Tyson Foods, Inc. v. Bouaphakeo

(Slip Opinion) OCTOBER TERM, 2015 1

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader.

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.

SUPREME COURT OF THE UNITED STATES

Syllabus

TYSON FOODS, INC. v. BOUAPHAKEO ET AL.,

INDIVIDUALLY AND ON BEHALF OF ALL OTHERS SIMILARLY

SITUATED

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR

THE EIGHTH CIRCUIT

No. 14–1146. Argued November 10, 2015—Decided March 22, 2016

Respondents, employees of petitioner Tyson Foods, work in the kill, cut,

and retrim departments of a pork processing plant in Iowa. Re-

spondents’ work requires them to wear protective gear, but the exact

composition of the gear depends on the tasks a worker performs on a

given day. Petitioner compensated some, but not all, employees for

this donning and doffing, and did not record the time each employee

spent on those activities. Respondents filed suit, alleging that the

donning and doffing were integral and indispensable to their hazard-

ous work and that petitioner’s policy not to pay for those activities

denied them overtime compensation required by the Fair Labor

Standards Act of 1938 (FLSA). Respondents also raised a claim un-

der an Iowa wage law. They sought certification of their state claims

as a class action under Federal Rule of Civil Procedure 23 and certifi-

cation of their FLSA claims as a “collective action.” See 29 U. S. C.

§216. Petitioner objected to certification of both classes, arguing that,

because of the variance in protective gear each employee wore, the

employees’ claims were not sufficiently similar to be resolved on a

classwide basis. The District Court concluded that common ques-

tions, such as whether donning and doffing protective gear was com-

pensable under the FLSA, were susceptible to classwide resolution

even if not all of the workers wore the same gear. To recover for a

violation of the FLSA’s overtime provision, the employees had to

show that they each worked more than 40 hours a week, inclusive of

the time spent donning and doffing. Because petitioner failed to keep

records of this time, the employees primarily relied on a study per-

formed by an industrial relations expert, Dr. Kenneth Mericle. Mer-

2 TYSON FOODS, INC. v. BOUAPHAKEO

Syllabus

icle conducted videotaped observations analyzing how long various

donning and doffing activities took, and then averaged the time taken

to produce an estimate of 18 minutes a day for the cut and retrim de-

partments and 21.25 minutes for the kill department. These esti-

mates were then added to the timesheets of each employee to ascer-

tain which class members worked more than 40 hours a week and the

value of classwide recovery. Petitioner argued that the varying

amounts of time it took employees to don and doff different protective

gear made reliance on Mericle’s sample improper, and that its use

would lead to recovery for individuals who, in fact, had not worked

the requisite 40 hours. The jury awarded the class about $2.9 million

in unpaid wages. The award has not yet been disbursed to individual

employees. The Eighth Circuit affirmed the judgment and the

award.

Held: The District Court did not err in certifying and maintaining the

class. Pp. 8–17.

(a) Before certifying a class under Rule 23(b)(3), a district court

must find that “questions of law or fact common to class members

predominate over any questions affecting only individual members.”

The parties agree that the most significant question common to the

class is whether donning and doffing protective gear is compensable

under the FLSA. Petitioner claims, however, that individual inquir-

ies into the time each worker spent donning and doffing predominate

over this common question. Respondents argue that individual in-

quiries are unnecessary because it can be assumed each employee

donned and doffed for the same average time observed in Mericle’s

sample.

Whether and when statistical evidence such as Mericle’s sample

can be used to establish classwide liability depends on the purpose

for which the evidence is being introduced and on “the elements of

the underlying cause of action,” Erica P. John Fund, Inc. v. Hallibur-

ton Co., 563 U.S. 804, 809. Because a representative sample may be

the only feasible way to establish liability, it cannot be deemed im-

proper merely because the claim is brought on behalf of a class. Re-

spondents can show that Mericle’s sample is a permissible means of

establishing hours worked in a class action by showing that each

class member could have relied on that sample to establish liability

had each brought an individual action.

Anderson v. Mt. Clemens Pottery Co., 328 U. S. 680, shows why

Mericle’s sample was permissible in the circumstances of this case.

There, where an employer violated its statutory duty to keep proper

records, the Court concluded the employees could meet their burden

by proving that they in fact “performed work for which [they were]

improperly compensated and . . . produc[ing] sufficient evidence to

Cite as: 577 U. S. ____ (2016) 3

Syllabus

show the amount and extent of that work as a matter of just and rea-

sonable inference.” Id., at 687. Here, similarly, respondents sought

to introduce a representative sample to fill an evidentiary gap creat-

ed by the employer’s failure to keep adequate records. Had the em-

ployees proceeded with individual lawsuits, each employee likely

would have had to introduce Mericle’s study to prove the hours he or

she worked. The representative evidence was a permissible means of

showing individual hours worked.

This holding is in accord with Wal-Mart Stores, Inc. v. Dukes, 564

U. S. 338, where the underlying question was, as here, whether the

sample at issue could have been used to establish liability in an indi-

vidual action. There, the employees were not similarly situated, so

none of them could have prevailed in an individual suit by relying on

depositions detailing the ways in which other employees were dis-

criminated against by their particular store managers. In contrast,

the employees here, who worked in the same facility, did similar

work, and were paid under the same policy, could have introduced

Mericle’s study in a series of individual suits.

This case presents no occasion for adoption of broad and categorical

rules governing the use of representative and statistical evidence in

class actions. Rather, the ability to use a representative sample to

establish classwide liability will depend on the purpose for which the

sample is being introduced and on the underlying cause of action. In

FLSA actions, inferring the hours an employee has worked from a

study such as Mericle’s has been permitted by the Court so long as

the study is otherwise admissible. Mt. Clemens, supra, at 687.

Pp. 8–15.

(b) Petitioner contends that respondents are required to demon-

strate that uninjured class members will not recover damages here.

That question is not yet fairly presented by this case, because the

damages award has not yet been disbursed and the record does not

indicate how it will be disbursed. Petitioner may raise a challenge to

the allocation method when the case returns to the District Court for

disbursal of the award. Pp. 15–17.

765 F. 3d 791, affirmed and remanded.

KENNEDY, J., delivered the opinion of the Court, in which ROBERTS,

C. J., and GINSBURG, BREYER, SOTOMAYOR, and KAGAN, JJ., joined.

ROBERTS, C. J., filed a concurring opinion, in which ALITO, J., joined as

to Part II. THOMAS, J., filed a dissenting opinion, in which ALITO, J.,

joined.

Cite as: 577 U. S. ____ (2016) 1

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Wash-

ington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES

_________________

No. 14–1146

_________________

TYSON FOODS, INC., PETITIONER v. PEG

BOUAPHAKEO, ET AL., INDIVIDUALLY AND ON BEHALF

OF ALL OTHERS SIMILARLY SITUATED

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE EIGHTH CIRCUIT

[March 22, 2016]

JUSTICE KENNEDY delivered the opinion of the Court.

Following a jury trial, a class of employees recovered

$2.9 million in compensatory damages from their employer

for a violation of the Fair Labor Standards Act of 1938

(FLSA), 52 Stat. 1060, as amended, 29 U. S. C. §201 et seq.

The employees’ primary grievance was that they did not

receive statutorily mandated overtime pay for time spent

donning and doffing protective equipment.

The employer seeks to reverse the judgment. It makes

two arguments. Both relate to whether it was proper to

permit the employees to pursue their claims as a class.

First, the employer argues the class should not have been

certified because the primary method of proving injury

assumed each employee spent the same time donning and

doffing protective gear, even though differences in the

composition of that gear may have meant that, in fact,

employees took different amounts of time to don and doff.

Second, the employer argues certification was improper

because the damages awarded to the class may be distrib-

uted to some persons who did not work any uncompen-

2 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

sated overtime.

The Court of Appeals for the Eighth Circuit concluded

there was no error in the District Court’s decision to cer-

tify and maintain the class. This Court granted certiorari.

576 U. S. ___ (2015).

I

Respondents are employees at petitioner Tyson Foods’

pork processing plant in Storm Lake, Iowa. They work in

the plant’s kill, cut, and retrim departments, where hogs

are slaughtered, trimmed, and prepared for shipment.

Grueling and dangerous, the work requires employees to

wear certain protective gear. The exact composition of the

gear depends on the tasks a worker performs on a given

day.

