United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                  ___________

                                  No. 03-1664
                                  ___________

Midwestern Machinery Co., Inc.; Brian  *
F. Gagan; Sharon Tolbert Glover;       *
Charles M. Koosmann; Laurie I.         *
Laner; Jack Reuler; Nigel Linden;      *
Daniel L. Jongeling; Industrial Rubber *
Products, Inc.; Daniel O. Burkes,      * Appeal from the United States
                                       * District Court for the District of
            Appellants,                * Minnesota.
                                       *
      v.                               *
                                       *
Northwest Airlines, Inc.,              *
                                       *
            Appellee.                  *
                                  ___________

                             Submitted: February 13, 2004
                                Filed: December 7, 2004
                                 ___________

Before MORRIS SHEPPARD ARNOLD, JOHN R. GIBSON, and RILEY, Circuit
      Judges.
                         ___________
MORRIS SHEPPARD ARNOLD, Circuit Judge.

       The plaintiffs (referred to collectively as Midwestern) appeal from a summary
judgment entered against them in their action against Northwest Airlines under § 7
of the Clayton Act, see 15 U.S.C. § 18. For the reasons stated below, we affirm the
judgment of the district court.1

                                         I.
       Northwest Airlines merged with Republic Airlines in 1986. Before the merger,
Northwest was the eighth largest airline in the United States, and Republic was the
ninth largest. Both had a significant presence at the Minneapolis-St. Paul Airport
(MSP). The merger was sanctioned by the Department of Transportation but was not
granted antitrust immunity.

       In 1997, eleven years after the merger, Midwestern filed suit claiming that the
merger violated § 7 of the Clayton Act. The district court dismissed the complaint,
holding that the merger could not be the subject of a § 7 claim because the acquired
entity's stock had ceased to exist. We reversed that dismissal in Midwestern
Machinery, Inc. v. Northwest Airlines, Inc., 

(8th Cir. 1999). On
remand, the district court allowed Midwestern to certify a class of plaintiffs, but
notification of the class was postponed while the district court considered Northwest's
motion for summary judgment on the ground that the statute of limitations had run.
When the district court granted the motion, Midwestern appealed.

      Section 7 of the Clayton Act prohibits acquisitions that serve "substantially to
lessen competition, or to tend to create a monopoly," 15 U.S.C. § 18, and contains a
four-year statute of limitations for private actions, 15 U.S.C. § 15b. Section 7 exists
primarily to arrest, at their incipiency, mergers that could produce anti-competitive

      1
       The Honorable Donovan W. Frank, United States District Judge for the
District of Minnesota.

                                         -2-
results. Concord Boat Corp. v. Brunswick Corp., 

, 1050 (8th Cir.
2000), cert. denied, 

(2000). Generally, a "Section 7 action challenging
the initial acquisition of another company's stocks or assets accrues at the time of the
merger or acquisition." 

however, that there are three
reasons why its suit, though it was filed eleven years after the merger, nevertheless
survives Northwest's motion for summary judgment on limitations grounds.
Midwestern also argues that its action is not barred by laches.

                                           II.
       Midwestern asserts first that Northwest's "continuing violations" of the Clayton
Act will allow it to avoid the bar of the statute of limitations. Specifically, it points
to Northwest's "hub premium" for flights through its MSP hub and Northwest's
actions to prevent successful entry into MSP by low-cost carriers as overt acts that
restart the statute.

       Under the so-called continuing-violation theory " 'each overt act that is part of
the violation and that injures the plaintiff ... starts the statutory period running again,
regardless of the plaintiff's knowledge of the alleged illegality at much earlier
times.' " Klehr v. A. O. Smith Corp., 

, 189 (1997) (quoting 2 P. Areeda
& H. Hovenkamp, Antitrust Law ¶ 338b (rev. ed. 1995)). Midwestern, however, cites
no appellate decisions applying this principle to § 7 claims. Rather, it attempts to
analogize this case to other areas of antitrust law where such a theory has in fact been
recognized.

      The typical antitrust continuing violation occurs in a price-fixing conspiracy,
actionable under § 1 of the Sherman Act, see 15 U.S.C. § 1, when conspirators
continue to meet to fine-tune their cartel agreement. See Pennsylvania Dental Ass'n
v. Medical Serv. Ass'n of Pa., 

, 278 (3d Cir. 1987), cert. denied, 

(1987). These meetings are overt acts that begin a new statute of limitations



                                           -3-
because they serve to further the objectives of the conspiracy. Cf. Zenith Radio Corp.
v. Hazeltine Research, 

, 338 (1971).

       But "[c]ontinuing violations have not been found outside the RICO or Sherman
Act conspiracy context ... because acts that 'simply reflect or implement a prior
refusal to deal or acts that are merely unabated inertial consequences (of a single act)
do not restart the statute of limitations.' " Concord 

(quoting
DXS, Inc. v. Siemens Med. Sys., Inc., 

, 467-68 (6th Cir. 1996) (citations
and internal quotations omitted)). In other words, to apply the continuing violation
theory to non-conspiratorial conduct, new overt acts must be more than the unabated
inertial consequences of the initial violation.

       Looking at how courts have applied the continuing violation theory to claims
brought under § 2 of the Sherman Act sheds light on why that theory does not apply
to Clayton Act claims. In Hanover Shoe, Inc. v. United Shoe Mach. Corp., 

, 483-84 (1968), United, a manufacturer and distributor of shoe machinery, was
sued by one of its customers, Hanover, for monopolizing the shoe machinery industry
in violation of § 2 of the Sherman Act. United leased but refused to sell its machinery
to Hanover, causing Hanover to pay more for use of the machines over time. United's
lease-only policy first adversely affected Hanover in 1912, but suit was not filed until
1955. The Court held that United's continued adherence to the policy was part of its
maintenance of its monopoly. The Court stated:

      We are not dealing with a violation which, if it occurs at all, must occur
      within some specific and limited time span. ... Rather, we are dealing
      with conduct which constituted a continuing violation of the Sherman
      Act and which inflicted continuing and accumulating harm on Hanover.
      Although Hanover could have sued in 1912 for the injury then being
      inflicted, it was equally entitled to sue in 1955.



