Court Opinion

ID: 9368012
Source: CourtListenerOpinion
Date Created: 2023-02-02 18:00:48.088991+00
Date Added: 2024-06-11T17:16:05.508237
License: Public Domain

FOR PUBLICATION

         UNITED STATES COURT OF APPEALS
              FOR THE NINTH CIRCUIT

CASEY CLARKSON,                                   No. 21-35473

                 Plaintiff-Appellant,          D.C. No. 2:19-cv-
                                                 00005-TOR
    v.

ALASKA AIRLINES, INC.;                              OPINION
HORIZON AIR INDUSTRIES, INC.,

                 Defendants-Appellees.

         Appeal from the United States District Court
           for the Eastern District of Washington
          Thomas O. Rice, District Judge, Presiding

           Argued and Submitted October 21, 2022
                     Portland, Oregon

                     Filed February 1, 2023

     Before: Richard A. Paez and Bridget S. Bade, Circuit
     Judges, and Haywood S. Gilliam, Jr., * District Judge.

                     Opinion by Judge Paez

*
  The Honorable Haywood S. Gilliam, Jr., United States District Judge
for the Northern District of California, sitting by designation.
2               CLARKSON V. ALASKA AIRLINES, INC.

                          SUMMARY **

                            Labor Law

    The panel reversed the district court’s grant of summary
judgment in favor of defendants Alaska Airlines, Inc., and
Horizon Air Industries, Inc., and remanded, in a class action
brought under the Uniformed Services Employment and
Reemployment Rights Act (USERRA) by Casey Clarkson,
a commercial airline pilot and military reservist.
    Clarkson alleged that because the airlines provided paid
leave for non-military leaves, including jury duty,
bereavement, and sick leave, the airlines were also required
to pay pilots during short-term military leaves of thirty days
or less.
    Under USERRA § 4316(b)(1), “a person who is absent
from a position of employment by reason of service in the
uniformed services” shall be “deemed to be on furlough or
leave of absence” and shall be “entitled to such other rights
and benefits not determined by seniority as are generally
provided by the employer” to other employees on non-
military furloughs or leaves of absence. Under 20 C.F.R. §
1002.150, the “non-seniority rights and benefits to which an
employee is entitled during a period of service are those that
the employer provides to similarly situated employees.” If
the benefits vary according to the type of leave, the
employee must be given “the most favorable treatment
accorded to any comparable form of leave when he or she

**
   This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
               CLARKSON V. ALASKA AIRLINES, INC.              3

performs service in the uniformed services.” To determine
whether types of leave are comparable, the duration of the
leave must be considered, as well as the purpose of the leave
and the ability of the employee to choose when to take the
leave.
    The panel held that the district court erred in concluding
that no reasonable jury could find military leave comparable
to non-military leave. In reaching this conclusion, the
district court erred by comparing all military leaves, rather
than just the short-term military leaves at issue here, with the
comparator non-military leaves. The district court also erred
by disregarding factual disputes about each of the three
factors in the comparability analysis: duration, purpose, and
control. The panel held that because factual disputes
existed, comparability was an issue for the jury.
    The panel therefore reversed and remanded. It instructed
that on remand, the district court should consider in the first
instance the issue whether “pay during leave” was a
standalone benefit that the airlines provided under their
collective bargaining agreements to any employee on leave.
4            CLARKSON V. ALASKA AIRLINES, INC.

                       COUNSEL

Jonathan E. Taylor (argued), Deepak Gupta, Peter Romer-
Friedman, and Robert Friedman, Gupta Wessler PLLC,
Washington, D.C.; Adam T. Klein and Michael J. Scimone,
Outten & Golden LLP, New York, New York; Vincent
Chang, Block & Leviton LLP, San Francisco, California; R.
Joseph Barton and Colin M. Downes, Block & Leviton LLP,
Washington, D.C.; Matthew Z. Crotty, Crotty & Son Law
Firm PLLC, Spokane, Washington; Thomas G. Jarrard, The
Law Office of Thomas G. Jarrard PLLC, Spokane,
Washington; for Plaintiff-Appellant.

Anton Metlitsky (argued), Mark W. Robertson, and Charles
Mahoney, O’Melveny & Myers LLP, New York, New York;
Jason Zarrow, O’Melveny & Myers LLP, Los Angeles,
California; Tristan Morales, O’Melveny & Myers LLP,
Washington, D.C.; Steven W. Fogg, Corr Cronin LLP,
Seattle, Washington; Kathryn S. Rosen, Davis Wright
Tremaine LLP, Seattle, Washington; for Defendants-
Appellees.

David T. Raimer and Douglas W. Hall, Jones Day,
Washington, D.C., for Amicus Curiae Airlines for America.
              CLARKSON V. ALASKA AIRLINES, INC.             5

                         OPINION

PAEZ, Circuit Judge:

    For over sixty years, our nation has encouraged military
service by continually easing the burden on servicemembers
who must juggle military duties with civilian jobs. In the
Selective Training and Service Act of 1940, Congress
ensured for the first time—but not the last—that veterans
returning to civilian jobs would not face discrimination on
account of their service. Over the succeeding decades, re-
employment rights were extended to military reservists and
National Guardsmen. These protections remain all the more
important today, as our nation relies on an all-volunteer
military force. Indeed, just as the draft came to an end,
Congress expanded servicemembers’ protections in the
Veterans’ Reemployment Rights Act of 1974. Congress
continued its tradition of recognizing the sacrifice and
dedication of servicemembers in 1994 by enacting the
Uniformed Services Employment and Reemployment
Rights Act (“USERRA”). Today, USERRA § 4316(b)(1)
requires employers to provide employees who take military
leave with the same non-seniority rights and benefits as their
colleagues who take comparable non-military leaves. See 38
U.S.C. § 4316(b)(1); 20 C.F.R. § 1002.150(a).
    Casey Clarkson (“Clarkson”), a commercial airline pilot
and military reservist, claims that his employers failed to
abide by this rule. Clarkson alleges that because Alaska
Airlines and Horizon Air Industries (collectively, the
“Airlines”) provide paid leave for non-military leaves
including jury duty, bereavement, and sick leave, the
Airlines are also required to pay pilots during short-term
military leaves. The district court disagreed, granting
6                  CLARKSON V. ALASKA AIRLINES, INC.

summary judgment to the Airlines and concluding as a
matter of law that military leave is not comparable to any
other form of leave offered by the Airlines. We reverse.
               I. STATUTORY BACKGROUND
                                    A.
    Enacted in 1994, USERRA 1 contains “the most
expansive protection to servicemembers yet enacted . . .
[and] entitle[s] reservists and other military personnel to
certain employment benefits while on leave.” Travers v.
Fed. Express Corp., 8 F.4th 198, 201 (3d Cir. 2021) (cleaned
up). 2 USERRA serves three primary purposes: (1) “[T]o
encourage noncareer service in the uniformed services by
eliminating or minimizing the disadvantages to civilian
careers and employment which can result from such
service”; (2) “to minimize . . . disruption . . . by providing
for the prompt reemployment of [persons performing
military service] upon their completion of such service”; and
(3) “to prohibit discrimination against persons because of
their service in the uniformed services.” 38 U.S.C. § 4301.
    In short, USERRA recognizes that those who serve in the
military should be supported, rather than penalized, for their
service. USERRA enables servicemembers to strike a
balance between fulfilling their military duties and civilian
obligations, including civilian jobs, without suffering
discrimination. See Travers, 8 F.4th at 199. While
USERRA is “the most recent in a series of laws protecting

1
    Pub. L. No. 103-353, 108 Stat. 3149 (codified at 38 U.S.C. § 4301).
2
  For a fuller recounting of the history of USERRA and its predecessor
statutes, see Travers v. Fed. Express Corp., 8 F.4th 198 (3d Cir. 2021),
and Rogers v. City of San Antonio, 392 F.3d 758 (5th Cir. 2004).
                CLARKSON V. ALASKA AIRLINES, INC.                   7

veterans’ employment and reemployment rights,” Rogers v.
City of San Antonio, 392 F.3d 758, 762 (5th Cir. 2004),
Congress intended USERRA to build on the rights
established in its predecessor statutes, including the
Selective Training and Service Act of 1940 (“STSA”), Pub.
L. No. 783, 54 Stat. 885, 890, and the Veterans’
Reemployment Rights Act of 1974 (“VRRA”), Pub. L. No.
93-508, 88 Stat. 1578, 1594 (codified at 38 U.S.C. § 2021).
See also Travers, 8 F.4th at 199-201. The “large body of
case law that had developed under those statutes remain[s]
in full force and effect.” Rogers, 392 F.3d at 762 (quoting
20 C.F.R. § 1002.2). An understanding of the history of
these protective statutes and the corresponding case law is
thus critical to our evaluation of this case.
    USERRA’s predecessor statutes guaranteed that
servicemembers who took leave from a civilian job for
military service could return to that job without losing
“seniority, status, or pay.” STSA, Pub. L. No. 783, § 8(b),
54 Stat. 885, 890; VRRA, Pub. L. No. 93-508, § 2021(a), 88
Stat. 1578, 1595. These rights were extended to military
reserve members and National Guardsmen throughout the
1950s and 1960s. See, e.g., Pub. L. No. 305, § 261(f), 69
Stat. 598, 602 (1955); Pub. L. No. 86-632, § 5, 74 Stat. 467,
468 (1960); accord Monroe v. Standard Oil Co., 452 U.S.
549, 555 (1981); Rogers, 392 F.3d at 764. Reservists,
however, did not receive “protection against discharges,
demotions, or other discriminatory conduct once reinstated”
until 1968. Monroe, 452 U.S. at 556-60. At that time,
Congress enacted what became § 2021(b)(3) of the VRRA, 3

3
  Before 1974, veterans’ re-employment rights provisions were codified
at 50 U.S.C. § 459. These provisions were recodified without
8               CLARKSON V. ALASKA AIRLINES, INC.