Until 1998, employees at the plant were paid under a

system called “gang-time.” This compensated them only

for time spent at their workstations, not for the time

required to put on and take off their protective gear. In

response to a federal-court injunction, and a Department

of Labor suit to enforce that injunction, Tyson in 1998

began to pay all its employees for an additional four

minutes a day for what it called “K-code time.” The

4-minute period was the amount of time Tyson estimated

employees needed to don and doff their gear. In 2007,

Tyson stopped paying K-code time uniformly to all em-

ployees. Instead, it compensated some employees for

between four and eight minutes but paid others nothing

beyond their gang-time wages. At no point did Tyson

record the time each employee spent donning and doffing.

Unsatisfied by these changes, respondents filed suit in

the United States District Court for the Northern District

of Iowa, alleging violations of the FLSA. The FLSA re-

quires that a covered employee who works more than 40

hours a week receive compensation for excess time worked

“at a rate not less than one and one-half times the regular

Cite as: 577 U. S. ____ (2016) 3

Opinion of the Court

rate at which he is employed.” 29 U. S. C. §207(a). In

1947, nine years after the FLSA was first enacted, Con-

gress passed the Portal-to-Portal Act, which clarified that

compensable work does not include time spent walking to

and from the employee’s workstation or other “preliminary

or postliminary activities.” §254(d). The FLSA, however,

still requires employers to pay employees for activities

“integral and indispensable” to their regular work, even if

those activities do not occur at the employee’s workstation.

Steiner v. Mitchell, 350 U. S. 247, 249, 255 (1956). The

FLSA also requires an employer to “make, keep, and

preserve . . . records of the persons employed by him and

of the wages, hours, and other conditions and practices of

employment.” §211(c).

In their complaint, respondents alleged that donning

and doffing protective gear were integral and indispensa-

ble to their hazardous work and that petitioner’s policy not

to pay for those activities denied them overtime compensa-

tion required by the FLSA. Respondents also raised a

claim under the Iowa Wage Payment Collection Law. This

statute provides for recovery under state law when an

employer fails to pay its employees “all wages due,” which

includes FLSA-mandated overtime. Iowa Code §91A.3

(2013); cf. Anthony v. State, 632 N. W. 2d 897, 901–902

(Iowa 2001).

Respondents sought certification of their Iowa law

claims as a class action under Rule 23 of the Federal Rules

of Civil Procedure. Rule 23 permits one or more individ-

uals to sue as “representative parties on behalf of all mem-

bers” of a class if certain preconditions are met. Fed. Rule

Civ. Proc. 23(a). Respondents also sought certification of

their federal claims as a “collective action” under 29

U. S. C. §216. Section 216 is a provision of the FLSA that

permits employees to sue on behalf of “themselves and

other employees similarly situated.” §216(b).

Tyson objected to the certification of both classes on the

4 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

same ground. It contended that, because of the variance

in protective gear each employee wore, the employees’

claims were not sufficiently similar to be resolved on a

classwide basis. The District Court rejected that position.

It concluded there were common questions susceptible to

classwide resolution, such as “whether the donning and

doffing of [protective gear] is considered work under the

FLSA, whether such work is integral and [in]dispensable,

and whether any compensable work is de minim[i]s.” 564

F. Supp. 2d 870, 899 (ND Iowa 2008). The District Court

acknowledged that the workers did not all wear the same

protective gear, but found that “when the putative plain-

tiffs are limited to those that are paid via a gang time

system, there are far more factual similarities than dis-

similarities.” Id., at 899–900. As a result, the District

Court certified the following classes:

“All current and former employees of Tyson’s Storm

Lake, Iowa, processing facility who have been em-

ployed at any time from February 7, 2004 [in the case

of the FLSA collective action and February 7, 2005, in

the case of the state-law class action], to the present,

and who are or were paid under a ‘gang time’ compen-

sation system in the Kill, Cut, or Retrim depart-

ments.” Id., at 901.

The only difference in definition between the classes

was the date at which the class period began. The size of

the class certified under Rule 23, however, was larger

than that certified under §216. This is because, while a

class under Rule 23 includes all unnamed members who

fall within the class definition, the “sole consequence of

conditional certification [under §216] is the sending of

court-approved written notice to employees . . . who in

turn become parties to a collective action only by filing

written consent with the court.” Genesis HealthCare Corp.

v. Symczyk, 569 U. S. ___, ___ (2013) (slip op., at 8). A

Cite as: 577 U. S. ____ (2016) 5

Opinion of the Court

total of 444 employees joined the collective action, while

the Rule 23 class contained 3,344 members.

The case proceeded to trial before a jury. The parties

stipulated that the employees were entitled to be paid for

donning and doffing of certain equipment worn to protect

from knife cuts. The jury was left to determine whether

the time spent donning and doffing other protective

equipment was compensable; whether Tyson was required

to pay for donning and doffing during meal breaks; and

the total amount of time spent on work that was not com-

pensated under Tyson’s gang-time system.

Since the employees’ claims relate only to overtime, each

employee had to show he or she worked more than 40

hours a week, inclusive of time spent donning and doffing,

in order to recover. As a result of Tyson’s failure to keep

records of donning and doffing time, however, the employ-

ees were forced to rely on what the parties describe as

“representative evidence.” This evidence included employee

testimony, video recordings of donning and doffing at

the plant, and, most important, a study performed by an

industrial relations expert, Dr. Kenneth Mericle. Mericle

conducted 744 videotaped observations and analyzed how

long various donning and doffing activities took. He then

averaged the time taken in the observations to produce an

estimate of 18 minutes a day for the cut and retrim de-

partments and 21.25 minutes for the kill department.

Although it had not kept records for time spent donning

and doffing, Tyson had information regarding each em-

ployee’s gang-time and K-code time. Using this data, the

employees’ other expert, Dr. Liesl Fox, was able to esti-

mate the amount of uncompensated work each employee

did by adding Mericle’s estimated average donning and

doffing time to the gang-time each employee worked and

then subtracting any K-code time. For example, if an

employee in the kill department had worked 39.125 hours

of gang-time in a 6-day workweek and had been paid an

6 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

hour of K-code time, the estimated number of compensable

hours the employee worked would be: 39.125 (individual

number of gang-time hours worked) + 2.125 (the average

donning and doffing hours for a 6-day week, based on

Mericle’s estimated average of 21.25 minutes a day) – 1

(K-code hours) = 40.25. That would mean the employee

was being undercompensated by a quarter of an hour of

overtime a week, in violation of the FLSA. On the other

hand, if the employee’s records showed only 38 hours of

gang-time and an hour of K-code time, the calculation

would be: 38 + 2.125 – 1 = 39.125. Having worked less than

40 hours, that employee would not be entitled to overtime

pay and would not have proved an FLSA violation.

Using this methodology, Fox stated that 212 employees

did not meet the 40-hour threshold and could not recover.

The remaining class members, Fox maintained, had po-

tentially been undercompensated to some degree.

Respondents proposed to bifurcate proceedings. They

requested that, first, a trial be conducted on the questions

whether time spent in donning and doffing was compensa-

ble work under the FLSA and how long those activities

took to perform on average; and, second, that Fox’s meth-

odology be used to determine which employees suffered an

FLSA violation and how much each was entitled to recover.

Petitioner insisted upon a single proceeding in which

damages would be calculated in the aggregate and by the

jury. The District Court submitted both issues of liability

and damages to the jury.

Petitioner did not move for a hearing regarding the

statistical validity of respondents’ studies under Daubert

v. Merrell Dow Pharmaceuticals, Inc., 509 U. S. 579

(1993), nor did it attempt to discredit the evidence with

testimony from a rebuttal expert. Instead, as it had done

in its opposition to class certification, petitioner argued to

the jury that the varying amounts of time it took employ-

ees to don and doff different protective equipment made

Cite as: 577 U. S. ____ (2016) 7

Opinion of the Court

the lawsuit too speculative for classwide recovery. Peti-

tioner also argued that Mericle’s study overstated the

average donning and doffing time. The jury was in-

structed that nontestifying members of the class could

only recover if the evidence established they “suffered the

same harm as a result of the same unlawful decision or

policy.” App. 471–472.

Fox’s calculations supported an aggregate award of

approximately $6.7 million in unpaid wages. The jury

returned a special verdict finding that time spent in don-

ning and doffing protective gear at the beginning and end

of the day was compensable work but that time during

meal breaks was not. The jury more than halved the

damages recommended by Fox. It awarded the class about

$2.9 million in unpaid wages. That damages award has

not yet been disbursed to the individual employees.

Tyson moved to set aside the jury verdict, arguing,

among other things, that, in light of the variation in don-

ning and doffing time, the classes should not have been

certified. The District Court denied Tyson’s motion, and

the Court of Appeals for the Eighth Circuit affirmed the

judgment and the award.

