Daubert v. Merrell Dow Pharmaceuticals
Inc. 49 and Kumho Tire Co. v. Carmichael. 50
The trial court is to act as a “gatekeeper” to
prevent experts from testifying if (1) they
are not qualified, (2) their opinions are not
subject to empirical proof or (3) the opinion
does not logically follow from the
evidence. Nevertheless, courts are uncertain
whether the Daubert and Kumho Tire
standard applies at the class certification
stage. 51
Some courts have concluded the Daubert/Kumho
Tire inquiry is completely unnecessary
with regard to class certification,
52 while others suggest that some type
of inquiry is necessary but have not required
a Daubert level of scrutiny. For example,
in Visa Check/MasterMoney, the
court concluded a Daubert inquiry is not
necessary at the preliminary stages of an
action, such as during a class certification
motion, since the purpose of a Daubert inquiry
is to shield the fact-finder at trial
from flawed evidence. The court found
there was no reason to protect it from
flawed evidence because class certification
is not a trial. Instead, it rejected the defendants’
contention that Daubert was the applicable
standard and applied a “limited”
analysis to support the admissibility of the
plaintiffs’ expert testimony. 53
The U.S. District Court for the Northern
District of Georgia created its own test in
In re Polypropylene Carpet Antitrust Liti-
47. See VII WIGMORE ON EVIDENCE § 1952, at
81; 3 CORBIN ON CONTRACTS § 554, at 227 (1960).
48. See, e.g., In re Asbestos Litig., 90 F.3d 963,
977 (5th Cir. 1996) (“A district court may not certify
a class without concluding that class counsel are
qualified, experienced and generally able to conduct
the proposed litigation.”)
49. 509 U.S. 579 (1993).
50. 526 U.S. 137 (1999).
51. While the focus of this article is on federal
actions where the Daubert/Kumho Tire standard applies,
in state actions, practitioners should not ignore
similar attacks that can be made under the appropriate
state standards. The authors of this article were
successful in two separate state actions in keeping
out plaintiff’s expert testimony under essentially a
Frye standard. In both, the plaintiffs’ experts applied
methodologies that had not been recognized by their
peers.
52. Visa Check/MasterMoney, 192 F.R.D. at 68,
76. See also O’Connor v. Boeing North Am. Inc.,
184 F.R.D. 311, 321 n.7 (C.D. Cal. 1998); Polypropylene
Carpet, 996 F.Supp. at 18, 26 (agreeing that
Daubert analysis was necessary to determine admissibility
of expert’s testimony but finding inquiry unnecessary
at certification stage).
53. 192 F.R.D. at 76-78. See also Vickers v. Gen.
Motors Corp., 204 F.R.D. 476 (D. Kan. 2001) (explaining
that, while Daubert analysis not required at
class certification stage, class should not be certified
“on basis of an expert opinion so flawed that it is
inadmissible as a matter of law”). But see Sanneman
v. Chrysler Corp., 191 F.R.D. 441, 451 & n.16 (E.D.
Pa. 2000) (during certification hearing, court found
that expert qualified under Daubert after hearing oral
argument on defendant’s Daubert motion; nevertheless,
court found that testimony was insufficient to
satisfy Rule 23).

Use and Misuse of Expert Opinions
gation. 54 The plaintiffs sought damages and
equitable relief pursuant to the Clayton Act
to remedy alleged violations of the Sherman
Antitrust Act arising from a conspiracy
alleged to have artificially maintained
the price of polypropylene carpet.
Both parties introduced experts to testify
whether the artificially inflated price lists
were common to all plaintiffs.
The court concluded that at this stage,
whether an expert’s opinion is admissible
does not necessitate a Daubert inquiry.
Rather, it set forth a three-part test to determine
the admissibility of an expert’s testimony
for class certification purposes, under
which the court evaluates whether the
expert’s testimony (1) is in alignment with
other principles within the same field, (2)
will posses probative value and (3) will
primarily use common evidence. The
court, relying on the plaintiffs’ expert opinion,
concluded that the plaintiffs had satisfied
their burden of showing that the antitrust
impact was common to all members
of the proposed class. 55
Page 293
ity and relevance of expert opinions. 56 The
Visa Check/MasterMoney court concluded
it was not a trier of fact at a certification
hearing, given that it is forbidden to engage
in an inquiry into the merits of the case. 57
A Daubert inquiry is not, however, an
evaluation of the merits. Its purpose is not
to seek out the truth—it is to protect the
judicial process from flawed testimony and
fraud. At the certification stage, the court is
drawing a conclusion whether the particular
prerequisites mandated under Rule 23
have been proved in order for the parties to
continue to the trial phase. The purpose of
Daubert is just as applicable at this stage as
it is at trial. By engaging in a Daubert inquiry,
the court can verify the expert’s
opinion, thereby preventing a party from
offering any witness simply to substantiate
its argument for or against class certification.