                                          

n.15. The Court thus endorsed the Third Circuit's reasoning that
United's conduct "went beyond a mere continuation of the refusal to sell; it collected
rentals on leases and entered into new leases when old machinery was no longer in
working condition and required replacement." Hanover Shoe, Inc. v. United Shoe
Machinery Corp., 

, 794 (3d Cir. 1967), aff'd in part and rev'd in part,

(1968).

       While United engaged in a continuing violation by actively using the lease-
only policy to maintain its monopoly, cf. National Souvenir Ctr., Inc. v. Historic
Figures, Inc., 

, 513-14 (D.C. Cir. 1984), cert. denied, 

(1984), the statute of limitations begins to run from the initial violation where
defendants are accused of attempting to monopolize by passively implementing anti-
competitive policies, such as a refusal to deal, see Garelick v. Goerlich's, Inc.,

, 856 (6th Cir. 1963) (per curiam), or maintaining an action to enforce
a restrictive covenant, see Pace Indus. v. Three Phoenix Co., 

, 236-37
(9th Cir. 1987). Existing competitors must act when a rival initiates anti-competitive
policies that do not require additional anti-competitive action to implement. See 2 P.
Areeda & H. Hovenkamp, Antitrust Law ¶ 320c4 (2d ed. 2000). In such
circumstances, implementation is only a reaffirmation of the policy's adoption, and
the statute begins to run as soon as the competitor suffers injury. 

; see also Concord 

(citing 

).

       Only where the monopolist actively reinitiates the anti-competitive policy and
enjoys benefits from that action can the continuing violation theory apply. This
distinction between "new and independent act[s] [that] inflict new and accumulating
injury on the plaintiff" (which restart the statute of limitations), 

, and unabated inertial consequences of previous acts (which do not) allows the
statute of limitations to have effect and discourages private parties from sleeping on
their rights.



                                         -5-
       Applying this rationale to mergers makes no sense. If the initial violation was
the merger itself, none of the "continuing violations" Midwestern alleges can justify
restarting the statute of limitations because these acts were not undertaken to further
an illegal policy of merger or to maintain the merger. Otherwise, every business
decision could qualify as a continuing violation to restart the statute of limitations as
long as the firm continued to desire to be merged. Once the merger is completed, the
plan to merge is completed and no overt acts can be undertaken to further that plan.

       Unlike a conspiracy or the maintaining of a monopoly, a merger is a discrete
act, not an ongoing scheme. A continuing violation theory based on overt acts that
further the objectives of an antitrust conspiracy in violation of § 1 of the Sherman Act
or that are designed to promote a monopoly in violation of § 2 of that act cannot apply
to mergers under § 7 of the Clayton Act. Even if the initial merger violated § 7, it
makes little sense to hold that policies were pursued to effectuate the illegal merger
as we might in a case involving a conspiracy violating § 1 (e.g., cartel meetings
occurred to effectuate a price-fixing agreement) or a case violating § 2 (e.g., ongoing
policy of predatory pricing undertaken to effectuate monopolization). Once a merger
is completed, there is no continuing violation possible under § 7 that would justify
extending the statute of limitations beyond four years.

        Midwestern alleges that Northwest increased the hub premium for MSP and
prevented entry by low-cost carriers into MSP by changing prices and schedules and
offering rewards to passengers and travel agents. A continuing violation theory based
on these alleged overt acts, however, could not justify extending the statute even if
we believed that such a theory could ever apply to § 7. That is because, even if the
initial merger violated § 7, these allegations are not acts furthering the objectives of
the merger. They may be acts that violate other antitrust laws, but they are not
continuing violations of the Clayton Act sufficient to restart the statute of limitations.




                                           -6-
       Even if the merger itself was unlawful, the continued existence of the merged
entity is not a continuing violation: It is simply the natural unabated inertial
consequence of the merger. Conducting business is presupposed by the merger itself.
Selling goods and services and responding to potential competition by lowering
prices (aside from predatory pricing practices that may violate § 2 of the Sherman
Act) or increasing product quality are the very things that competitive firms, merged
or not, are encouraged to do to provide consumers with high quality products at the
lowest prices.

       Midwestern's theory would expose merged firms to potential liability in private
suits as long as the firm remained merged because, assuming that the initial merger
violated the Clayton Act, every subsequent action by the merged firm would be a
continuing violation designed to maintain the merged firm's viability. Merged
companies do face a higher susceptibility to private suits than non-merged firms, but
only for the four years following the merger, absent some other justification for
tolling the statute of limitations.

       Congress did not prohibit all mergers in the Clayton Act because to do so
would preclude the consumer benefits that mergers can generate. Admittedly, a pro-
competitive merger and an anti-competitive one are hard to discern from each other,
but exposing a firm to perpetual liability under the Clayton Act simply because its
business history includes a merger would chill pro-competitive business
combinations. Finding that a continuing violation theory does not apply to § 7 does
not give a "green light" to monopolists, as Midwestern claims, because merged firms,
like all firms, are still subject to the Sherman Act's prohibitions on monopolization
or attempts to monopolize.

      Finally, it is worth noting that because private suits under the antitrust laws are
allowed to correct public wrongs, it is appropriate to encourage suits as soon as
possible to stop (or at least compensate) harm to the public. Mergers occur in the

                                          -7-
public eye and at a reasonably certain date. It is undisputed that Midwestern was well
aware of its potential injury when Northwest and Republic merged. While a plaintiff
need not be unaware of an initial act's illegality for the continuing violation theory to
be available to extend the statute of limitations in a Sherman Act claim, it is worth
noting that, unlike mergers (including the Northwest-Republic merger), initial
violations of the Sherman Act usually occur in secret. In practice, where the plaintiff
had actual knowledge of the initial violation and suffered sufficient injury, courts
generally do not toll the statute of limitations based on a continuing violation theory.
2 P. Areeda & H. Hovenkamp, Antitrust Law ¶ 320c1 at 210-11 (2d ed. 2000).

                                          III.
      Midwestern's holding-and-use theory is more firmly rooted in precedent.
"Clayton Act claims are not limited to challenging the initial acquisition of stocks or
assets ... since 'holding as well as obtaining assets' is potentially violative of
section 7." Concord 

(quoting United States v. ITT Cont'l
Baking Co., 

, 240 (1975)). But since holding and using assets acquired
in a merger in the same manner as they were used at the time of the merger is merely
an unabated inertial consequence of the merger, Concord 

,
only different uses of assets can justify restarting the statute of limitations.
Midwestern relies on United States v. du Pont de Nemours & Co., 

(1957), and ITT to support its application of the holding-and-use theory in the present
circumstances.