The Court of Appeals recognized that a verdict for the

employees “require[d] inference” from their representative

proof, but it held that “this inference is allowable under

Anderson v. Mt. Clemens Pottery Co., 328 U. S. 680, 686–

688 (1946).” 765 F. 3d 791, 797 (2014). The Court of

Appeals rejected petitioner’s challenge to the sufficiency of

the evidence for similar reasons, holding that, under the

facts of this case, the jury could have drawn “a ‘reasonable

inference’ of class-wide liability.” Id., at 799 (quoting

Anderson v. Mt. Clemens Pottery Co., 328 U. S. 680, 687

(1946)). Judge Beam dissented, stating that, in his view,

the class should not have been certified.

For the reasons that follow, this Court now affirms.

8 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

II

Petitioner challenges the class certification of the state-

law claims and the certification of the FLSA collective

action. The parties do not dispute that the standard for

certifying a collective action under the FLSA is no more

stringent than the standard for certifying a class under

the Federal Rules of Civil Procedure. This opinion as-

sumes, without deciding, that this is correct. For purposes

of this case then, if certification of respondents’ class

action under the Federal Rules was proper, certification of

the collective action was proper as well.

Furthermore, as noted above, Iowa’s Wage Payment

Collection Law was used in this litigation as a state-law

mechanism for recovery of FLSA-mandated overtime pay.

The parties do not dispute that, in order to prove a viola-

tion of the Iowa statute, the employees had to do no more

than demonstrate a violation of the FLSA. In this opinion,

then, no distinction is made between the requirements for

the class action raising the state-law claims and the collec-

tive action raising the federal claims.

A

Federal Rule of Civil Procedure 23(b)(3) requires that,

before a class is certified under that subsection, a district

court must find that “questions of law or fact common to

class members predominate over any questions affecting

only individual members.” The “predominance inquiry

tests whether proposed classes are sufficiently cohesive to

warrant adjudication by representation.” Amchem Prod-

ucts, Inc. v. Windsor, 521 U. S. 591, 623 (1997). This calls

upon courts to give careful scrutiny to the relation be-

tween common and individual questions in a case. An

individual question is one where “members of a proposed

class will need to present evidence that varies from mem-

ber to member,” while a common question is one where

“the same evidence will suffice for each member to make a

Cite as: 577 U. S. ____ (2016) 9

Opinion of the Court

prima facie showing [or] the issue is susceptible to gener-

alized, class-wide proof.” 2 W. Rubenstein, Newberg on

Class Actions §4:50, pp. 196–197 (5th ed. 2012) (internal

quotation marks omitted). The predominance inquiry

“asks whether the common, aggregation-enabling, issues

in the case are more prevalent or important than the non-

common, aggregation-defeating, individual issues.” Id.,

§4:49, at 195–196. When “one or more of the central is-

sues in the action are common to the class and can be said

to predominate, the action may be considered proper

under Rule 23(b)(3) even though other important matters

will have to be tried separately, such as damages or some

affirmative defenses peculiar to some individual class

members.” 7AA C. Wright, A. Miller, & M. Kane, Federal

Practice and Procedure §1778, pp. 123–124 (3d ed. 2005)

(footnotes omitted).

Here, the parties do not dispute that there are im-

portant questions common to all class members, the most

significant of which is whether time spent donning and

doffing the required protective gear is compensable work

under the FLSA. Cf. IBP, Inc. v. Alvarez, 546 U. S. 21

(2005) (holding that time spent walking between the

locker room and the production area after donning protec-

tive gear is compensable work under the FLSA). To be

entitled to recovery, however, each employee must prove

that the amount of time spent donning and doffing, when

added to his or her regular hours, amounted to more than

40 hours in a given week. Petitioner argues that these

necessarily person-specific inquiries into individual work

time predominate over the common questions raised by

respondents’ claims, making class certification improper.

Respondents counter that these individual inquiries are

unnecessary because it can be assumed each employee

donned and doffed for the same average time observed in

Mericle’s sample. Whether this inference is permissible

becomes the central dispute in this case. Petitioner con-

10 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

tends that Mericle’s study manufactures predominance by

assuming away the very differences that make the case

inappropriate for classwide resolution. Reliance on a

representative sample, petitioner argues, absolves each

employee of the responsibility to prove personal injury,

and thus deprives petitioner of any ability to litigate its

defenses to individual claims.

Calling this unfair, petitioner and various of its amici

maintain that the Court should announce a broad rule

against the use in class actions of what the parties call

representative evidence. A categorical exclusion of that

sort, however, would make little sense. A representative

or statistical sample, like all evidence, is a means to estab-

lish or defend against liability. Its permissibility turns not

on the form a proceeding takes—be it a class or individual

action—but on the degree to which the evidence is reliable

in proving or disproving the elements of the relevant cause

of action. See Fed. Rules Evid. 401, 403, and 702.

It follows that the Court would reach too far were it to

establish general rules governing the use of statistical

evidence, or so-called representative evidence, in all class-

action cases. Evidence of this type is used in various

substantive realms of the law. Brief for Complex Litiga-

tion Law Professors as Amici Curiae 5–9; Brief for Econo-

mists et al. as Amici Curiae 8–10. Whether and when

statistical evidence can be used to establish classwide

liability will depend on the purpose for which the evidence

is being introduced and on “the elements of the underlying

cause of action,” Erica P. John Fund, Inc. v. Halliburton

Co., 563 U. S. 804, 809 (2011).

In many cases, a representative sample is “the only

practicable means to collect and present relevant data”

establishing a defendant’s liability. Manual of Complex

Litigation §11.493, p. 102 (4th ed. 2004). In a case where

representative evidence is relevant in proving a plaintiff ’s

individual claim, that evidence cannot be deemed im-

Cite as: 577 U. S. ____ (2016) 11

Opinion of the Court

proper merely because the claim is brought on behalf of a

class. To so hold would ignore the Rules Enabling Act’s

pellucid instruction that use of the class device cannot

“abridge . . . any substantive right.” 28 U. S. C. §2072(b).

One way for respondents to show, then, that the sample

relied upon here is a permissible method of proving class-

wide liability is by showing that each class member could

have relied on that sample to establish liability if he or she

had brought an individual action. If the sample could

have sustained a reasonable jury finding as to hours

worked in each employee’s individual action, that sample

is a permissible means of establishing the employees’

hours worked in a class action.

This Court’s decision in Anderson v. Mt. Clemens ex-

plains why Mericle’s sample was permissible in the cir-

cumstances of this case. In Mt. Clemens, 7 employees and

their union, seeking to represent over 300 others, brought

a collective action against their employer for failing to

compensate them for time spent walking to and from their

workstations. The variance in walking time among work-

ers was alleged to be upwards of 10 minutes a day, which

is roughly consistent with the variances in donning and

doffing times here. 328 U. S., at 685.

The Court in Mt. Clemens held that when employers

violate their statutory duty to keep proper records, and

employees thereby have no way to establish the time spent

doing uncompensated work, the “remedial nature of [the

FLSA] and the great public policy which it embodies . . .

militate against making” the burden of proving uncom-

pensated work “an impossible hurdle for the employee.”

Id., at 687; see also Hoffmann-La Roche Inc. v. Sperling,

493 U. S. 165, 173 (1989) (“The broad remedial goal of the

statute should be enforced to the full extent of its terms”).

Instead of punishing “the employee by denying him any

recovery on the ground that he is unable to prove the

12 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

precise extent of uncompensated work,” the Court held

“an employee has carried out his burden if he proves that

he has in fact performed work for which he was improper-

ly compensated and if he produces sufficient evidence to

show the amount and extent of that work as a matter of

just and reasonable inference.” 328 U. S., at 687. Under

these circumstances, “[t]he burden then shifts to the em-

ployer to come forward with evidence of the precise

amount of work performed or with evidence to negative

the reasonableness of the inference to be drawn from the

employee’s evidence.” Id., at 687–688.

In this suit, as in Mt. Clemens, respondents sought to

introduce a representative sample to fill an evidentiary

gap created by the employer’s failure to keep adequate

records. If the employees had proceeded with 3,344 indi-

vidual lawsuits, each employee likely would have had to

introduce Mericle’s study to prove the hours he or she

worked. Rather than absolving the employees from prov-

ing individual injury, the representative evidence here

was a permissible means of making that very showing.

Reliance on Mericle’s study did not deprive petitioner of

its ability to litigate individual defenses. Since there were

no alternative means for the employees to establish their

hours worked, petitioner’s primary defense was to show

that Mericle’s study was unrepresentative or inaccurate.