which provides: “Any person [employed by a private
employer] shall not be denied retention in employment or
any promotion or other incident or advantage of employment
because of any obligation as a member of a reserve
component of the Armed Forces of the United States.” Pub.
L. No. 90-491, 82 Stat. 790 (1968).
    Both the House and Senate Reports on the proposed
legislation explained that § 2021(b)(3) would “assure[] that
these reservists will be entitled to the same treatment
afforded their coworkers without such military obligation.”
H.R. Rep. No. 90-1303, at 3 (1968); accord S. Rep. No. 90-
1477, at 1-2 (1968). By protecting reservists from
discrimination, the provision would encourage voluntary
military service. See Monroe, 452 U.S. at 557-60. In 1981,
the Supreme Court clarified in Monroe that § 2021(b)(3)
entitled reservists to equal, but not preferential, treatment as
compared to their non-military coworkers. Id. at 557-66.
    Five years after the Court decided Monroe, the Third
Circuit considered the application of § 2021(b)(3) in
Waltermyer v. Aluminum Co., 804 F.2d 821 (3d Cir. 1986).
There, the Third Circuit concluded that a National
Guardsman was entitled to holiday pay for a holiday that
occurred while he was on military leave because employees
on non-military leaves, including jury duty, bereavement
leave, and sick leave, received holiday pay. Id. at 825.
Although the collective bargaining agreement limited
holiday pay to employees who worked during the holiday
week or employees on certain enumerated leaves (which did
not include military leave), the court concluded that the list

substantive change in the VRRA. See Coffy v. Republic Steel Corp., 447
U.S. 191, 194 n.2 (1980).
              CLARKSON V. ALASKA AIRLINES, INC.              9

of enumerated leaves focused on “involuntary” leaves. Id.
Because the National Guardsman’s military leave was also
involuntary, the court held that it would be equitable, and not
preferential, to require the employer to provide holiday pay
under § 2021(b)(3). Id.
   Congress later codified the Waltermyer decision in
USERRA § 4316(b)(1), the provision at issue here. As the
House Report on the bill explained:

       The Committee intends to affirm the decision
       in Waltermyer v. Aluminum Co. of America,
       804 F.2d 821 (3d Cir. 1986) that, to the extent
       the employer policy or practice varies among
       various types of non-military leaves of
       absence, the most favorable treatment
       accorded any particular leave would also be
       accorded the military leave, regardless of
       whether the non-military leave is paid or
       unpaid.

H.R. Rep. 103-65, pt. 1, at 33-34 (1993); accord S. Rep. 103-
158, at 58 (1993).
                              B.
    Section 4316(b)(1) expanded non-seniority employment
benefits for servicemembers, including reservists and
Guardsmen, who must take leave from civilian jobs to
perform their military duties. Under § 4316(b)(1), “a person
who is absent from a position of employment by reason of
service in the uniformed services” shall be “deemed to be on
furlough or leave of absence,” and shall be “entitled to such
other rights and benefits not determined by seniority as are
generally provided by the employer” to other employees on
10               CLARKSON V. ALASKA AIRLINES, INC.

non-military furloughs or leaves of absence. 38 U.S.C. §
4316(b)(1). 4
    The Department of Labor’s (“DOL”) implementing
regulation for § 4316(b)(1) explains that the “non-seniority
rights and benefits to which an employee is entitled during a
period of service are those that the employer provides to
similarly situated employees by an employment contract,
agreement, policy, practice, or plan in effect at the
employee’s workplace.” 20 C.F.R. § 1002.150(a). The
regulation then explains that if the benefits vary according to
the type of leave, the employee must be given “the most
favorable treatment accorded to any comparable form of
leave when he or she performs service in the uniformed
services.” Id. at § 1002.150(b) (emphasis added). The
regulation also explains how to determine if types of leave
are comparable:

         To determine whether any two types of leave
         are comparable, the duration of the leave may
         be the most significant factor to compare.
         For instance, a two-day funeral leave will not
         be “comparable” to an extended leave for
         service in the uniformed service. In addition
         to comparing the duration of the absences,

4
 Under USERRA, the term “rights and benefits” is defined as “the terms,
conditions, or privileges of employment, including any advantage, profit,
privilege, gain, status, account, or interest (including wages or salary for
work performed) that accrues by reason of an employment contract or
agreement or an employer policy, plan, or practice and includes rights
and benefits under a pension plan, a health plan, an employee stock
ownership plan, insurance coverage and awards, bonuses, severance pay,
supplemental unemployment benefits, vacations, and the opportunity to
select work hours or location of employment.” 38 U.S.C. § 4303(2).
                 CLARKSON V. ALASKA AIRLINES, INC.                     11

         other factors such as the purpose of the leave
         and the ability of the employee to choose
         when to take the leave should also be
         considered.

Id. at § 1002.150(b). Clarkson challenges the Airlines’
compliance with this regulation.
         II. DISTRICT COURT PROCEEDINGS
    Clarkson filed this action against the Airlines in 2019,
alleging that the Airlines violated § 4316(b)(1) of USERRA
by failing to pay pilots who took short-term military leave
while paying pilots who took comparable non-military
leaves. He filed the action on behalf of himself and all others
similarly situated. The district court certified a “Paid Leave
Class” in August 2020, defined as: “All current or former
Alaska or Horizon pilots who have taken short-term military
leave from October 10, 2004 through the date of the
judgment.” Although the certification order did not define
short-term military leave, the parties and court understood it
to mean military leaves of thirty days or less. Clarkson and
the members of the class were or are employed as pilots by
Alaska or Horizon. While employed, Clarkson and the other
class members took at least one military leave of thirty days
or less. These facts are undisputed.
    What the parties cannot agree on, however, is whether
short-term military leave is comparable to the non-military
leaves offered by the Airlines, namely jury duty,
bereavement leave, or sick leave. 5 In seeking summary

5
  Clarkson also argues that vacation leave may be comparable to short-
term military leave. The Airlines do not address vacation leave, asserting
that such argument is precluded because Clarkson did not specifically
identify vacation leave as a comparator in his complaint. Clarkson’s
12               CLARKSON V. ALASKA AIRLINES, INC.