       In du 

, 598-99, although the defendants had acquired a
twenty-three percent stock interest in General Motors by 1919, it was not until
decades later that du Pont's status as GM's supplier of automotive finishes and fabrics
threatened competition. There was no realistic threat of anti-competitive behavior at
the time of the acquisition. 

Since the government (unlike private
individuals) did not face a statute of limitations when it initiated action under the
Clayton Act, du Pont did not concern a statute of limitations issue; the case was about

                                          -8-
whether an acquisition that did not violate § 7 at the time that it occurred could be the
basis for a later suit. 

The Supreme Court held that the acquisition need
violate § 7 only at the time of the suit for the government to sue; it may bring an
"action at any time when a threat of the prohibited effects is evident." See 

in du Pont did not address the question of whether a merger that violated § 7
at the time that it occurred could be the basis of a private suit more than four years
after that merger based on the holding and use of acquired assets. The Court held
only that the theory could be sufficient for a government-initiated suit at the time that
competition was threatened. 

presented no evidence tending to show why it would not have
perceived Northwest's acquisition of Republic as anti-competitive in 1986. Nor has
it produced evidence that the anti-competitive threat appeared only after July 1993
(four years before it filed this suit). Unlike du Pont, it was clear at the time of the
merger here that the combination of Northwest and Republic could lessen
competition. In du Pont, there was no violation until decades later when GM became
a successful and dominant firm and du Pont's supply relationship with GM became
one based on stock ownership rather than competition among suppliers. That was not
the case here. Popular press accounts from 1986 show that it was well understood
that the merger of Northwest and Republic would produce increased concentration
at MSP.

       ITT is not useful to Midwestern because it, too, did not concern a statute of
limitations. In that case, ITT and the Federal Trade Commission had entered into a
consent order for ITT's alleged violations of the Clayton Act and the Federal Trade
Commission 

. The order prohibited ITT from acquiring any
other bakeries for ten years, and ITT violated the order. 

The case
before the Supreme Court concerned the amount of damages ITT owed for violating
the order. The Court interpreted "acquiring" as used in the consent order as
prohibiting ITT's continued holding of the bakeries acquired in violation of the order,

                                          -9-
and thus held that ITT was continually violating the order until the bakeries were
divested. In dicta, the Supreme Court stated that " 'acquisition' as used in § 7 of the
[Clayton] Act means holding as well as obtaining assets. ... [T]he framers of the Act
did not regard the terms 'acquire' and 'acquisition' as unambiguously banning only the
initial transaction of acquisition; rather they read the ban against 'acquisition' to
include a ban against holding certain assets." 

ITT, however, was not
about the statute of limitations but about penalties. ITT also concerned the authority
of the FTC, not private parties. 

can only assuredly be said to stand for
the proposition that, with respect to penalties for violations of consent orders, holding
prohibited assets (and not just obtaining them) continues to trigger penalties until the
violations of the consent order are corrected. 2 P. Areeda & H. Hovenkamp, Antitrust
Law ¶ 320c5 (2d ed. 2000).

       Even reading these cases broadly to support the applicability of the holding-
and-use theory to private § 7 claims, as Midwestern urges, the statute of limitations
must begin to run at some point in order for the time bar to have any effect and to
give repose to merged firms. If assets are used in a different manner from the way
that they were used when the initial acquisition occurred, and that new use injures the
plaintiff, he or she has four years from the time that the injury occurs to sue, see

; Zenith 

.

      Even assuming that the holding and use of assets can be a valid justification for
extending the statute of limitations in a private Clayton Act suit, Midwestern's
arguments fail because its assertion that market power acquired by Northwest via the
merger is such an asset is logically flawed.

       First, market power cannot be an asset for purposes of the Clayton Act if the
statute of limitations is to have any effect. Otherwise, the holding-and-use theory
would swallow the time bar. Market power is defined as "the ability of a firm ... to
raise price above the competitive level without losing so many sales so rapidly that

                                          -10-
the price increase is unprofitable and must be rescinded." William A. Landes &
Richard A. Posner, Market Power in Antitrust Cases, 94 Harv. L. Rev. 937, 937
(1981). All horizontal mergers lead to increased market share and, with that,
increased market power: Post-merger sales, even those made through market
domination, are not independent acts. They are merely reaffirmations of the original
merger. Horizontal mergers, by definition, increase the size and enhance the market
power of the resulting firm. "Section 7 of the Clayton Act ... requires proof of market
power; in fact, the main purpose of section 7 is to limit mergers that increase market
power." 

If market power could be considered an asset the
retention of which violated the Clayton Act and required extending the statute of
limitations until the market power asset was disgorged (ignoring the impossibility of
divesting a firm of only its market power), the statute of limitations would have no
effect. By definition, any merger that created market power would violate the
Clayton Act forever as long as the firm maintained its market position. Additionally,
market power, unlike other assets under the Clayton Act, cannot be traded, sold, or
bought absent the trade, sale, or purchase of other assets. Market power is not itself
an asset, but is the result of combinations of other assets that the firm holds.

        Second, even if market power could be considered an asset, it was not
exchanged in the merger; rather, the merger created the market power. The holding-
and-use theory allows a statute of limitations to be tolled only when an asset is used
differently after a merger from the way that it was being used before a merger. If the
asset did not exist before the merger, logic requires that this theory cannot apply. If
market power could be an acquired asset for Clayton Act purposes, so would
economies of scale and other size efficiencies gained from the combination of two
firms in a merger. To hold that the holding-and-use theory operated for these
"assets," however, would subject even the most pro-competitive mergers to perpetual
liability. This cannot be.




                                         -11-
       Even if we consider market power to be an asset that was exchanged in the
merger, rather than being created by it, there is no evidence in this case that it is being
used differently. Midwestern asserts that Northwest's business strategy changed
significantly in the last half of 1993. The evidence presented and the experts' reports,
however, do not support that assertion. Some of the experts looked only at
Northwest's activity after the suit was filed in 1993, and others did not show any
difference between Northwest's use of market power before the merger and beginning
in 1993. In order to toll the statute of limitations based on holding and using market
power, Midwestern must demonstrate at what point it was first injured by Northwest's
differing use of market power. It is at that point that the statute of limitations begins
to run. It has not done that; it merely asserts a change.