That defense is itself common to the claims made by all

class members. Respondents’ “failure of proof on th[is]

common question” likely would have ended “the litigation

and thus [would not have] cause[d] individual questions

. . . to overwhelm questions common to the class.” Amgen

Inc. v. Connecticut Retirement Plans and Trust Funds, 568

U. S. ___, ___ (2013) (slip op., at 11). When, as here, “the

concern about the proposed class is not that it exhibits

some fatal dissimilarity but, rather, a fatal similarity—[an

alleged] failure of proof as to an element of the plaintiffs’

cause of action—courts should engage that question as a

Cite as: 577 U. S. ____ (2016) 13

Opinion of the Court

matter of summary judgment, not class certification.”

Nagareda, Class Certification in the Age of Aggregate

Proof, 84 N. Y. U. L. Rev. 97, 107 (2009).

Petitioner’s reliance on Wal-Mart Stores, Inc. v. Dukes,

564 U. S. 338 (2011), is misplaced. Wal-Mart does not

stand for the broad proposition that a representative

sample is an impermissible means of establishing class-

wide liability.

Wal-Mart involved a nationwide Title VII class of over

11∕2 million employees. In reversing class certification, this

Court did not reach Rule 23(b)(3)’s predominance prong,

holding instead that the class failed to meet even Rule

23(a)’s more basic requirement that class members share a

common question of fact or law. The plaintiffs in Wal-

Mart did not provide significant proof of a common policy

of discrimination to which each employee was subject.

“The only corporate policy that the plaintiffs’ evidence

convincingly establishe[d was] Wal-Mart’s ‘policy’ of allow-

ing discretion by local supervisors over employment mat-

ters”; and even then, the plaintiffs could not identify “a

common mode of exercising discretion that pervade[d] the

entire company.” Id., at 355–356 (emphasis deleted).

The plaintiffs in Wal-Mart proposed to use representa-

tive evidence as a means of overcoming this absence of a

common policy. Under their proposed methodology, a

“sample set of the class members would be selected, as to

whom liability for sex discrimination and the backpay

owing as a result would be determined in depositions

supervised by a master.” Id., at 367. The aggregate dam-

ages award was to be derived by taking the “percentage of

claims determined to be valid” from this sample and ap-

plying it to the rest of the class, and then multiplying the

“number of (presumptively) valid claims” by “the average

backpay award in the sample set.” Ibid. The Court held

that this “Trial By Formula” was contrary to the Rules

Enabling Act because it “ ‘enlarge[d]’ ” the class members’

14 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

“ ‘substantive right[s]’ ” and deprived defendants of their

right to litigate statutory defenses to individual claims.

Ibid.

The Court’s holding in the instant case is in accord with

Wal-Mart. The underlying question in Wal-Mart, as here,

was whether the sample at issue could have been used to

establish liability in an individual action. Since the Court

held that the employees were not similarly situated, none

of them could have prevailed in an individual suit by

relying on depositions detailing the ways in which other

employees were discriminated against by their particular

store managers. By extension, if the employees had

brought 11∕2 million individual suits, there would be little

or no role for representative evidence. Permitting the use

of that sample in a class action, therefore, would have

violated the Rules Enabling Act by giving plaintiffs and

defendants different rights in a class proceeding than they

could have asserted in an individual action.

In contrast, the study here could have been sufficient to

sustain a jury finding as to hours worked if it were intro-

duced in each employee’s individual action. While the

experiences of the employees in Wal-Mart bore little rela-

tionship to one another, in this case each employee worked

in the same facility, did similar work, and was paid under

the same policy. As Mt. Clemens confirms, under these

circumstances the experiences of a subset of employees

can be probative as to the experiences of all of them.

This is not to say that all inferences drawn from repre-

sentative evidence in an FLSA case are “just and reason-

able.” Mt. Clemens, 328 U. S., at 687. Representative

evidence that is statistically inadequate or based on im-

plausible assumptions could not lead to a fair or accurate

estimate of the uncompensated hours an employee has

worked. Petitioner, however, did not raise a challenge to

respondents’ experts’ methodology under Daubert; and, as

a result, there is no basis in the record to conclude it was

Cite as: 577 U. S. ____ (2016) 15

Opinion of the Court

legal error to admit that evidence.

Once a district court finds evidence to be admissible, its

persuasiveness is, in general, a matter for the jury. Rea-

sonable minds may differ as to whether the average time

Mericle calculated is probative as to the time actually

worked by each employee. Resolving that question, how-

ever, is the near-exclusive province of the jury. The Dis-

trict Court could have denied class certification on this

ground only if it concluded that no reasonable juror could

have believed that the employees spent roughly equal time

donning and doffing. Cf. Anderson v. Liberty Lobby, Inc.,

477 U. S. 242, 250–252 (1986). The District Court made

no such finding, and the record here provides no basis for

this Court to second-guess that conclusion.

The Court reiterates that, while petitioner, respondents,

or their respective amici may urge adoption of broad and

categorical rules governing the use of representative and

statistical evidence in class actions, this case provides no

occasion to do so. Whether a representative sample may

be used to establish classwide liability will depend on the

purpose for which the sample is being introduced and on

the underlying cause of action. In FLSA actions, inferring

the hours an employee has worked from a study such as

Mericle’s has been permitted by the Court so long as the

study is otherwise admissible. Mt. Clemens, supra, at 687;

see also Fed. Rules Evid. 402 and 702. The fairness and

utility of statistical methods in contexts other than those

presented here will depend on facts and circumstances

particular to those cases.

B

In its petition for certiorari petitioner framed its second

question presented as whether a class may be certified if it

contains “members who were not injured and have no

legal right to any damages.” Pet. for Cert. i. In its merits

brief, however, petitioner reframes its argument. It now

16 TYSON FOODS, INC. v. BOUAPHAKEO

Opinion of the Court

concedes that “[t]he fact that federal courts lack authority

to compensate persons who cannot prove injury does not

mean that a class action (or collective action) can never be

certified in the absence of proof that all class members

were injured.” Brief for Petitioner 49. In light of petition-

er’s abandonment of its argument from the petition, the

Court need not, and does not, address it.

Petitioner’s new argument is that, “where class plain-

tiffs cannot offer” proof that all class members are injured,

“they must demonstrate instead that there is some mech-

anism to identify the uninjured class members prior to

judgment and ensure that uninjured members (1) do not

contribute to the size of any damage award and (2) cannot

recover such damages.” Ibid. Petitioner contends that

respondents have not demonstrated any mechanism for

ensuring that uninjured class members do not recover

damages here.

Petitioner’s new argument is predicated on the assump-

tion that the damages award cannot be apportioned so

that only those class members who suffered an FLSA

violation recover. According to petitioner, because Fox’s

mechanism for determining who had worked over 40 hours

depended on Mericle’s estimate of donning and doffing

time, and because the jury must have rejected Mericle’s

estimate when it reduced the damages award by more

than half, it will not be possible to know which workers

are entitled to share in the award.

As petitioner and its amici stress, the question whether

uninjured class members may recover is one of great

importance. See, e.g., Brief for Consumer Data Industry

Association as Amicus Curiae. It is not, however, a ques-

tion yet fairly presented by this case, because the damages

award has not yet been disbursed, nor does the record

indicate how it will be disbursed.

Respondents allege there remain ways of distributing

the award to only those individuals who worked more than

Cite as: 577 U. S. ____ (2016) 17

Opinion of the Court

40 hours. For example, by working backwards from the

damages award, and assuming each employee donned and

doffed for an identical amount of time (an assumption that

follows from the jury’s finding that the employees suffered

equivalent harm under the policy), it may be possible to

calculate the average donning and doffing time the jury

necessarily must have found, and then apply this figure to

each employee’s known gang-time hours to determine

which employees worked more than 40 hours.

Whether that or some other methodology will be suc-

cessful in identifying uninjured class members is a ques-

tion that, on this record, is premature. Petitioner may

raise a challenge to the proposed method of allocation

when the case returns to the District Court for disbursal of

the award.

Finally, it bears emphasis that this problem appears to

be one of petitioner’s own making. Respondents proposed

bifurcating between the liability and damages phases of

this proceeding for the precise reason that it may be diffi-

cult to remove uninjured individuals from the class after

an award is rendered. It was petitioner who argued

against that option and now seeks to profit from the diffi-

culty it caused. Whether, in light of the foregoing, any

error should be deemed invited, is a question for the Dis-

trict Court to address in the first instance.