judgment, the Airlines argued that military leave is not
comparable to non-military leave as a matter of law. In the
alternative, the Airlines argued that even if the leaves were
comparable, “pay during leave” is not a benefit offered in
their collective bargaining agreements (“CBAs”) to which
the class members are entitled. Clarkson did not address this
second argument, and instead argued that a reasonable jury
could find that some or all of the non-military leaves offered
by the Airlines are comparable to short-term military leave.
    As in the district court, the parties’ arguments focus on
the three comparability factors outlined in the regulation: (1)
duration of leave, (2) purpose of leave, and (3) ability of the
employee to choose when to take the leave (also referred to
as “control”). 20 C.F.R. § 1002.150(b). In the district court,
each side submitted an expert report comparing the duration
of military leave to the duration of other types of leave. The
Airlines’ expert conducted his analysis using all military
leaves rather than just short-term military leaves of thirty
days or less, analyzed the frequency of leaves, and focused
on the length of leaves at the highest percentiles rather than
the average lengths. As a result, his comparator numbers
look quite different from the numbers produced by
Clarkson’s expert, who focused on the average, mode, and
median days taken of short-term military leave. The parties

complaint repeatedly references “other” types of leave besides jury duty,
bereavement, and sick leave, and Clarkson included vacation as a
comparator leave in his opposition to summary judgment. However, the
district court did not address vacation leave as a comparator. Because it
is clear that a reasonable jury could find jury duty, bereavement, or sick
leave comparable to short-term military leave, we need not address
vacation leave to reverse the grant of summary judgment. On remand,
the district court may address vacation leave as a comparator in the first
instance.
                  CLARKSON V. ALASKA AIRLINES, INC.        13

also presented conflicting evidence about the purpose of
military leave and the ability of pilots to control when they
take such leave. The Airlines contend that pilots take
military leave to pursue a parallel career, while Clarkson
maintains that military leave allows pilots to perform a civic
duty and public service. The Airlines also contend that pilots
have near total control over when to take military leave,
while Clarkson argues that the military schedule is not so
flexible.
    On each factor, the district court determined there were
no genuine issues of material fact and concluded that
military leave is not comparable to any other leave as a
matter of law. The district court thus did not address the
“pay during leave” issue and granted summary judgment to
the Airlines. Clarkson timely appealed. 6 We reverse.
                 III. STANDARD OF REVIEW
    We review de novo a district court’s summary judgment
ruling to determine whether “there are any genuine disputes
of material fact and whether the district court correctly
applied the relevant substantive law.” Reynaga v. Roseburg
Forest Products, 847 F.3d 678, 685 (9th Cir. 2017) (quoting
Dominguez-Curry v. Nevada Trans. Dep’t, 424 F.3d 1027,
1033 (9th Cir. 2005)). “An issue of fact is genuine ‘if the
evidence is such that a reasonable jury could return a verdict
for the nonmoving party.’” Id. at 685-86 (quoting Villiarimo
v. Aloha Island Air, Inc., 281 F.3d 1054, 1061 (9th Cir.
2002)). A grant of summary judgment is “proper only where
there is no genuine issue of any material fact or where
viewing the evidence and the inferences which may be
drawn therefrom in the light most favorable to the adverse

6
    We have jurisdiction under 28 U.S.C. § 1291.
14             CLARKSON V. ALASKA AIRLINES, INC.

party, the movant is clearly entitled to prevail as a matter of
law.” Sandvik v. Alaska Packers Ass’n, 609 F.2d 969, 974
(9th Cir. 1979) (quoting Smith v. Gross, 604 F.2d 639, 641
(9th Cir. 1979)). As we discuss below, the district court
failed to heed these summary judgment principles in its
comparability analysis.
                     IV. DISCUSSION
    In entering judgment for the Airlines, the district court
concluded that no reasonable jury could find military leave
comparable to non-military leave.           In reaching this
conclusion, the district court erred by comparing all military
leaves, rather than just the short-term military leaves at issue
here, with the comparator non-military leaves. The court
also erred by disregarding countless factual disputes about
each of the three factors in the comparability analysis:
duration, purpose, and control. The court seemingly
considered only the evidence presented by the Airlines when
it concluded no reasonable jury could find for Clarkson.
Because factual disputes exist, comparability is an issue for
the jury.
     A. Under USERRA, Courts Must Consider the
     Length of Leave at Issue
    In concluding that military leave is not comparable to
other leaves as a matter of law, the district court first agreed
with the Airlines that military leave must be considered as a
“general category of leave,” Clarkson v. Alaska Airlines,
Inc., 2021 WL 2080199, at *4 (E.D. Wash. May 24, 2021),
rather than in an “individualized analysis.” Id. at *5. The
district court thus decided that all military leaves taken by
pilots at the Airlines—whether two days or two years—must
be grouped together when assessing the most significant
comparability factor: duration. 20 C.F.R. § 1002.150(b).
              CLARKSON V. ALASKA AIRLINES, INC.            15