       It is clear law that a nonmovant cannot survive a summary judgment motion
merely by resting on its pleadings as Midwestern attempts to do here. Discovery in
this case was sufficient for Midwestern to provide evidence, if it exists, that
Northwest's use of market power changed. Three time periods are of relevance here:
the pre-merger period; 1986 (the year of the merger) to 1993 (four years before suit
was filed); and 1993 to the present. To prevail against Northwest's summary
judgment motion on the basis of the holding-and-use theory, Midwestern must show
that Northwest's use of market power during the first two periods was the same while
only during the third period was the market power used in a new fashion.
Midwestern, however, has provided no information about Northwest's use of market
power before the merger. Without this information, we cannot know whether its post-
1993 use of market power differed significantly from its pre-merger use.

      Midwestern also suggests that market innovations such as the pricing program
that Northwest employed after 1993 exemplify its different use of market power.
Such a theory, however, would preclude merged firms from responding to changes
in market conditions and opportunities. This makes scant sense.



                                           -12-
       Midwestern's briefs note that the holding-and-use theory is related to their
continuing violation theory, while Northwest's briefs argue that the two theories are
the same. While both theories, if accepted for § 7 actions, would allow a private
litigant to sue more than four years after the initial acquisition, we suggest that both
parties are incorrect. Under the holding-and-use theory, the claim must arise from an
injury different from the injury caused by the initial acquisition. Where the injury was
sustained at the time of the acquisition, "the limitations period ... cannot be extended
on the basis of the holding and use of the acquisitions." Concord 

. In contrast, a continuing violation theory is based on an initial action that
violates the antitrust laws followed by injuries caused by illegal actions designed to
implement and effectuate the initial violation. Holding and using assets restarts the
statute of limitations only when the use of the assets differs after the merger, while
continuing violations restart the statute of limitations when there is an ongoing
scheme, such as a price-fixing conspiracy or an attempt to monopolize.

                                           IV.
      "The limitations period ... starts to run at 'the point the act first causes injury.' "
Concord 

(quoting 

). "The statute
can be tolled under certain circumstances, such as ... where a plaintiff's damages are
only speculative during the limitations period." Concord 

.

       Midwestern argues that the statute of limitations should be tolled here because
the plaintiffs' future damages were speculative during the initial limitations period
ending in 1990. In Zenith 

-42, the Supreme Court tolled the
statute of limitations in a Sherman Act case because if suit had been filed during the
limitations period the existence of the claimant's future damages would have been
speculative because they would have been based on a hypothetically free market and
on the market share that the claimant would have enjoyed were it not for a conspiracy
among its competitors. The Court stated that "refusal to award future profits as too
speculative is equivalent to holding that no cause of action has yet accrued ... In these

                                            -13-
instances, the cause of action for future damages, if they ever occur, will accrue only
on the date they are suffered." 

The plaintiffs in Zenith Radio could not
have avoided incurring the future damages even if they had filed suit during the
limitations period.

       Midwestern does not claim that if it had filed suit within the four-year statute
of limitations period it could not have calculated any of the damages that it had
suffered. Instead, it argues that it should be allowed to restart the statute of
limitations because it could not forecast future damages at that time. In 1990,
Midwestern could have established its injury but could not have precisely calculated
the scope and extent of the future damages it would suffer due to the Northwest-
Republic merger. If it had filed suit by 1990 and won equitable relief on the merits,
however, it would have incurred no future damages. Unlike the plaintiffs in Zenith
Radio, Midwestern could have precluded future damages from occurring by obtaining
within four years of the merger the injunctive relief that it now seeks or possibly
divestiture.

       Injuries caused by a merger, of course, might not materialize until after the
four-year limitation period has expired. In that case, the plaintiff has not been injured
yet, and the statute of limitations does not begin to run until the plaintiff suffers
injury. See Concord 

. But where the plaintiff's injury is
immediate (as Midwestern's was according to the class representatives) the statute of
limitations begins to run at that time. The limitations period begins when "present or
future damages became definite enough to support a recovery." 2 P. Areeda &
H. Hovenkamp, Antitrust Law ¶ 320d (2d ed. 2000). The total extent of the alleged
damages, including future damages, was unknown at that time, but damages that
could be claimed existed. Midwestern, had it filed suit during the four years
following the merger, would have been able to recover the damages it had already
suffered if the court found that Northwest's merger with Republic violated the
Clayton Act. The scope and extent of Midwestern's future damages may have been

                                          -14-
speculative, but the fact that it had suffered a quantifiable injury was not. See 

(analyzing Zenith Radio).

       Refusing to extend the statute of limitations in this case ensures that the statute
continues to have meaning. We cannot imagine a Clayton Act claim (which means,
by definition, that the plaintiffs allege that an acquisition has lessened competition
and injured them) that could not be filed more than four years after the acquisition
were we to hold that the unascertainable scope and extent of future damages was
sufficient to warrant tolling the statute. In merger cases where monopolization by the
merged firm is intimated, as it was here, future damages to be borne by consumers
will always be speculative as long as the merged firm exists.

       This holding does not mean, however, that Midwestern was without recourse
for damages that it suffered after 1990. If, in an action filed within the statute of
limitations period, Midwestern had proved antitrust injury stemming from the alleged
Clayton Act violation, the court could have provided Midwestern with equitable relief
that would have precluded the post-1990 damages, including the damages that it now
seeks. And if Northwest's actions constituted violations of other antitrust laws, such
as § 2 of the Sherman Act, Midwestern would have had a new and separate cause of
action with a four-year statute of limitations from the time that the allegedly illegal
activity occurred.

                                         V.
       In addition to seeking damages, Midwestern sought injunctive relief. See
15 U.S.C. § 26. It asked the court to order changes in Northwest's policies at MSP,
including limiting the number of gates leased by Northwest, requiring Northwest to
provide equipment and services to low-cost carriers, requiring Northwest to establish
or allow interline or "code sharing" relationships with low-cost carriers (allowing
low-cost carriers to sell seats on Northwest's regional feeder airlines), limiting the
extent to which Northwest could engage in short-term profit-sacrificing activities,

                                          -15-
requiring Northwest to adjust its frequent flyer program, and requiring Northwest to
adjust its travel agent compensation program.