* * *

The judgment of the Court of Appeals for the Eighth

Circuit is affirmed, and the case is remanded for further

proceedings consistent with this opinion.

It is so ordered.

Cite as: 577 U. S. ____ (2016) 1

ROBERTS, C. J., concurring

SUPREME COURT OF THE UNITED STATES

_________________

No. 14–1146

_________________

TYSON FOODS, INC., PETITIONER v. PEG

BOUAPHAKEO, ET AL., INDIVIDUALLY AND ON BEHALF

OF ALL OTHERS SIMILARLY SITUATED

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE EIGHTH CIRCUIT

[March 22, 2016]

CHIEF JUSTICE ROBERTS, with whom JUSTICE ALITO

joins as to Part II, concurring.

Petitioner Tyson Foods presents two primary argu-

ments. First, it claims that class certification was im-

proper because each individual plaintiff spent different

amounts of time donning and doffing protective gear.

Therefore, according to Tyson, whether and to what extent

it owed damages to each individual employee for uncom-

pensated overtime was not a question capable of resolu-

tion on a class-wide basis. Second, Tyson argues that the

verdict cannot stand because, while no one disputes that

the class as certified contains hundreds of uninjured em-

ployees, the plaintiffs have not come up with any way to

ensure that those employees do not recover damages from

the jury’s lump-sum award.

The Court rejects the first argument and leaves the

second for initial resolution by the lower courts. I join the

Court’s opinion in full. I write separately to explain my

understanding of the Court’s resolution of the case and to

express my concern that the District Court may not be

able to fashion a method for awarding damages only to

those class members who suffered an actual injury.

2 TYSON FOODS, INC. v. BOUAPHAKEO

ROBERTS, C. J., concurring

I

A class may be certified under Federal Rule of Civil

Procedure 23(b)(3) only if “questions of law or fact common

to class members predominate over any questions affect-

ing only individual members.” A common question is one

in which “the issue is susceptible to generalized, class-

wide proof.” Ante, at 9 (quoting 2 W. Rubenstein, Newberg

on Class Actions §4:50, pp. 196–197 (5th ed. 2012)) (inter-

nal quotation marks omitted).

To prove liability and damages, respondents had to

establish the amount of compensable (but uncompensated)

donning and doffing time for each individual plaintiff. The

Court properly concludes that despite the differences in

donning and doffing time for individual class members,

respondents could adequately prove the amount of time for

each individual through generalized, class-wide proof.

That proof was Dr. Mericle’s representative study. As the

Court observes, “each class-member could have relied on

that [study] to establish liability if he or she had brought

an individual action.” Ante, at 11. And when representa-

tive evidence would suffice to prove a plaintiff ’s individual

claim, that evidence cannot be deemed improper merely

because the claim is brought as part of a class action. See

ante, at 10–11.

I agree with JUSTICE THOMAS that our decision in An-

derson v. Mt. Clemens Pottery Co., 328 U. S. 680 (1946),

does not provide a “special, relaxed rule authorizing plain-

tiffs to use otherwise inadequate representative evidence

in FLSA-based cases.” Post, at 7 (dissenting opinion). But

I do not read the Court’s opinion to be inconsistent with

that conclusion. Rather, I take the Court to conclude that

Dr. Mericle’s study constituted sufficient proof from which

the jury could find “the amount and extent of [each indi-

vidual respondent’s] work as a matter of just and reasona-

ble inference”—the same standard of proof that would

apply in any case. Ante, at 12 (internal quotation marks

Cite as: 577 U. S. ____ (2016) 3

ROBERTS, C. J., concurring

omitted). It is with that understanding that I join the

opinion of the Court.

II

As for Tyson’s second argument, it is undisputed that

hundreds of class members suffered no injury in this case.

See Brief for Respondents 52–53; Tr. of Oral Arg. 30. The

question is: which ones? The only way to know is to figure

out how much donning and doffing time the jury found

Tyson owed the workers in each department. But the jury

returned a lump-sum verdict of $2.9 million on a class-

wide basis, without specifying any particular amount of

donning and doffing time used to calculate that number.

If we knew that the jury had accepted the plaintiffs’ pro-

posed average donning and doffing times in calculating

the verdict, we could easily overcome this problem. But

we know the jury did no such thing. And with no way to

reverse engineer the verdict to determine how much don-

ning and doffing time the jury found Tyson owed workers

in each department, we do not know which plaintiffs the

jury found to be injured (or not).

Tyson contends that unless the District Court can fash-

ion a means of identifying those class members not enti-

tled to damages, it must throw out the jury’s verdict and

decertify the class. I agree with the Court’s decision to

leave that issue to be addressed in the first instance by the

District Court. But I am not convinced that the District

Court will be able to devise a means of distributing the

aggregate award only to injured class members.

As the Court explains, each plaintiff in this case suf-

fered actual harm only if he: (1) was not compensated for

at least some compensable donning and doffing time; and

(2) worked more than 40 hours in a workweek, including

any compensable donning and doffing time. See ante, at

16–17. In other words, it is not enough that a plaintiff

was uncompensated for compensable donning and doffing

4 TYSON FOODS, INC. v. BOUAPHAKEO

ROBERTS, C. J., concurring

time; unless that plaintiff also worked more than 40 hours

in a week (including compensable donning and doffing

time), he is owed no overtime pay and therefore suffered

no injury.

If the jury credited Dr. Mericle’s averages—18 minutes

per day of donning and doffing time for employees in the

fabrication (cut and retrim) departments, 21.25 for em-

ployees in the kill department—the District Court could

have assumed that the jury found that each plaintiff from

those departments donned and doffed the average

amounts of time and used those averages to determine

which plaintiffs had worked more than 40 hours (and

awarded damages on that understanding).

The problem is that the jury obviously did not credit Dr.

Mericle’s averages. According to Dr. Fox, another of the

plaintiffs’ experts, those averages would have resulted in a

$6.7 million verdict across the 3,344 member class. Ante,

at 7. The jury, however, awarded the plaintiffs only $2.9

million.

How, then, did the jury arrive at that $2.9 million fig-

ure? The jury might have determined that Dr. Mericle’s

average was correct for the kill department, but overstated

for the fabrication departments. Or vice versa. Or the

jury might have found that Dr. Mericle’s averages over-

stated the donning and doffing time in all departments, by

varying degrees. Any of those conclusions would have

been permissible on these facts, and any of those options

would have reduced the jury verdict from the $6.7 million

proposed by Dr. Fox. But in arriving at the $2.9 million

verdict, we have no way of knowing how much donning

and doffing time the jury actually found to have occurred

in the kill and fabrication departments, respectively.

And there’s the rub. We know that the jury must have

found at least one of Dr. Mericle’s two averages to be too

high. And we know, as Dr. Fox testified, that if Dr. Mer-

icle’s averages were even slightly too high, hundreds of

Cite as: 577 U. S. ____ (2016) 5

ROBERTS, C. J., concurring

class members would fall short of the 40-hour workweek

threshold that would entitle them to damages. See post,

at 5–6. But because we do not know how much donning

and doffing time the jury found to have occurred in each

department, we have no way of knowing which plaintiffs

failed to cross that 40-hour threshold.

To illustrate: Take a fabrication employee and a kill

employee, each of whom worked a 39-hour workweek

before counting any compensable donning and doffing

time. If the jury credited Dr. Mericle’s kill department

average but discounted his fabrication average to below

one hour per week, the jury would have found that the kill

employee was injured, while the fabrication employee was

not. But the jury also might have done the exact opposite.

We just don’t know—and so we have no way to determine

which plaintiffs the jury concluded were injured.

The plaintiffs believe they can surmount this obstacle.

As the Court explains, they propose to work backward

from the damages award by assuming that each employee

donned and doffed for an identical amount of time. Ante,

at 16–17. That won’t work, however, because there is no

indication that the jury made the same assumption.

Indeed, the most reasonable guess is that the jury did not

find that employees in different departments donned and

doffed for identical amounts of time. After all, the plain-

tiffs’ own expert indicated that employees in different

departments donned and doffed for different amounts of

time.