Second, certification cannot stand if the
district court finds during trial that the
expert’s opinion or methodology, which
led to the expert’s conclusion that the court
would be able to manage the claims under
divergent state laws or that the facts underlying
the claims predominated throughout
the entire class, does not pass a Daubert
inquiry. 58 The time and expense the court
has taken to hear the action could have
been avoided. By simply engaging in a
Daubert inquiry, the court could have denied
certification early in the litigation.
Class action litigation is a procedural
tool implemented to conserve judicial resources
by combining numerous individual
suits when possible. 59 When classes are
certified based on an expert’s opinion that
the action was manageable or that the underlying
facts predominated throughout the
class, when that expert’s opinion is later
54. 996 F.Supp. 18 (N.D. Ga. 1997).
55. Id. at 25-29.
56. 509 U.S. at 592-93 (1993). See also Michelle
Michelson, The Admissibility of Expert Testimony on
Battering and Its Effect after Kumho Tire, 79 WASH
U. L.Q. 367, 384 (2001).
57. 192 F.R.D. at 76.
58. Some courts have certified a class with the
understanding that if the case became unmanageable,
the court reserved the right to decertify or redefine
B. Daubert/Kuhmo Tire
Test Should Apply
Rejection of the Daubert/Kuhmo Tire
standard to evaluate the admissibility of
experts’ opinions at the certification stage
is incorrect for two reasons. First, the underlying
purpose of the establishment of
the Daubert test applies at the class certification
stage. Second, the absence of any
evaluation of experts at class certification
stage poses a threat of wasted judicial resources.
First, the Supreme Court intended the
Daubert inquiry to shield a trier of fact
from flawed evidence and to act as a
gatekeeping function to ensure the reliabilthe
class. See In re Gen. Motors Corp. Pick-Up
Truck Fuel Tank Prods. Liab. Litig., 55 F.3d 768,
815 (3d Cir. 1995), cert. denied, 516 U.S. 824
(1995); In re School Asbestos Litig., 789 F.2d 996,
1011 (3d Cir. 1986), cert. denied, 479 U.S. 852
(1986).
59. Alan S. Kaplinsky, Arbitration and Class Actions—A
Contradiction in Terms, 81 A.L.I. 173, 183
(2001).

Page 294 DEFENSE COUNSEL JOURNAL—July 2002
found to be based on unreliable conclusions
or theories, the class action vehicle is
not the most efficient means of proceeding.
PRACTICAL ADVICE ON
ATTACKING EXPERTS AT
CLASS CERTIFICATION STAGE
Despite the increased employment by
plaintiffs of experts to opine on issues of
law in support of motions for class certification,
there are a number of legal tactics
available to defense counsel to nullify the
expert’s opinion. Defense counsel can attack
plaintiff’s expert witness effectively
on several levels at the class certification
stage.
A. Attack on Legal Basis
Defense counsel should attack an expert’s
testimony on a legal basis, arguing
that: (1) the plaintiff’s expert is testifying
to issues of law, which is prohibited under
Evidence Rule 702, and (2) there is no legal
precedent that calls for the opinion of a
“legal expert” to aid the court in making
the determination that the class is appropriate
for certification.
This attack can be employed early in the
litigation and should be considered as soon
as the expert is identified. Because it is
based on a legal objection, there is no need
even to depose the expert. Although this
legal tactic has been virtually untapped, it
remains a strong argument because it establishes
that there is no foundation that
would allow experts to testify at class certification
hearings. If the expert is knocked
out early, the plaintiffs’ likelihood of obtaining
certification of the case may evaporate.
B. Establish that Expert Does Not
Qualify under Daubert
Although the federal courts of appeals
have not embraced Daubert in the class
certification context, defendants should
challenge the expert testimony offered in
support of plaintiff’s motion for class certification
on the ground that the expert does
not qualify under Daubert. In Visa Check/
MasterMoney, the district court rejected
the idea that a formal Daubert inquiry
should be applied at the certification stage.