        Northwest, as part of its summary judgment motion, asserted that the equitable
relief sought was barred by the doctrine of laches, which requires a showing that the
plaintiff was "guilty of unreasonable and inexcusable delay that has resulted in
prejudice to the defendant." Goodman v. McDonnell Douglas, Corp., 

,
804 (8th Cir. 1979); cf. IT&T v. General Tel. & Elec. Corp., 

, 926-27
(9th Cir. 1975), overruled on other grounds, California v. American Stores Co., 

(1990). "The doctrine of laches is premised upon the same principles that
underlie statutes of limitations: the desire to avoid unfairness that can result from the
prosecution of stale claims." 

. Whether a statute of
limitations would bar a comparable action at law is one consideration in "determining
whether the length of delay was unreasonable and whether the potential for prejudice
was great," 

have already held, of course, that Midwestern's damages
claims are barred by the four-year statute of limitations.

       In addition, Midwestern produced no reasonable justification for the eleven-
year delay in filing suit. Northwest did nothing to conceal the merger from
Midwestern or to dissuade it from filing suit in a timely manner. Class
representatives stated that, during the four years following the much-publicized
merger, they did not file suit because they were too busy, too concerned about the
costs of litigation, or ignorant about their cause of action. If these reasons were
sufficient to justify denying a laches defense when the comparable statute of
limitations time period has run more than twice over, the notion of laches would be
rendered meaningless.

      Beyond the long-since expired statute of limitations in this case and the lack
of a justification from Midwestern to explain the delay, Northwest would be
substantially prejudiced were equitable relief to be granted at this late date. In 1989,

                                          -16-
Northwest's corporate parent ceased to be a public corporation and became a
privately-held company. In 1994 (after the four-year statute of limitations on the
merger had run), the corporation again became publicly traded. The current
shareholders of Northwest who invested in 1994 or after had no reason to believe that
a merger occurring more than seven years earlier could be the basis for suit.
Northwest's shareholders would be unduly prejudiced were this claim for equitable
relief allowed to proceed.

       Midwestern slumbered on its rights, and its equitable claims are now barred.
As stated before, however, if Northwest is violating other antitrust statutes through
its current practices, Midwestern could seek the same injunctive relief to remedy
those violations as it seeks here. In fact, the equitable relief sought here would find
a more hospitable home in a suit for a violation of § 2 of the Sherman Act than in an
action for a violation of § 7 of the Clayton Act, in which the usual remedy is the
divestiture of acquired stock or assets.

                                          VI.
       If, following its merger with Republic Airlines, Northwest has acted in a
predatory manner, it could be liable under the Sherman Act. We are loath, however,
to expose merged companies forever to private litigation under the Clayton Act,
which, as Midwestern admits, presents a lower threshold for liability than does the
Sherman Act. Non-merged competitors would not be susceptible to these suits. And
given that Congress has implicitly sanctioned merger activities where merged firms
are believed to promote economic efficiency, opening up the statute of limitations for
merged firms forever based solely on the potential effects that they may have on
competition would overly burden these firms. The four-year statute of limitations is
designed to allow private parties to assess whether the new merged firm is actually
enhancing efficiency or lessening competition. After that period, without some other
evidence of a different use of assets acquired from the merger, the Clayton Act's
statute of limitations has run, and the only private antitrust actions that remain will

                                         -17-
lie under the Sherman Act, the same vehicle open to potential suits against all firms,
merged or not.

      We therefore affirm the judgment of the district court.

JOHN R. GIBSON, Circuit Judge, dissenting.

        Midwestern Machinery contends that, beginning in the second half of 1993,
Northwest deliberately and dramatically changed its use of a key asset (or bundle of
assets) it obtained from Republic–its Minneapolis hub–and began to exploit that asset
to lessen competition in a way that injured Midwestern Machinery. Both the district
court and this Court have disposed of a factual issue, supported by expert reports,
independent studies, and statistical evidence, on summary judgment. Neither court
fulfills the duty to judge a summary judgment motion “viewing the evidence and
drawing all inferences in the light most favorable to the party opposing the motion.”
See Viking Supply v. Nat'l Cart Co., 

, 1096 (8th Cir. 2002).
Accordingly, I respectfully dissent.

       The district court disposed of Midwestern Machinery’s hub exploitation
argument in one sentence: “Specifically, Plaintiffs assert that the 1993 spike in
Northwest’s hub fare premium constitutes a new overt act of anti-competition;
however, Plaintiff’s own experts point to a number of factors that might have
contributed to the increase in hub fare premiums, none of which involves new or
different uses of the merger assets.” Slip op. at 5 (emphasis added). The Court today
devotes three sentences to the hub exploitation argument: “Midwestern also suggests
that market innovations such as the pricing program that Northwest employed after
1993 exemplify its different use of market power. Such a theory, however, would
preclude merged firms from responding to changes in market conditions and
opportunities. This makes scant sense.” Supra at 12.



                                        -18-
       Both the district court and this Court thus resolved the hub exploitation
argument without addressing the considerable body of evidence supporting
Midwestern Machinery's assertions. The district court did so by requiring the
plaintiff’s evidence to rule out the existence of influences which might have
contributed to the change in prices that experts and independent scholars say resulted
from Northwest’s exploitation of the “fortress hub” it acquired in the merger. Our
Court does so by a naked policy judgment–that punishing firms for responding to
changes in market conditions and opportunities is intolerable–apparently without
regard to whether such responses violate the Clayton Act.

       Midwestern Machinery's experts arrayed evidence that would allow a finder of
fact to arrive at the following conclusions:
       (1) Before the merger with Republic, Northwest did not have dominance over
the Minneapolis airport, but competed with Republic.2




      2
          The expert report of John C. Beyer concerning statute of limitations issues
stated:

      Before their merger, Northwest and Republic were, respectively, the
      eighth and ninth largest airlines in the United States. Both firms had
      substantial operations at the Minneapolis/ St. Paul airport (“MSP”) and
      were, by far, the largest airlines serving MSP. The firms competed with
      one another for passengers on the routes in which they overlapped.
      And, each firm constrained the ability of the other to charge
      supracompetitive prices on the routes in which they did not overlap
      because each could readily adjust their flight schedules and operations
      to take advantage of a profit opportunity on city-pair routes they were
      not serving at the time.