Given this difficulty, it remains to be seen whether the

jury verdict can stand. The Court observes in dicta that

the problem of distributing the damages award “appears

to be one of petitioner’s own making.” Ante, at 17. Per-

haps. But Tyson’s insistence on a lump-sum jury award

cannot overcome the limitations placed on the federal

courts by the Constitution. Article III does not give fed-

eral courts the power to order relief to any uninjured plain-

6 TYSON FOODS, INC. v. BOUAPHAKEO

ROBERTS, C. J., concurring

tiff, class action or not. The Judiciary’s role is limited “to

provid[ing] relief to claimants, in individual or class ac-

tions, who have suffered, or will imminently suffer, actual

harm.” Lewis v. Casey, 518 U. S. 343, 349 (1996). There-

fore, if there is no way to ensure that the jury’s damages

award goes only to injured class members, that award

cannot stand. This issue should be considered by the

District Court in the first instance. As the Court properly

concludes, the problem is not presently ripe for our review.

Cite as: 577 U. S. ____ (2016) 1

THOMAS, J., dissenting

SUPREME COURT OF THE UNITED STATES

_________________

No. 14–1146

_________________

TYSON FOODS, INC., PETITIONER v. PEG

BOUAPHAKEO, ET AL., INDIVIDUALLY AND ON BEHALF

OF ALL OTHERS SIMILARLY SITUATED

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE EIGHTH CIRCUIT

[March 22, 2016]

JUSTICE THOMAS, with whom JUSTICE ALITO joins,

dissenting.

Our precedents generally prohibit plaintiffs from main-

taining a class action when an important element of liabil-

ity depends on facts that vary among individual class

members. This case concerns whether and when class-

action plaintiffs can overcome that general rule by using

representative evidence as common proof of an otherwise

individualized issue. Our precedents resolve that ques-

tion: Before class-action plaintiffs can use representative

evidence in this way, district courts must undertake a

rigorous analysis to ensure that such evidence is suffi-

ciently probative of the individual issue to make it suscep-

tible to classwide proof. The District Court did not satisfy

that obligation here, and its failure to do so prejudiced

defendant Tyson Foods at trial. The majority reaches a

contrary conclusion by redefining class-action require-

ments and devising an unsound special evidentiary rule

for cases under the Fair Labor Standards Act of 1938

(FLSA), 29 U. S. C. §201 et seq. I respectfully dissent.

I

“The class action is an exception to the usual rule that

litigation is conducted by and on behalf of the individual

2 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

named parties only.” Comcast Corp. v. Behrend, 569 U. S.

___, ___ (2013) (slip op., at 5) (internal quotation marks

omitted). Plaintiffs thus “must affirmatively demonstrate

[their] compliance” with Rule 23. Wal-Mart Stores, Inc. v.

Dukes, 564 U. S. 338, 350 (2011). Where, as here, a puta-

tive class seeks money damages, plaintiffs also must

satisfy the “demanding” standard of predominance, Com-

cast, supra, at ___ (slip op., at 6), by proving that “ques-

tions of law or fact common to class members predominate

over any questions affecting only individual members.”

Fed. Rule Civ. Proc. 23(b)(3).

District courts must also ensure continued compliance

with Rule 23 throughout the case. When a district court

erroneously certifies a class, then holds a trial, reversal is

required when the record shows that improper certifica-

tion prejudiced the defendant. And an incorrect class

certification decision almost inevitably prejudices the

defendant. When a district court allows class plaintiffs to

prove an individualized issue with classwide evidence, the

court relieves them of their burden to prove each element

of their claim for each class member and impedes the

defendant’s efforts to mount an effective defense.

Here, the District Court misconstrued the elements of

the plaintiffs’ claims. And it failed to recognize that one

critical element of those claims raised an individual issue

that would predominate over any common issues. The

court therefore did not ask whether that individual issue

was susceptible to common proof. That error, at the class

certification stage, then prejudiced Tyson at trial. It was

only at trial that the plaintiffs introduced the critical

evidence at issue in this case. They introduced, as repre-

sentative of the class, a study by the plaintiffs’ expert, Dr.

Kenneth Mericle. The District Court still declined to

consider whether this evidence was appropriate common

proof — even though the study showed wide variations

Cite as: 577 U. S. ____ (2016) 3

THOMAS, J., dissenting

among class members on an important individual issue.

These errors prejudiced Tyson and warrant reversal.

A

The District Court erred at the class certification stage

by holding that the plaintiffs satisfied Rule 23’s predomi-

nance requirement. The plaintiffs alleged that Tyson

failed to adequately pay workers overtime for donning and

doffing protective gear, in violation of the Iowa Wage

Payment Collection Law, Iowa Code §91A.3 (2013). This

Iowa law mirrors the FLSA. 1 An employer violates these

laws if it employs someone “for a workweek longer than

forty hours” and fails to adequately compensate him for

the overtime. 29 U. S. C. §207(a)(1). Here, the plaintiffs

could establish Tyson’s liability to all class members only

if: (1) the donning and doffing at issue is compensable

work; (2) all employees worked over 40 hours, including

donning and doffing time; and (3) Tyson failed to compen-

sate each employee for all overtime.

The District Court should have begun its predominance

inquiry by determining which elements of the plaintiffs’

claims present common or individual issues, and assessed

whether individual issues would overwhelm common ones.

See Halliburton Co. v. Erica P. John Fund, Inc., 573 U. S.

___, ___ (2014) (slip op., at 14–15); Erica P. John Fund,

Inc. v. Halliburton Co., 563 U. S. 804, 809 (2011). The

plaintiffs’ claims here had one element that was clearly

individualized: whether each employee worked over 40

hours without receiving full overtime pay. The amount of

time that employees spent on donning and doffing varied

by person because individuals take different amounts of

time to don and doff the same gear, and their gear varied.

——————

1 The plaintiffs also brought a collective action under the FLSA. Be-

cause the jury verdict combined the two actions, deficiencies in the

class action require reversal of the entire judgment.

4 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

This issue was critical to determining Tyson’s liability

because some employees would not have worked over 40

hours per week without counting time spent on donning

and doffing. The critical issue for class certification thus

was whether the individualized nature of employees’

donning and doffing times defeated predominance.

The District Court, however, certified a 3,344–member

class without acknowledging the significance of this indi-

vidual issue, let alone addressing whether it was suscepti-

ble to common proof. The court acknowledged that

“[i]ndividual questions may exist” and that Tyson was

objecting to being “forced to defend against un common

evidence” because the plaintiffs had no common evidence

establishing what gear all employees wore “or how long

[they] spend donning and doffing their [gear].” 564

F. Supp. 2d 870, 900, 909 (ND Iowa 2008). But, in the

District Court’s view, common issues predominated be-

cause the plaintiffs could establish classwide liability just

by showing that Tyson was not paying any employee for

the time it took to don or doff basic gear. Id., at 909; see

id., at 900, 904, 905 (similar).

The District Court thus did not give proper considera-

tion to the significance of variable donning and doffing

times. Establishing an FLSA violation across the entire

class was impossible without evidence that each employee

would have worked over 40 hours per week if donning and

doffing time were included. But the District Court did not

fully appreciate that this was a critical individual issue

that defined Tyson’s liability, and it did not analyze, in

any way, whether this issue was susceptible to common

proof. As a result, the District Court erred when it certi-

fied the class.

B

It was only later at trial that the plaintiffs introduced

the critical evidence that they claimed could establish all

Cite as: 577 U. S. ____ (2016) 5

THOMAS, J., dissenting

employees’ donning and doffing times on a classwide basis.

This evidence came from the plaintiffs’ expert, Dr. Mericle,

who studied how long certain Tyson employees took to don

and doff various gear. This was the “most important”

evidence at trial. Ante, at 5. Without it, the plaintiffs

almost certainly could not have obtained a classwide

verdict. But rather than showing that employees’ donning

and doffing times were susceptible to classwide proof,

Mericle’s evidence showed that employees’ donning and

doffing times varied materially. Mericle’s evidence thus

confirmed the inappropriateness of class treatment.

Mericle used about 53 employees per donning- or doffing-

related activity to extrapolate averages for the 3,344–

person class. By averaging the times that sample employ-

ees spent per activity, Mericle estimated that all cut or

retrim department employees spent 18 minutes per day on

uncompensated activities (including donning and doffing),

while kill department employees averaged 21.25 minutes.

Mericle’s data, however, revealed material variances in

the amount of time that individual employees spent on the

same activities. Cut and retrim employees took between

0.583 minutes and over 10 minutes to don preshift equip-

ment at their lockers. Postshift doffing took one employee

less than two minutes, and another over nine minutes.

Kill department employees had similar variances. No two

employees performed the same activity in the same

amount of time, and Mericle observed “a lot of variation

within the activity.” App. 387.