    Although we have not yet addressed whether military
leave should be considered based on its length or
categorically when assessing USERRA violations, we hold
that examining the length of leave at issue is the correct
approach. Cf. Paige v. California, 291 F.3d 1141, 1147 (9th
Cir. 2002) (determining the proper comparator groups is a
question of law). The plaintiff, as master of the complaint,
can limit the request for recovery of benefits to specific,
shorter military leaves. To follow the district court’s
approach and consider military leaves categorically would
render USERRA’s protections meaningless. Military leaves
vary greatly in length, and the longest leaves can last years.
Were we to adopt a categorical approach to military leaves,
no other type of leave would look similar, and
servicemembers would not be protected under § 4316(b)(1).
    Indeed, the statute’s implementing regulation suggests
that the military leave at issue should be compared with the
alleged comparable leaves. Section 1002.150 states that
duration is the most significant factor to compare when
determining if “any two types of leave are comparable.” In
context, “any two types of leave” must refer to (1) military
leave and (2) another employer-offered leave. As the
regulation explains, “a two-day funeral leave will not be
‘comparable’ to an extended leave for service.” 20 C.F.R.
1002.150(b). But while an “extended” military leave is not
comparable to a “two-day funeral leave,” it is entirely
possible that a two-day military leave is comparable to a
two-day funeral leave.
    Although our sister circuits have not addressed this
question directly, their opinions support the conclusion that
a plaintiff may define his claim by the particular length of
the military leave at issue. As the Seventh Circuit explained:
“It is up to the employee to demonstrate that any given
16               CLARKSON V. ALASKA AIRLINES, INC.

stretch of military leave is comparable to a form of
nonmilitary leave that is accorded a benefit.” White v.
United Airlines, Inc., 987 F.3d 616, 624 (7th Cir. 2021)
(emphasis added). 7
    We thus conclude that the district court erred when it
compared non-military leaves offered by the Airlines to all
military leaves taken by pilots at the Airlines. Clarkson
limited his claim to military leaves of thirty days or less.
Thus, the relevant question is whether such short-term leaves
are comparable to the other leaves offered by the Airlines.
As discussed next, this is a question for the jury.
     B. Whether Short-Term Military Leave Is
     Comparable to Other Types of Leaves Is a Jury
     Question
     “Comparability is a question of fact.” Syufy Enters. v.
Am. Multicinema, Inc., 793 F.2d 990, 1003 (9th Cir. 1986).
It is thus a question for the jury unless “the facts of a case
suggest that no reasonable jury could see enough
commonality for a meaningful comparison.” Howell v.

7
  The district court acknowledged White but stated it “is not inclined to
apply the Seventh Circuit’s White holding to this case, as the Ninth
Circuit has not yet spoken on the issue.” Clarkson, 2021 WL 2080199
at *5. The Fifth Circuit has also denied summary judgment in a similar
§ 4316(b)(1) case, noting that there “are genuinely disputable issues as
to the material facts of whether involuntary non-military leaves, not
generally for extended durations . . . are comparable to each plaintiff’s
military leaves taken for service in the uniformed services.” Rogers, 392
F.3d at 771-72 (emphasis added); see also Tully v. Dep’t of Just., 481
F.3d 1367, 1368 (Fed. Cir. 2007) (holding that employee was not entitled
to holiday pay because a two-and-a-half-year military leave was not
comparable to other leaves); Waltermyer, 804 F.2d at 825 (holding that
employee was entitled to holiday pay because a two-week military leave
was comparable to other leaves).
              CLARKSON V. ALASKA AIRLINES, INC.             17

Wexford Health Sources, Inc., 987 F.3d 647, 657 (7th Cir.
2021) (quoting Rozumalski v. W.F. Baird & Assocs., Ltd.,
937 F.3d 919, 927 (7th Cir. 2019)) (holding that
comparability in employment discrimination cases is a jury
question); see also Wheeler v. Georgetown Univ. Hosp., 812
F.3d 1109, 1116 (D.C. Cir. 2016) (same); Graham v. Long
Island R.R., 230 F.3d 34, 39 (2d Cir. 2000) (same).
    The district court considered the three factors outlined in
the regulation—duration, purpose, and control—and found
that no jury could find in Clarkson’s favor given “significant
differences” between military leave and non-military leave
as to each factor. The district court thus granted the Airlines
summary judgment because it found that there “are no
genuine issues of material fact as to whether military leave
is comparable to other forms of leave covered by the CBAs;
they are not comparable.” Clarkson, 2021 WL 2080199 at
*9.
    This conclusion was erroneous. At the summary
judgment stage, “the judge’s function is not . . . to weigh the
evidence and determine the truth of the matter[,] but to
determine whether there is a genuine issue for trial.”
Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 249 (1986).
As explained below, the record evidence presents genuine
issues of material fact as to each factor that, when viewed in
the light most favorable to Clarkson, would allow a
reasonable jury to find in his favor.
   1. Duration
    Duration is the “most significant factor” in the
comparability analysis. 20 C.F.R. § 1002.150(b). After
considering the evidence, the district court determined that
“[g]iven the significant differences in duration and
frequency, military leave is not comparable to jury duty,
18             CLARKSON V. ALASKA AIRLINES, INC.