App. 20.

                                         -19-
       (2) After the merger, the new Northwest controlled around 75% of the gates
at the Minneapolis airport,3 carried 79% of Minneapolis passengers,4 and became the
only carrier serving 19 routes out of Minneapolis.5
       (3) Market power results from a highly concentrated market or high market
share, combined with barriers to entry of that market by competitors.6
       (4) Control of airport gates is an important entry barrier to new entrants at
some airports, and in particular, at the Minneapolis airport.7


      3
        At the time of the merger, the financial press reported that the merger would
result in Northwest controlling 75-80% of the gates at Minneapolis. Lee A. Ohanian
Report, App. 157. See also General Accounting Office, Airline Deregulation:
Barriers to Entry Continue to Limit Competition in Several Key Domestic Markets
10 (Oct. 18, 1996) (showing 49 out of 65 gates at Minneapolis had been leased to
Northwest).
      4
       Minnesota Planning, Flight Plan: Airline Competition in Minnesota 3 (1999).
      5
       Ohanian Report, App. 156-57 (quoting Dep't of Justice Report: “In 19 of [the
26 markets out of Minneapolis where Northwest and Republic provided most of the
service] the merger would consolidate the only two airlines providing nonstop
service, thereby eliminating all present competition.”).
      6
        Beyer Report, App. 22 (“Where a concentrated market is coupled with barriers
to entry . . . one can infer the possession of market power by the dominant firm.”);
Ohanian Report, App. 152 (“Market power requires a high market share and barriers
to entry into the market.”).
      7
        Beyer Report, App. 22; General Accounting Office, Airline Deregulation:
Barriers to 

(senior management at many start-up airlines said
long-term, exclusive gate leases are barrier to entry at Minneapolis; showing 49 out
of 65 gates at Minneapolis had been leased to Northwest; “The airports in Detroit,
Newark, and Minneapolis were most frequently cited by the airlines that started after
deregulation as having competition limited by constraints in gaining access to gates”;
requirement of subleasing gates to gain entry to Minneapolis was “key factor” in
Southwest's decision not to serve Minneapolis); Ohanian Report, App. 153 (“A key
barrier to entry in the airline market is access to gates.”). A General Accounting

                                        -20-
       (5) Possession of a “fortress hub” dominated by one carrier8 can create an entry
barrier by giving the dominant carrier a frequency-of-flights advantage that puts new
entrants at a competitive disadvantage9 and by locking in customers and travel agents
through frequent flyer and “frequent booker” programs.10
       (6) General economic conditions and Northwest's own financial situation
prevented it from effectively exploiting its market power until 1993.11
       (7) Beginning in the second half of 1993, there was a great leap in Northwest's
exploitation of its market power at Minneapolis, as demonstrated by its greatly




Office report from 1999 stated that all gates at Minneapolis were subject to exclusive-
use leases and that Northwest leased 54 of the 70 gates; airport officials stated that
there were “no gates available” to new entrants. General Accounting Office, Airline
Dergulation: Changes in Airfares, Service Quality, and Barriers to Entry 17 (March
4, 1999). See also Minnesota 

(“The U.S. General Accounting
Office found in 1996 that long-term, exclusive-use gate leases seriously inhibit
competition at Minneapolis-St. Paul. At airports where most gates are tied up in such
leases, new entrants are often forced to sublease gates, which usually results in gate
access at less desirable times and higher cost.”)
      8
      The term “fortress hub” is used in the airline industry to describe hubs in
which one carrier has a dominant share of flights or services. John S. Strong Report,
App. 202 n.8.
      9
        “[S]tudies have shown that a carrier with a frequency advantage in a market
gains a disparate share of local traffic, which compounds the competitive problem for
other carriers that compete at the network hub. When carriers with similar cost
characteristics do not have access to the same traffic flows, they are unable to
compete.” Department of Transportation, Office of Aviation and International
Economics, The Low Cost Airline Service Revolution 27 (April 1996).
      10
          Severin Borenstein, Hub Dominance and Pricing 4-5 (1999).
      11
          Ohanian Report, App. 170-71; Ohanian Rebuttal Report, App. 194-95.

                                         -21-
increased supra-competitive profit margins or “hub premiums.”12 This increase in
premiums corresponded with a new strategy by Northwest to reduce the sphere in
which it competed and concentrate on its fortress hubs.13
      (8) Also beginning in 1993, Northwest responded to a new problem–the
upsurge of low-fare new entrant airlines–by various strategies that involved
exploitation of its fortress hub at Minneapolis.14

       These propositions, which are supported by expert opinions backed up by data
and academic and governmental studies, suffice to show that beginning within the
four-year limitations period, Northwest made a new use of assets gained in the merger
to stifle competition and reap monopoly profits. Midwestern Machinery's claim

      12
          Beyer Report, App. 26-27 (“The increase in Northwest's [Minneapolis] hub
premium from 21 percent in 1993 to 46 percent in 1994 is substantial. . . . The
substantial increase in Northwest's [Minneapolis] hub premium between 1993 and
1994 indicates that Northwest changed the way in which it was exercising its
monopoly power. . . . Northwest's [Minneapolis] hub premium increased so
significantly because Northwest appears to have changed the way in which seats on
its airplanes were allocated amongst the various fare classes.”); Ohanian Report, App.
166 (contrasting fare premium charged by Northwest on Minneapolis flights in 1993
(21%) with that charged in 1994-97 (40.3%)).; Dep't of Transportation, Low Cost
Airline 

(comparing hub fare premiums at Minneapolis for
1988 (23%) and for 1995 (40.8%)); Ohanian Report, App. 169 (showing that
Northwest's profit margin for twenty major Minneapolis markets went from 0.9% in
the first quarter of 1993 to 15.5% in 1994-97); “[B]y the third quarter of 1998,
travelers using [the Minneapolis] airport were paying the third highest fares in the
nation.” Paul Stephen Dempsey, Predatory Practices and Monopolization in the
Airline Industry: A Case Study of Minneapolis/ St. Paul, 29 Transp. L. J. 129, 131
(2000). But cf. Minnesota 

(“Borenstein's analysis shows that
fare premiums paid by Northwest customers in Minneapolis-St. Paul increased
dramatically between 1989 and 1990, and have remained high since then.”).
      13
        See discussion infra at 8-9.
      14
        Strong Report, App. 201-38, discussed in detail, infra, at n.25.