The plaintiffs’ trial evidence also showed that variances

in the amount of time that employees spent on donning

and doffing activities significantly affected the number of

class members who could assert overtime claims. The

plaintiffs’ other expert, Dr. Liesl Fox, added Mericle’s

average times to individual employees’ timesheets to

determine which class members had overtime claims. She

discovered that 212 of the 3,344 class members had no

6 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

claims at all because they had not worked over 40 hours

per week. If Mericle’s averages even slightly overesti-

mated average donning and doffing times, another 282 class

members would have no overtime claims. If average

donning or doffing times dropped from 18–21 minutes to

15 minutes, Fox stated, another 110 employees had no

overtime claims. According to Fox, incremental changes to

donning and doffing times mattered so much that her

estimated damages figure ($6.6 million) would be mean-

ingless if the jury discounted Mericle’s data at all. Yet the

jury ultimately rejected that damages figure—seemingly

disagreeing that Mericle’s average times reflected the

amount of time that every class member spent donning

and doffing.

Because the District Court did not evaluate Mericle’s

and Fox’s evidence in its initial class certification decision,

it should have revisited certification when faced with this

evidence at trial. It declined to do so even after Tyson

objected to using this evidence to establish the amount of

time all class members spent donning and doffing. See

2011 WL 3793962 (ND Iowa, Aug. 25, 2011) (rejecting

decertification motion); 2012 WL 4471119 (ND Iowa, Sept.

26, 2012) (summarily denying post-trial decertification).

The court thus never made findings or analyzed whether,

under Rule 23(b)(3), Mericle’s study could be used as

common proof of an individual issue that would otherwise

preclude class treatment.

The District Court’s jury instructions did not cure this

deficiency. No instruction could remedy a court’s failure to

address why an individual issue was susceptible to com-

mon proof. In any event, the court instructed the jury that

“expert testimony”—like Mericle’s—should get “as much

weight as you think it deserves.” App. 471. The court also

let the jury rely on representative evidence to establish

each class member’s claim even if the jury believed that

employees’ donning and doffing times varied considerably.

Cite as: 577 U. S. ____ (2016) 7

THOMAS, J., dissenting

See ibid.

In sum, the plaintiffs at no time had to justify whether

the variability among class members here was too much

for representative evidence to fill the gap with common

proof. Nor did the District Court address whether Mer-

icle’s study—which showed significant variability in how

much time employees spent on donning and doffing—was

permissible common proof. These errors created an unac-

ceptable risk that Tyson would be held liable to a large

class without adequate proof that each individual class

member was owed overtime. Before defendants can be

forced to defend against a class action, courts must be sure

that Rule 23’s criteria are met. The District Court’s fail-

ure to do so warrants reversal.

II

The majority reaches a contrary result by erring in

three significant ways. First, the majority alters the

predominance inquiry so that important individual issues

are less likely to defeat class certification. Next, the ma-

jority creates a special, relaxed rule authorizing plaintiffs

to use otherwise inadequate representative evidence in

FLSA-based cases by misreading Anderson v. Mt. Clemens

Pottery Co., 328 U. S. 680 (1946). Finally, the majority

points to Tyson’s litigation strategy and purported differ-

ences from prior Rule 23 precedents. None of these justifi-

cations withstands scrutiny.

A

The majority begins by redefining the predominance

standard. According to the majority, if some “ ‘central

issues’ ” present common questions, “ ‘the action may be

considered proper under Rule 23(b)(3) even though other

important matters will have to be tried separately, such as

damages or some affirmative defenses peculiar to some

individual class members.’ ” Ante, at 9 (quoting, 7AA C.

8 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

Wright, A. Miller, & M. Kane, Federal Practice & Proce-

dure §1778, pp. 123–124 (3d ed. 2005; footnotes omitted)).

We recently—and correctly—held the opposite. In

Comcast, we deemed the lack of a common methodology

for proving damages fatal to predominance because

“[q]uestions of individual damage calculations will inevi-

tably overwhelm questions common to the class.” 569

U. S., at ___ (slip op., at 7). 2 If, as the majority states, this

case presents “no occasion” to announce “broad and cate-

gorical rules governing the use of representative and

statistical evidence in class actions,” ante, at 15, it should

most certainly not present an occasion to transform basic

aspects of the predominance inquiry.

B

The majority further errs in concluding that the repre-

sentative evidence here showed that class members’

claims were susceptible to common proof. See ante, at 8–

15. As the majority observes, representative evidence can

be used to prove an individual issue on a classwide basis if

each class member, in an individual action, could rely on

that evidence to prove his individual claim. Ante, at 11.

But that premise should doom the plaintiffs’ case. Even

testifying class members would seem unable to use Mer-

icle’s averages. For instance, Mericle’s study estimated

that kill department employees took an average 6.4

minutes to don equipment at their lockers before their

——————

2 The

majority relies on the same treatise citations that the Comcast

dissent invoked to argue that individualized damages calculations

should never defeat predominance. 569 U. S., at ___–___ (slip op., at

3–4) (opinion of BREYER, J.). Since then, these treatises have acknowl-

edged the tension between their views of predominance and Comcast.

See 7AA C. Wright, A. Miller, & M. Kane, Federal Practice and Proce-

dure, §1778, p. 37 (3d ed. Supp. 2015); 2 W. Rubenstein, Newberg on

Class Actions §4:54, p. 21 (5th ed. Supp. June 2015).

Cite as: 577 U. S. ____ (2016) 9

THOMAS, J., dissenting

shift—but employee Donald Brown testified that this

activity took him around 2 minutes. Others also testified

to donning and doffing times that diverged markedly from

Mericle’s estimates. So Mericle’s study could not sustain a

jury verdict in favor of these plaintiffs, had they brought

individual suits.

According to the majority, this disparity between aver-

age times and individual times poses no problem because

Anderson v. Mt. Clemens Pottery Co., 328 U. S. 680, allows

plaintiffs to use such representative evidence as common

proof. See ante, at 11–14. In the majority’s view, Mt.

Clemens established that (1) if the employer did not record

the time that employees spent on compensable work,

employees can use representative evidence to establish the

employer’s liability, ante, at 11–12; and (2) employees can

use “the experiences of a subset of employees” to establish

“the experiences of all of them” if “each employee worked

in the same facility, did similar work[,] and was paid

under the same policy,” ante, at 14.

The majority’s reliance on Mt. Clemens is questionable

given that decision’s shaky foundations. Seventy years

ago, Mt. Clemens construed the FLSA broadly to vindicate

the Court’s understanding of the FLSA’s “remedial” pur-

poses. 328 U. S., at 687. Within a year, Congress rejected

that interpretation. Citing the “emergency” this Court

had created by spurring “excessive and needless litiga-

tion,” Congress repudiated this Court’s understanding of

what the FLSA meant by “work” and the “workweek” and

limited employees’ ability to sue collectively. 29 U. S. C.

§§251(a)–(b); see Integrity Staffing Solutions, Inc. v. Busk,

574 U. S. ___, ___ (2014) (slip op., at 3–5) (noting repudia-

tion in the Portal-to-Portal Act of 1947); Hoffmann-La

Roche Inc. v. Sperling, 493 U. S. 165, 173 (1989) (noting

repudiation of representative actions ). Since then, this

10 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

Court has decided many FLSA cases, but has never relied

on Mt. Clemens to do so. 3

Putting these concerns aside, the majority today goes

beyond what Mt. Clemens held. First, Mt. Clemens does

not hold that employees can use representative evidence

in FLSA cases to prove an otherwise uncertain element of

liability. Mt. Clemens involved an employer’s alleged

failure to pay employees for time they spent walking to

and from their work spaces and on preshift preparatory

activities. See 328 U. S., at 684–685. The Court held that

the FLSA required employers to compensate employees for

those activities. Id., at 690–692 (overruled by 29 U. S. C.

§§252, 254). The employer was thus presumptively liable

to all employees because they all claimed to work 40 hours

per week. See Record in Mt. Clemens, O.T. 1945, No. 342

(Record), pp. 10–11 (complaint). All additional uncompen-

sated work was necessarily unpaid overtime. That ex-

plains why the Court “assum[ed] that the employee has

proved that he has performed work and has not been paid

in accordance with the statute.” 328 U. S., at 688.

Mt. Clemens also rejected the notion that employees who

had already established the employer’s liability had to

prove damages using precise, employee-specific records.

Id., at 687. Rather, if the employer failed to keep records

but its liability was certain, employees could use evidence

that “show[ s ] the amount and extent of that work as a

——————

3 THE CHIEF JUSTICE believes that the majority does not actually de-

pend upon Mt. Clemens as a special evidentiary rule, and instead

applies “the same standard of proof that would apply in any case.”