bereavement leave, and sick leave.” Clarkson, 2021 WL
2080199 at *6. This holding ignored significant factual
disputes over the leave data presented by the Airlines. The
district court’s analysis was also flawed by including
frequency as an integral factor in the duration analysis.
       a. Disputed statistical evidence
    Although the parties agree on the underlying dataset
regarding the duration of military and non-military leaves,
their agreement ends there. Each side’s expert used that
dataset to present different opinions on the comparability of
the duration of military and non-military leave. When
parties “offer conflicting inferences drawn from the
[statistical] evidence . . . there is a genuine dispute of
material fact . . . and [the] action must proceed to trial.”
Paige, 291 F.3d at 1147. It is for the jury, not the court, to
decide how to weigh these conflicting inferences. Tyson
Foods, Inc. v. Bouaphakeo, 577 U.S. 442, 459 (2016) (“Once
a district court finds evidence to be admissible, its
persuasiveness is, in general, a matter for the jury.”); City of
Pomona v. SQM N. Am. Corp., 750 F.3d 1036, 1049 (9th Cir.
2014) (“Where two credible experts disagree, it is the job of
the fact finder, not the trial court, to determine which source
is more credible and reliable.”).
    Instead of recognizing this factual dispute, the district
court adopted the Airlines’ evidence and granted their
motion for summary judgment. In its analysis of the parties’
arguments, the court failed to consider the evidence in the
light most favorable to Clarkson. Instead, the court relied
only on the Airlines’ statistical evidence. This is evident
from the district court’s repeated references to the Airlines’
Reply Statement of Material Facts, including to several facts
that Clarkson disputes or materially clarifies. Further, as
                 CLARKSON V. ALASKA AIRLINES, INC.                    19

discussed below, the district court’s review of the statistical
evidence was tainted by its decision to consider military
leave categorically.
    To conclude that the leaves are incomparable, the district
court compared the longest military leave (185 days at
Alaska, excluding the 99th percentile, and 70 days at
Horizon, excluding the 95th percentile) with the longest jury
duty leave (6 days at Alaska and 5 days at Horizon), the
longest bereavement leave (6 days at Alaska and 3 days at
Horizon), and the longest sick leave (5 days at Alaska and 4
days at Horizon). 8 But Clarkson presented a different
analysis of the data in his opposition to summary judgment.
His analysis showed that Alaska pilots took an average of
3.10 days of short-term military leave, 2.94 days of jury duty
leave, 2.77 days of bereavement leave, and 2.52 days of sick
leave. 9 Horizon pilots took an average of 4.23 days of short-
term military leave, 2.66 days of jury duty leave, 2.48 days
of bereavement leave, and 2.17 days of sick leave. 10 The

8
  The jury duty and bereavement leave data presented by the Airlines
covers the period between October 2004 and December 2020 for Alaska
pilots and between October 2008 and December 2020 for Horizon pilots.
The military leave data described above is from those time periods. The
sick leave data, however, only covers the period from September 2013
to December 2020 for Alaska pilots and from February 2010 to
December 2020 for Horizon pilots. During those periods, the
comparable longest military leave is 122 days for Alaska pilots
(excluding the 99th percentile) and 58 days for Horizon pilots (excluding
the 95th percentile).
9
 Again, because the sick leave data covered a different time period, the
comparable average short-term military leave from September 2013 to
December 2020 is 2.50 days for Alaska pilots.
10
   The comparable average short-term military leave from February 2010
to December 2020 is 4.23 days for Horizon pilots.
20            CLARKSON V. ALASKA AIRLINES, INC.

mode and median days of short-term military leave appear
even more similar to the mode and median days of non-
military leaves. The district court did not mention nor
discuss Clarkson’s analysis. Nor did the district court
mention the Airlines’ expert’s finding that the longest short-
term military leave, which is the appropriate comparator,
was 6 days for Alaska pilots and 9 days for Horizon pilots
(excluding the 90th percentiles). Using these statistical
measures, a reasonable jury could find in Clarkson’s favor.
    As noted above, summary judgment is only appropriate
“where viewing the evidence and the inferences which may
be drawn therefrom in the light most favorable to the adverse
party, the movant is clearly entitled to prevail as a matter of
law.” Sandvik, 609 F.2d at 974 (quoting Smith, 604 F.2d at
641). Here, the evidence put forth by Clarkson—and by the
Airlines—could allow a jury to infer that the duration of
military leave is comparable to the duration of jury duty,
bereavement, or sick leave. The district court erred in
concluding otherwise.
       b. Frequency
    The district court’s decision is also flawed because it
treated frequency as an integral part of the duration analysis.
As the court put it, “frequency is useful in the duration
analysis.” Clarkson, 2021 WL 2080199 at *5. While it is
true that the implementing regulation leaves room for courts
to consider factors besides duration, purpose, and control,
see 20 C.F.R. § 1002.150(b) (“[O]ther factors such as
[purpose and control] should also be considered.” (emphasis
added)), the factors enumerated in the regulation should be
weighed most heavily when considering whether two leaves
are comparable. Cf. Sanders v. City of Newport, 657 F.3d
772, 780-81 (9th Cir. 2011) (interpreting federal labor statute
                 CLARKSON V. ALASKA AIRLINES, INC.                      21

“in light of the text of the pertinent DOL regulations”).
Section 1002.150(b) instructs that duration is the “most
significant” factor in the comparability analysis, and it does
not mention frequency. See 20 C.F.R. § 1002.150(b).
Frequency is not encompassed within duration. Rather, the
two terms convey distinct concepts. Duration is “the time
during which something exists or lasts.” Merriam-Webster
Dictionary,                            https://www.merriam-
webster.com/dictionary/duration (2022). Frequency is “the
number of repetitions of a periodic process in a unit of time.”
Merriam-Webster         Dictionary,    https://www.merriam-
webster.com/dictionary/frequency (2022).
    Including frequency in the duration analysis effectively
undermines the purpose of USERRA. 11 Congress intended
USERRA and its predecessor statutes to protect reservists
during their “frequent absences from work” with the full
understanding that those frequent absences could “cause
considerable inconvenience to an employer.” Monroe, 452
U.S. at 565. Nevertheless, “Congress has provided . . . that
employers may not rid themselves of such inconveniences
and productivity losses by discharging or otherwise
disadvantaging employee-reservists solely because of their
military obligations.” 12 Id.