                                        -22-
should survive summary judgment under the Clayton Act standards articulated in an
earlier stage of this case, Midwestern Machinery, Inc. v. Northwest Airlines, Inc., 

, 442-43 (8th Cir. 1999), and in Concord Boat Corp. v. Brunswick Corp., 

, 1050-51 (8th Cir. 2000).

       The Court today does not repudiate or gainsay the legal standards set out in
Midwestern Machinery and Concord Boat, that a cause of action for holding and use
of merger assets accrues when the threat of restraint or monopoly first becomes
evident and the plaintiff suffers injury thereby. Midwestern 

; Concord 

. The Court states, “[O]nly different uses of
assets can justify restarting the statute of limitations.” Supra at 8.15 Accordingly, I
have no need to argue about legal standards. Instead, my concern is with the Court's
treatment of the facts. The Court says that plaintiffs did not adduce evidence of the
facts alleged. In particular, the Court says that the plaintiffs did not show that they
used assets gained in the merger to threaten competition and that they did not show
they used the assets differently during the limitations period (1993 and after) than
they did during the preceding, time-barred period. The Court can only reach these
conclusions by ignoring a great deal of evidence to the contrary.




      15
         Compare II Phillip Areeda, Herbert Hovencamp, & Roger Blair, Antitrust
Law § 320c5 (2d ed. 2000) (“[A] continuing violation occurs when the defendant uses
the merger in a way that is not inherent in the acquisition itself. For example,
suppose that a merger gave a firm the structural power to engage in predatory pricing.
A damages action challenging such a merger would fail as long as predation were
merely possible or even likely. As a result, the statute of limitation would not run on
such a damage claim. However, once unlawful predation began and the plaintiff
could show the merger facilitated the predation, then the statute of limitation would
not bar a challenge to the merger itself . . .”). Whether the distinctive use is referred
to as a continuing violation or different holding and use, the idea is the same.

                                          -23-
       First, the Court says that market power is not an asset, but the result of
possession of other assets. Supra at 11. Northwest's experts did opine that Northwest
gained market power as a result of the merger, but they made it clear that the market
power came from assets acquired in the merger, such as Republic's gate leases at the
Minneapolis airport.16 When the plaintiffs' economists use the term “market power”
in this case, they use it as a proxy for the constellation of assets such as gate leases
that make up a “fortress hub.” Therefore, we need not worry about whether market
power is itself an asset, since it results from control of property and rights that are
indubitably assets. The Court's point goes only to the words used, not to the
substance of what the plaintiffs' evidence showed.

       Second, the Court says that the plaintiffs did not show that they made a
distinctive use of the assets during the limitations period that differed from their use
of the assets during the time-barred period. But the plaintiffs did show this. The
plaintiffs introduced evidence that Northwest's use of the Minneapolis hub varied in
three time periods. Because this case was decided on summary judgment, I will
recount the evidence in the light most favorable to the plaintiffs.

     Before the merger, Northwest did not control a majority of the gates at
Minneapolis or the flights arriving and departing from there. Before the merger,
Northwest was not able to charge a premium above the competitive price for
Minneapolis flights, because it had to compete with Republic.17




      16
        Ohanian Report, App. 152-55; Strong Report, App. 237 (“The hub dominance
and corresponding market power was firmly established by 1994 . . . .”).
      17
        See footnote 

.

                                         -24-
       Upon acquiring Republic, Northwest gained a dominant position at the
Minneapolis airport.18 In the period between the merger and 1994, Northwest did
charge a premium (above the weighted national average price) for Minneapolis
flights, but it was a relatively small premium.19 A plaintiff's expert explained that
factors such as the 1991-1992 recession and Northwest's own financial difficulties
prevented Northwest from making effective use of its control of the Minneapolis hub
to extract a large monopoly premium there.20

       Beginning in June 1993, Northwest responded to new developments, in part by
using the Minneapolis hub it gained in the merger. Several conditions combined to
allow this new use of the Minneapolis hub.

      First, it took some time after airline deregulation for experience to accrue
demonstrating the competitive advantages for an airline of dominating a hub airport.
The Northwest-Republic merger was part of a wave of airline mergers in the 1980's.
The Northwest-Republic merger was allowed by the Department of Transportation,
over Department of Justice protest, because the DOT believed in the theory of
“contestability”–that new carriers could easily enter new markets and therefore the
specter of competition would discipline dominant carriers.21 As history unfolded, the


      18
        Northwest Airlines, as a result of its acquisition of Republic Airlines in 1986,
was able to establish and sustain a service network that includes dominant hub
airports at Minneapolis-St. Paul (MSP), Detroit Metro Wayne County (DTW), and
Memphis (MEM).” Strong Report, App. 200.
      19
       Ohanian Report, App. 166-67 (citing two reports: one comparing 21%
premium in 1993 to 40.3% premium in 1994-97; and the other comparing premium
of 23% in 1988 to figures of 41% and 44% in 1995 and 1997, respectively).
      20
        hanian Report, App. 170.
      21
        

(“The DOT's highly permissive policies with
respect to mergers led to an explosion of such activity. . . . Many of these mergers

                                         -25-
theory was disproved.22 Michael E. Levine, of the Yale School of Management,
wrote an influential article in 1987 concluding that hubs were important sources of
competitive advantage for airlines and describing means by which airlines with strong
hubs exploited that advantage. See Michael E. Levine, “Airline Competition in
Deregulated Markets: Theory, Firm Strategy, and Public Policy,” 4 Yale Journal of
Regulation 393 (1987). Northwest hired Levine in 1992 as Executive Vice President
for Marketing. Levine determined that Northwest should abandon its previous
strategy of competing with the three biggest airlines on their own turf and concentrate
on reaping the advantages of Northwest's existing strong hubs. Davis Dyer and Len
Schlesinger, “Northwest Airlines: Coping with Change," Harvard Business School,
No. 9-897-027 at 10 (1997).

