The U.S. Supreme Court has upheld the use of statistical sampling evidence to establish liability and damages in a “donning and doffing” overtime class action under the Fair Labor Standards Act (FLSA) and state wage law. Tyson Foods, Inc. v. Bouaphakeo, No. 14-1146, 2016 WL 1092414 (U.S. Mar. 22, 2016).

Business groups had urged the Court to prohibit the use of statistical or “representative” evidence in class actions, arguing that a “trial by formula” ignores differences among individual class members and violates a defendant’s due process right to litigate defenses to individual claims.

The Court declined to adopt “broad and categorical rules” permitting or prohibiting this evidence in class actions. Instead, the Court held that the admissibility of statistical sampling evidence turns on whether the evidence is “reliable in proving or disproving the elements of the relevant cause of action” in the particular case, and not on whether the case is an individual or class action.

The Court upheld use of the sampling evidence in Tyson because, under FLSA precedent, the employer’s failure to maintain adequate overtime records meant that the employees could rely on the sampling to “fill an evidentiary gap.” And because the employees could have introduced this evidence in an individual case, they were entitled to use the evidence in a class action. The Court cautioned, however, that “the fairness and utility of statistical methods in contexts other than those presented here will depend on the facts and circumstances particular to those cases.”

The decision undoubtedly will lead to increased litigation over the propriety of using statistical evidence to support class certification and merits decisions. Furthermore, with this decision, it is even more important for employers to maintain accurate time records of all hours by their employees, including time spent in necessary preparation for actual work. Employers are under closer scrutiny and must require all workers to clock in and out consistently and without exception. Ultimately, accurate and reliable time records are the best evidence of compensable time worked. By being able to place actual time (and payroll) records into evidence, employers best position themselves to counter any arguments suggesting the need “to fill an evidentiary gap.”


The FLSA requires employers to pay overtime to covered employees who work more than 40 hours per week, including time spent on activities “integral and indispensable” to their work. The FLSA also requires employers to maintain records of the “wages, hours, and other conditions and practices of employment.”[1]

The plaintiffs in Tyson worked at a pork processing plant and were required to wear protective gear. Some, but not all, were given overtime pay for “donning and doffing” their gear, but the employer did not record all time spent on these activities.

Because the employer did not keep adequate records of “donning and doffing” time, the employees submitted a study by an industrial relations expert who had conducted 744 videotaped observations and estimated that the average time employees spent on these activities each day was 18 or 21.25 minutes, depending on the plant department. The expert added these averages to the timesheets of each employee and opined on which employees worked more than 40 hours a week, as well as on the alleged value of classwide recovery.

The employer argued that use of the sampling evidence was improper because the time each employee took to don and doff varied, and because applying the sampling evidence classwide could result in recovery for some employees who did not actually work more than 40 hours a week. But the employer neither moved for a Daubert hearing[2] challenging the validity of the sampling nor submitted its own expert rebuttal testimony.

The district court certified a “hybrid” action: a collective action as to the FLSA claims,[3] and a class action under Federal Rule of Civil Procedure 23(b)(3) as to the state wage claims. The case went to a jury, which awarded the class $2.9 million in unpaid wages; a subsequent liquidated damages award brought the total to $5.8 million. The Eighth Circuit affirmed. In a 6-2 decision, the Supreme Court affirmed the lower courts’ decisions.

The Supreme Court’s Decision

The Court first assumed, without deciding, that the standard for certifying an FLSA collective action was “no more stringent” than that of a Rule 23 class action. The Court therefore analyzed the class issues under Rule 23 and applied Rule 23 principles to the FLSA claims.

The Court next held that to establish entitlement to overtime pay, each employee must prove that the time spent donning and doffing, when added to his or her regular hours, amounted to more than 40 hours in any given week. The “central dispute,” therefore, was whether it was appropriate to assume that each employee donned and doffed for the same average time estimated by the plaintiffs’ expert. The Court concluded that, under the circumstances of this case, it was.

Citing a 1946 FLSA case,[4] the Court held that given the “evidentiary gap created by the employer’s failure to keep adequate records,” the employees would have been entitled to submit evidence of the survey even if they had brought their claims individually. As a result, they were also permitted to use the sample in the class action.

The Court held that this result was consistent with Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338 (2011), which rejected the use of sampling in an employment discrimination case: “Wal-Mart does not stand for the broad proposition that a representative sample is an impermissible means of establishing classwide liability.” The Court held that the employees in Dukes were not similarly situated, and therefore could not have used the sampling evidence to establish liability in an individual case. By contrast, each employee in Tyson, the Court held, “worked in the same facility, did similar work, and was paid under the same policy.”

The Court cautioned, however, that not all “representative evidence” can establish classwide liability. “Representative evidence that is statistically inadequate or based on implausible assumptions could not lead to a fair or accurate estimate of the uncompensated hours an employee has worked.” But because the employer did not raise a Daubert challenge to the plaintiffs’ expert report, there was no basis to conclude that the district court erred in admitting the sampling evidence.

Finally, the Court declined to address the employer’s argument that some class members were not entitled to overtime, and therefore were not injured and should not recover damages. The Court held that because the damages award had not yet been allocated to class members, the employer could challenge the proposed method of allocation when it came time to disburse the award. In a concurring opinion, Chief Justice Roberts expressed his “concern” about this issue, but concluded that the district court should address it on remand: “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. . . . If there is no way to ensure that the jury’s damages award goes only to injured class members, that award cannot stand.”

Justices Thomas and Alito dissented, arguing that the majority had improperly “redefin[ed] class-action requirements and devis[ed] an unsound special evidentiary rule for [FLSA] cases.” They also concluded that the majority’s approach “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.”

[1] 29 U.S.C. § 211(c).

[2] Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).

[3] 29 U.S.C. § 216.

[4] Anderson v. Mt. Clemens Pottery Co., 328 U.S. 680 (1946).