11
  This error is especially significant given the “canon that provisions for
benefits to members of the Armed Services are to be construed in the
beneficiaries’ favor.” King v. St. Vincent’s Hosp., 502 U.S. 215, 220 n.9
(1991) (citing Fishgold v. Sullivan Drydock & Repair Corp., 328 U.S.
275, 285 (1946)).
12
    Regulations implementing other provisions of USERRA also
explicitly state that “the timing, frequency, and duration of [a] person’s
training or service . . . shall not be a basis for denying protection.” 38
U.S.C. § 4312(h) (emphasis added).
22             CLARKSON V. ALASKA AIRLINES, INC.

    In justifying the use of frequency, the Airlines rely on the
very rationale that Congress sought to prohibit: “The fact
that military duty leave happens much more frequently . . .
than, say, jury duty leave, means that providing paid military
leave is substantially more costly and burdensome to
operations than providing paid jury duty leave.” But
Congress enacted USERRA to “prohibit discrimination
against persons because of their service in the uniformed
services,” 38 U.S.C. § 4301, regardless of whether those
anti-discrimination protections increase employers’ costs
and burdens. See S. Rep. No. 90-1477, at 1 (explaining the
statute was intended to protect reservists who were
discriminated against because of frequent obligations).
    The Airlines also attempt to justify the use of frequency
by arguing that “frequency is highly relevant in this case due
to the peculiar military leave patterns unique to pilots,” who
allegedly take more frequent leaves than other military
reservists. But USERRA is no less protective of pilots than
of any other military reservist.
    The Airlines’ (and amicus’s) policy arguments that pilots
will use their frequent military duties to intentionally create
conflicts to garner double pay, or that airlines will eliminate
benefits such as paid bereavement leave or paid jury duty
leave to avoid paying for military leave, are not compelling.
The Airlines are only required to provide equal treatment,
not preferential treatment, to employees taking military
leave. Thus, if the employer only provides three days of paid
bereavement leave per year or only offers the difference in
pay between the employee’s salary and the compensation for
jury duty (as Horizon does), that is all the employer would
be required to provide to the servicemember. We are thus
unpersuaded by the Airlines’ arguments that a ruling in
              CLARKSON V. ALASKA AIRLINES, INC.             23

Clarkson’s favor would drastically increase costs or
convince employers to cease offering other paid leaves.
   2. Purpose
    In considering the purpose factor, the district court found
that “the evidence supports [the Airlines’] position that a
significant purpose of military leave under the CBAs is to
allow employees to pursue parallel careers.” Clarkson, 2021
WL 2080199 at *7. By accepting this position, the district
court rejected Clarkson’s evidence demonstrating that the
primary purpose of military leave is to perform a civic duty
and public service.
    Clarkson’s argument is both intuitive and well-supported
by the record. In his deposition, Clarkson explained that he
joined the military “to serve.” Alaska representatives also
repeatedly acknowledged in their depositions and answers to
interrogatories that public service is a primary purpose of
military leave. Nonetheless, the Airlines attempt to
undermine Clarkson’s testimony by pointing to a single
question and answer from Clarkson’s deposition:

       Q: Would you consider it           accurate to
          describe military service      for Horizon
          pilots as a second career?
       A: I don’t know if we could       consider it a
          second career. I would          say parallel
          career.

    The district court, however, may not judge credibility,
weigh the evidence, or resolve factual disputes at summary
judgment. See Anderson, 477 U.S. at 255. The court thus
erred when it held that there are no genuine disputes about
24               CLARKSON V. ALASKA AIRLINES, INC.

the purpose of military leave. 13 It is for the jury to determine
how much weight to give to the evidence presented about the
purpose of military leave.
     3. Control
    Finally, the district court found that “pilots have a greater
degree of control over their ability to take military leave and
schedule around such leave” than employees taking non-
military leaves. Clarkson, 2021 WL 2080199 at *8. In so
finding, the district court again accepted the Airlines’ factual
contentions and ignored Clarkson’s factual presentation.
Given the record evidence, however, a reasonable jury could
find that pilots do not have significantly more control over
military duty than they do over other types of leave.
    At both Airlines, pilots bid on their monthly schedules in
advance and must provide notice of known absences,
including scheduled military duty, at the time of bidding.
The scheduling systems are designed to schedule pilots to
avoid these absences, but conflicts can still occur because
bidding takes place by seniority. To avoid conflicts after the
schedules are released, pilots can trade trips with other pilots
on a voluntary basis (with some limitations) and pick up or
drop trips (with approval). The parties agree about this basic
process. They also agree that when a pilot is in the military,
his or her military service is involuntary.
    The parties disagree, however, about the level of control
that pilots have to schedule their military duty so that it does