       Second, the industry developed new yield management systems that allowed
airlines to monitor ticket sales and instantly respond to exploit particular market
opportunities. In 1994, Northwest put in place newly developed yield management
computer systems which allowed Northwest to manipulate pricing on threatened



were approved under the then-prevailing (and since discredited) neo-classical
economics view that 'contestability' of markets would arrest any anticompetitive
conduct. The Northwest-Republic and TWA-Ozark mergers were vigorously
opposed by the U.S. Department of Justice [DOJ] on grounds that they would create
hub monopolies at Minneapolis and St. Louis, respectively.”).
      22
        Proponents of deregulation believed that airline markets were
      “contestable,” that is, new carriers could easily enter markets because
      airlines' key resources–airplanes–are highly mobile. As it turns out,
      however, other equipment and facilities needed to serve a
      route–especially gate space–can be difficult and costly to obtain.
      Facilities may also be limited for ticketing, baggage handling, operations
      and maintenance.

Minnesota 

.

                                         -26-
routes by offering more seats at already-established low fares, thus responding to new
entrants without sparking a general price war.23

       Third, a new type of airline entered the picture. “In the wake of the economic
recovery from the Gulf War recession, the U.S. airline industry in 1993-94
experienced a significant upsurge in applications and entry by low-fare new entrant
airlines, typically operating with lower costs and offering service at significantly
lower fares than the major network airlines.”24 Where such airlines were able to
establish routes at a hub, hub premiums collected by the dominant carrier declined.25

      In response to this new threat, Northwest used its control of the Minneapolis
hub to chase out low-fare entrants by price cuts focused on the entrant's routes and
by swamping the challenged routes with flights and seats.26 Northwest's size

      23
         Strong Report, App. 208-10, 218. Cf. 

(“The complex
fare structures with computerized capacity controls which have come to dominate the
industry play an important role in these competitive tactics.”).
      24
        Strong Report, App. 201; Dep't of Transportation, Office of Aviation and
International Affairs, The Low Cost Airline Service Revolution 3 (April 1996)
(“[S]ince early1993, the pace of this major evolutionary development [the “advent of
low-cost carriers”] has dramatically quickened.”).
      25
        Strong Report, App. 216-17.
      26
        A specific pattern of anticompetitive behavior began to be apparent in
      1993-94 and continued thereafter. These practices include capacity
      “dumping” of low fare seats and flight frequencies, “bracketing” of
      flights, restrictive controls over gates at its fortress hub airports, targeted
      frequent flyer and travel agent incentive programs. These practices
      serve to make sustained competition much more difficult for low-fare
      carriers, especially new entrants who do not have the size or network
      operations of Northwest or the financial resources to withstand
      prolonged periods of such anticompetitive behavior.


                                           -27-
advantage over the entrants, which obviously resulted in part from the merger, gave
Northwest the financial staying power to engage in targeted price cuts so that the new
entrants could not sustain a pricing advantage or even price parity.27 Using the
sophisticated yield management systems now available, Northwest could focus price
responses on the particular routes challenged without sparking an industry-wide price
war.28 In at least one case, Northwest cut fares on the challenged routes below
variable cost until the new entrant gave up the route.29 Facilities and equipment
gained during the merger30 gave Northwest the capacity to swamp the market with


Strong Report, App. 203 (footnote omitted). Strong's list of Northwest's techniques
to drive new entrants out of the market included some actions that were directly
dependent on controlling facilities at Minneapolis (“Restrictions on gates or facilities
(e.g., counters, operations offices) that prevent a new entrant from being able to
launch competing service”) and others that capitalize on Northwest's ability to offer
more flights (“Scheduling departures in close proximity to the new entrant's flights,
known as 'bracketing.'”). This technique was described in an article by Michael
Levine: “Add frequency where possible, to 'sandwich' the new entrant's departures
between one's own departures.” 

.
      27
         Strong Report, App. 218-20 (“As a major airline, Northwest's ability to
sustain such revenue losses is likely to be much greater than a smaller entering
carrier.”). Cf. 

(“The object is to reduce trial and to subject the
new entrant to a prolonged period of operation at low load factors. This strategy saps
the entrant's working capital . . . .”).
      28
        Strong Report, App. 218.
      29
      E.g., Strong Report, App. 223-24 (during time Vanguard Airlines competed
on Minneapolis-Des Moines route, Northwest charged prices below variable cost).
      30
        Although Midwest has not pointed to much specific evidence of what
particular Republic assets were used, the record does contain evidence that would
allow a finder of fact to conclude that, for instance, Northwest implemented its new
strategies using Republic's DC-9's and gates gained in the merger. Beyer Report,
App. 22 (Northwest controlled approximately 75% of gates at Minneapolis after
merger); Richard Ihrig Affidavit, App. 7-9 (summarizing evidence that DC-9 aircraft

                                         -28-
flights and seats,31 so that the new entrants could not offer any scheduling advantage
to travelers. Once the new entrant had been chased out of town, Northwest cut back
its flights and raised its fares above the level where they had been before the new
entrant's challenge.32

       The plaintiffs came forward with evidence that only within the limitations
period did Northwest gain the knowledge, the technology, and the market conditions
that allowed it to exploit the market power the Republic merger placed in its grasp.
I cannot concur in affirming summary judgment on such a record.
                        ______________________________




gained in merger were used to add flights on challenged routes).
      31
        Strong Report, App. 221-22 (generally), 225 (when Vanguard entered Kansas
City-Minneapolis market, Northwest increased number of flights on the route by 48%
and number of seats by 53%); 230-31 (when Sun Country Airlines entered
Minneapolis market, Northwest added 33% to seat capacity of challenged routes in
two years, whereas rate of growth for previous five years was 1%; increase was
almost five times the number of seats offered by Sun Country on route); cf. 

(“If circumstances (including the financial condition of the new entrant)
warrant, the incumbent can flood the market with low-priced seats, withdrawing them
almost invisibly at peak times or as competitive conditions allow.”).
      32
       Strong Report, App. 223-24 (Vanguard airlines); 232 (after Kiwi International
was forced from Minneapolis-Detroit market, Northwest changed fare from $69 to
$467).

                                         -29-