Ante, at 2. That interpretation is difficult to credit given that the

majority never explains why Dr. Mericle’s representative evidence

could have sustained a jury finding in favor of any individual employee

in an individual case, and instead devotes several paragraphs to the

proposition that “[t]his Court’s decision in [Mt. Clemens] explains why

Dr. Mericle’s sample was permissible in the circumstances of this case.”

Ante, at 11; see id., at 11-12.

Cite as: 577 U. S. ____ (2016) 11

THOMAS, J., dissenting

matter of just and reasonable inference.” Ibid. The Court,

however, limited this holding to instances where the em-

ployer’s FLSA violation was “certain,” as in Mt. Clemens

itself. Id., at 688; see ibid. (inference permissible “as to

the extent of the damages”). Mt. Clemens does not justify

the use of representative evidence in this case, where

Tyson’s liability to many class members was uncertain.

Second, the majority misreads Mt. Clemens as “con-

firm[ing]” that when employees “worked in the same

facility, did similar work and w[ere] paid under the same

policy,” representative evidence can prove all of their

claims. Ante, at 14. Mt. Clemens said nothing about

whether or why the employees there shared sufficient

similarities for their claims to be susceptible to common

proof. The Mt. Clemens plaintiffs were the local union and

seven employees. See 328 U. S., at 684. They brought a

representative action, a type of collective action that al-

lowed employees to designate a union to pursue their

claims for them. See §16(b), 52 Stat. 1069; Record 7 (com-

plaint). Some 300 employees did so. See Mt. Clemens

Pottery Co. v. Anderson, 149 F. 2d, 461 (CA6 1945); Record

33–41. The District Court did not make findings about

what made these employees similar, instead reasoning

that the FLSA’s broad objectives supported a liberal ap-

proach to allowing class suits. Record 29–32 (June 13,

1941, order). This Court also said nothing about whether

the employees suffered the same harm in the same man-

ner; that issue was not before it. In Mt. Clemens’ after-

math, however, Congress eliminated representative ac-

tions, like the one in Mt. Clemens, that required too few

similarities among plaintiffs and allowed plaintiffs “not

themselves possessing claims” to sue. Hoffman-La Roche,

supra, at 173. Mt. Clemens thus offers no guidance

about what degree of similarity among employees suffices

for representative evidence to establish all employees’

experiences.

12 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

In any event, Mt. Clemens did not accept that the repre-

sentative evidence there would be probative even were the

employees sufficiently similar. All Mt. Clemens decided

was that the lack of precise data about the amount of time

each employee worked was not fatal to their case. 328

U. S., at 686–687. The Court then remanded the case,

leaving the lower courts to “draw whatever reasonable

inferences can be drawn from the employees’ evidence,” if

any. Id., at 693–694. 4 Mt. Clemens therefore does not

support the majority’s conclusion that representative

evidence can prove thousands of employees’ FLSA claims

if they share a facility, job functions, and pay policies. See

ante, at 14.

By focusing on similarities irrelevant to whether em-

ployees spend variable times on the task for which they

are allegedly undercompensated, the majority would allow

representative evidence to establish classwide liability

even where much of the class might not have overtime

claims at all. Whether employees work in one plant or

many, have similar job functions, or are paid at the same

rate has nothing to do with how fast they walk, don, or

doff—the key variables here for FLSA liability.

The majority suggests that Mt. Clemens’ evidentiary

rule is limited to cases where the employer breaches its

obligation to keep records of employees’ compensable

work. See ante, at 11–12. But that limitation is illusory.

FLSA cases often involve allegations that a particular

activity is uncompensated work. Just last Term, we re-

——————

4 If anything, Mt. Clemens suggests that the representative evidence

here is impermissible. The Court affirmed that the District Court’s

proposed “formula of compensation,” calculated based on estimated

average times it derived from employees’ representative testimony, was

impermissible. 328 U. S., at 689; see 149 F. 2d, at 465 (“It does not

suffice for the employee to base his right to recover on a mere estimated

average of overtime worked.”).

Cite as: 577 U. S. ____ (2016) 13

THOMAS, J., dissenting

jected class-action plaintiffs’ theory that waiting in an

antitheft security screening line constitutes work. See

Integrity Staffing Solutions, Inc., 574 U. S. at ___ (slip op.,

at 1). The majority thus puts employers to an untenable

choice. They must either track any time that might be the

subject of an innovative lawsuit, or they must defend class

actions against representative evidence that unfairly

homogenizes an individual issue. Either way, the major-

ity’s misinterpretation of Mt. Clemens will profoundly

affect future FLSA-based class actions—which have al-

ready increased dramatically in recent years. Erichson,

CAFA’s Impact On Class Action Lawyers, 156 U. Pa. L.

Rev. 1593, 1617 (2008).

C

The majority makes several other arguments why Mer-

icle’s study was adequate common proof of all class mem-

bers’ experiences. None has merit.

First, the majority contends that, because Tyson’s trial

defense—that Mericle’s study was unrepresentative or

inaccurate—was “itself common,” Tyson was “not de-

prive[d] . . . of its ability to litigate individual defenses.”

Ante, at 12. But looking to what defenses remained avail-

able is an unsound way to gauge whether the class-action

device prevented the defendant from mounting individual-

ized defenses. That Tyson was able to mount only a com-

mon defense confirms its disadvantage. Testifying class

members attested to spending less time on donning and

doffing than Mericle’s averages would suggest. Had Tyson

been able to cross-examine more than four of them, it may

have incurred far less liability. See supra, at 9–10.

Second, the majority argues that Tyson’s failure to

challenge Mericle’s testimony under Daubert v. Merrell

Dow Pharmaceuticals, Inc., 509 U. S. 579 (1993), left to

the jury any remaining questions about the value of this

evidence. Ante, at 14–15. But Comcast rejected this

14 TYSON FOODS, INC. v. BOUAPHAKEO

THOMAS, J., dissenting

argument. Failing to challenge evidence under Daubert

precludes defendants from “argu[ing] that [the] testimony

was not admissible,” but it does not preclude defendants

from “argu[ing] that the evidence failed to show that the

case is susceptible to awarding damages on a class-wide

basis.” Comcast, 569 U. S., at ___, n. 4 (slip op., at 5, n. 4)

(internal quotation marks omitted).

Finally, the majority’s attempts to distinguish this case

from Wal-Mart are unavailing. See ante, at 13–14. Wal-

Mart involved a nationwide Title VII class action alleging

that Wal-Mart’s policy of delegating employment decisions

to individual store managers let managers exercise their

discretion in a discriminatory manner. See 564 U. S., at

342. We held that discretionary decisionmaking could not

be a common policy uniting all class members’ claims

because managers presumptively exercise their discretion

in an individualized manner. See id., at 355–356. Some

may rely on performance-based criteria; others may use

tests; yet others might intentionally discriminate. Ibid.

Because of this variability, “demonstrating the invalidity

of one manager’s use of discretion will do nothing to

demonstrate the invalidity of another’s.” Ibid.

Moreover, the Wal-Mart plaintiffs’ representative evi-

dence—120 employee anecdotes—did not make this indi-

vidualized issue susceptible to common proof. Id., at 358.

Using 120 anecdotes to represent the experiences of 1.5

million class members was too far below the 1:8 ratio of

anecdotes to class members that our prior cases accepted.

Ibid. Thus, this representative evidence was “too weak to

raise any inference that all the individual, discretionary

personnel decisions are discriminatory.” Ibid.

The plaintiffs’ reliance on Mericle’s study fails for the

same reasons. Just as individual managers inherently

make discretionary decisions differently, so too do individ-

ual employees inherently spend different amounts of time

donning and doffing. And, just as 120 employee anecdotes

Cite as: 577 U. S. ____ (2016) 15

THOMAS, J., dissenting

could not establish that all 1.5 million class members

faced discrimination, neither can Mericle’s study establish

that all 3,344 class members spent the same amount of

time donning and doffing. Like the 120 Wal-Mart anec-

dotes, Mericle’s study—which used about 57 employees

per activity to extrapolate times for 3,344—falls short of

the 1:8 ratio this Court deems “significant” to the proba-

tive value of representative evidence. See id., at 358.

III

I agree with the majority’s conclusion in Part II–B that

we should not address whether a class action can be main-

tained if a class contains uninjured members. Given that

conclusion, however, I am perplexed by the majority’s

readiness to suggest, in dicta, that Tyson’s opposition to

bifurcating the proceedings might be invited error. Ante,

at 17. I see no reason to opine on this issue.

* * *

I respectfully dissent.