13
   The district court’s conclusion that the purpose of military leave is to
promote pilots’ own individual interests in a “parallel career” makes
little sense when military leave is protected by USERRA, which
Congress enacted explicitly to encourage public service in the military.
See 38 U.S.C. § 4301.
                 CLARKSON V. ALASKA AIRLINES, INC.                       25

not conflict with their work schedules at the Airlines. The
Airlines contend that pilots have “tremendous” flexibility to
schedule their military service, citing the testimony of
Ronald Limes, Alaska’s Base Chief Pilot and former Air
Force reservist. 14 In his deposition, Mr. Limes explained
that as a commander in the reserves, he had “very little”
flexibility, but as a rank-and-file servicemember, he had
“tremendous” flexibility to schedule squadron trainings on
weekends. Clarkson maintains that pilots’ control over
military duty, especially duties beyond those squadron
trainings, is more limited. Pilots can work with their military
schedulers to resolve conflicts, but the ability to reschedule
military duty depends on many factors including the pilot’s
training requirements, military needs, and the availability of
opportunities to engage in specific kinds of training.
Clarkson also argues that many of the leaves at issue in this
case were unknown to pilots more than a few weeks in
advance, rendering pilots’ control over the scheduling
process irrelevant. In his deposition, Clarkson explained that
predetermined monthly military schedules would often
change with little notice. Only the drill weekends, which
were set annually by the governor, were unlikely to change.
    Given this factual record, the district court erred in
finding that “[t]o the extent there is any scheduling conflict,
pilots can . . . work with the bidding system and other pilots
to ensure their flight schedules for [the Airlines]

14
  The Airlines also argue that the “most pointed evidence” comes from
Captain James Meldrum, an Alaska pilot who refused to sign a
declaration stating: “Even if a pilot volunteers for military duty it is the
military, not the pilot, who dictates the time and duration of that leave.”
However, in his deposition, Captain Meldrum explained it is only his
“belief” that military pilots have control; he has never been in the
military himself.
26               CLARKSON V. ALASKA AIRLINES, INC.

accommodate their military leave schedules.” Clarkson,
2021 WL 2080199 at *8. The evidence shows that pilots can
try to trade shifts with other pilots and that pilots can try to
work with their military scheduler to rearrange their duty
periods. 15 A jury could reasonably conclude that because of
last minute assignments, pilots do not have enough control
over their schedules to prevent conflicts. A jury could also
find that pilots’ level of control over their military duty is
comparable to their level of control over other types of
leaves. For instance, pilots receive advance notice of jury
duty and have some flexibility to reschedule it. Pilots can
also use sick leave for pre-scheduled appointments or
procedures. These comparability determinations are for the
jury to make, not the court. 16

15
   USERRA’s legislative history addresses employees’ ability to
reschedule work, as reflected in the House Report on the bill that became
§ 4316(b)(1):

         [T]o the extent the employer policy or practice varies
         among various types of non-military leaves of
         absence, the most favorable treatment accorded any
         particular leave would also be accorded the military
         leave . . . . Thus, for example, an employer cannot
         require servicemembers to reschedule their work week
         because of a conflict with reserve or National Guard
         duty, unless all other employees who miss work are
         required to reschedule their work.

H.R. Rep. 103-65, pt. 1, at 33-34 (1993) (citations omitted); see also
Rogers, 392 F.3d at 767-68 (citing the House Report).
16
   Clarkson also argues that because military leave is involuntary, the
“control” factor must come out in his favor. Clarkson relies on
Waltermyer, which explained that military leave is comparable to jury
duty leave, bereavement leave, and sick leave because all such leaves
signaled “lack of choice by the employees.” 804 F.3d at 825. But, in
                 CLARKSON V. ALASKA AIRLINES, INC.                     27

                                 ***
    As explained above, the district court improperly
resolved factual disputes as to each factor in the
comparability analysis in order to grant summary judgment.
Comparability is fundamentally an issue for the jury, and
where reasonable jurors could return a verdict in favor of the
nonmoving party, factual disputes must be resolved by a
jury. See, e.g., Reynaga, 847 F.3d at 685 (citations omitted).
Here, Clarkson has presented persuasive evidence in support
of his claim. We therefore reverse the grant of summary
judgment and remand for further proceedings consistent
with this opinion.
    C. Pay During Leave
    Finally, the Airlines argue that “pay during leave” is not
a standalone benefit that they provide under their CBAs to
any employee on leave, rendering Clarkson’s claim moot
even if short-term military leave is comparable to another
type of leave. Because the district court found that military
leave was not comparable to any other leaves, it did not
address this issue and “decline[d] to adopt a specific
interpretation of the ‘rights and benefits’ definition.”
Clarkson, 2021 WL 2080199 at *3. Although our sister
circuits have addressed this issue, see Travers, 8 F.4th at
199; White, 987 F.3d at 619, we remand for the district court

Waltermyer, the court concluded that: “Particularly important is the fact
that the guardsmen have no individual voice in selecting the weeks they
will be on active duty.” Id. Here, the Airlines have presented evidence
to demonstrate that pilots may have some “voice in selecting” their
schedules. The governing regulation also clearly states that the factor to
consider is “the ability of the employee to choose when to take the
leave,” 20 C.F.R. § 1002.150(b), not whether the leave is voluntary.
28            CLARKSON V. ALASKA AIRLINES, INC.

to consider the “pay during leave” issue in the first instance.
                      CONCLUSION
    For the foregoing reasons, we reverse the district court’s
grant of summary judgment to the Airlines. On remand, the
district court should consider the “pay during leave” issue in
the first instance.
     REVERSED AND REMANDED.