Nonetheless, it stated that “there is a [limited]
role for a Daubert inquiry at this
stage,” thereby leaving defense counsel
with the opportunity to raise the issue of
the admissibility of the expert’s opinion. 60
The court also stated that the standard
for whether a court should admit expert
testimony at the certification stage turns on
whether the “expert opinion [is] so flawed
that it is inadmissible as a matter of law.”
In order for defense counsel to establish
that the testimony is suitably “flawed,” the
district court hinted that counsel must demonstrate
that: (1) plaintiff’s expert has no
qualifications that would establish him as
an expert to testify on such an issue, and
(2) plaintiff’s expert “failed to rely upon
the type of methodology and data typically
used and accepted in such cases.” 61
The jurisprudence on the admissibility
of expert opinions on issues relevant to determining
class certification is still evolving.
Thus, it is necessary for defense counsel
to continue to raise a Daubert motion at
the certification stage. That motion also
has the benefit of bringing to the attention
of the court some of the problems that are
associated with certifying the class. 62
60. 192 F.R.D. 68, 76-78. The court raised two
arguments that defendants had failed to make that in
sum may have shown that the expert’s opinion was
the kind of “junk science that a Daubert inquiry at
this preliminary stage ought to screen.”
61. Id. at 78. See also Ignition Switch, 194
F.R.D. at 493-94. Here, the defendant did not make a
Daubert motion but provided evidence to show how
the plaintiff’s expert used a technique that ran
counter to accepted statistical norms. The court inter
alia made note of the concerns raised by the defendants
and denied class certification.
62. See Alice A. Kelly & Joy L. Holley, Using
Daubert to Oppose Class Action Certification, 4
ANDDLR 6 (2001) (hereinafter “Using Daubert”).
Kelly and Holley explain that in Sanneman, 191
F.R.D. 441, the court heard oral argument on the
defendant’s motion to strike or exclude expert testimony.
While the court ultimately denied the motion,
it was an effective legal tactic, highlighting several
reasons why class certification was not appropriate
and leading the court to find that class treatment was
not right for this case.

Use and Misuse of Expert Opinions
If the court refuses to hear the Daubert
argument, counsel should consider “making
the record” to show what would have
been introduced at the hearing. The recent
amendment to Rule 23 provides for interlocutory
appeal of class certification decisions,
making it possible that the issue of
the applicability of Daubert at the class
certification stage should be reviewed on
appeal before the case has gone all the way
to judgment.
C. Offer Your Own Expert
Even in those courts that have said they
will not entertain a “battle of the experts,”
defense counsel should make its record on
this issue by offering its own expert. This
forces the court to examine, and the plaintiff
to defend, the reliability and the methodology
employed by the plaintiff’s expert.
63
For example, in In re Ford Motor Co.
Ignition Switch Products Liability Litigation,
the plaintiffs sought to certify a class
alleging injuries from defective ignition
switches. 64 To prove the predominance element
of Rule 23(b)(3), the plaintiffs offered
the opinion of an expert statistician to
show that common factual issues predominated
over the class. In response, the defendant
employed its own statistical expert.
The experts offered opposing opinions.
The concerns raised by the defendant’s expert,
as well as the district court’s own
concerns regarding the reliability of plaintiffs’
expert’s data, caused the district court
Page 295
to find that plaintiffs had not met their burden
under Rule 23.
The use of a defense expert to attack not
only the plaintiff’s expert’s opinion, but
also the data and methodology used
to form that opinion, can be a valuable
weapon to nullify the effect of plaintiffs’
use of an expert’s opinion at the class certification
stage.
CONCLUSION
The issue of whether experts should be
allowed to testify at the certification stage
is still open for debate. Without guidance
from the U.S. Supreme Court as to what
evidence should be utilized to conduct a
“rigorous analysis,” trial courts have taken
it on themselves to assume experts are appropriate.
It is reasonable to conclude that
the use of experts to opine on legal issues
at the class certification stage is not permitted
under the Federal Rules of Evidence. A
judge’s role is clearly usurped by having
legal experts testify on legal questions,
which are exclusively within the purview
of the judge.
The rule is quite clear and has been uniformly
interpreted until now. Given the
growth, scale and in terrorem effect of
class action litigation in the United States,
this is an issue that demands immediate attention
from the trial courts, legal scholars
and practitioners.
63. Using Daubert, supra note 61.
64. 194 F.R.D. 484 (D. N.J. 2000).