Indiana Gas Co. and Citizens Gas & Coke, two utilities that supply natural gas to customers in Indiana, formed a joint venture (called ProLiance Energy) to manage the contracts by which they purchase gas and transportation services from the interstate pipelines that pass through that state. United States Gypsum (USG) purchases substantial quantities of gas for use in manufacturing; it buys gas at the wellhead and deals directly with the pipelines for transportation. In this litigation under sections 1 and 2 of the Sherman Act, 15 U.S.C. §§ 1, 2, USG contends that ProLiance is an unlawful combination that by contract controls a substantial fraction of the transport capacity between the gas fields and Indiana, and that it has used this market power to monopolize. Even though USG buys transportation directly from the pipelines, it alleges, the price the pipelines can charge for their services depends on what ProLiance has done with its portion of the capacity. According to USG, pipelines have been able to charge more for their residual capacity because of ProLiance’s existence (and practices) than the pipelines would have been able to charge in its absence.
Indiana Gas and Citizens Gas have many customers with firm entitlements to gas. In order to assure delivery, Indiana Gas and Citizens Gas purchase more pipeline *574 capacity than needed for daily deliveries; they hold the excess as reserve for the benefit of the uninterruptible customers during periods of peak demand, such as cold snaps or a business’s high season. During times of average demand, Indiana Gas and Citizens Gas sold their excess transport entitlement on the spot market, where USG bought it at attractive prices and used it to secure gas that it stored for times when spot market prices were high. After ProLiance came into existence, however, it ended (or at least greatly curtailed) these spot-market sales, forcing USG to pay more for firm capacity from the pipelines (firm commitments always sell for more than interruptible or spot purchases).
There are several ways to characterize what happened. ProLiance contends that, by managing purchases on behalf of both Indiana Gas and Citizens Gas, it has achieved efficiencies: when one utility’s demand peaks, the other’s may be closer to normal, which means that less aggregate reserve capacity is needed. This is the way in which an insurer, by pooling many imperfectly correlated risks, creates a portfolio that is less risky than any insured standing alone. Thus ProLiance needs less standby capacity for peak periods and can provide more firm, uninter-ruptible commitments per unit of pipeline capacity than either Indiana Gas or Citizens Gas could do on its own. An increase in demand from the utilities’ customer base then can be met without an increase in price. The upshot, however, is that third parties such as USG find fewer bargains in the spot market. As USG sees matters, however, the higher spot-market prices stem not from risk pooling but from ProLiance either holding reserve capacity off the market (a reduction in output that drives up prices) or bundling the release of reserve transport capacity with gas (which USG describes as a monopolistic tie-in sale).
Because all we have to go on is USG’s complaint, it is too soon to determine whose understanding of these events is superior. The district judge concluded that it would
never
be necessary to examine these issues and dismissed the complaint, citing Fed.R.Civ.P. 12(b)(6), on three grounds: first, USG has not suffered antitrust injury because it does not buy from ProLiance; second, the suit is barred by the four-year period of limitations in 15 U.S.C. § 15b; third, USG could not prove its claims in light of adverse findings by the Indiana Utility Regulatory Commission in a proceeding to which USG was a party. None of these is a good ground on which to dismiss USG’s complaint — and the latter two are not permissible even in principle, because the statute of limitations and issue preclusion are affirmative defenses. See Fed.R.Civ.P. 8(c). Complaints need not anticipate or attempt to defuse potential defenses. See
Gomez v. Toledo,
A private plaintiff must show antitrust injury — which is to say, injury by
*575
reason of those things that make the practice unlawful, such as reduced output and higher prices. The antitrust-injury doctrine was created to filter out complaints by competitors and others who may be hurt by productive efficiencies, higher output, and lower prices, all of which the antitrust laws are designed to encourage. See, e.g.,
Atlantic Richfield Co. v. USA Petroleum Co.,
Portions of the district court’s opinion equate the antitrust-injury doctrine of
Brunswick
and its successors with the direct-purchaser doctrine- of
Illinois Brick Co. v. Illinois,
A cartel cuts output, which elevates price throughout the market; customers of fringe firms (sellers that have not joined the cartel) pay this higher price, and thus suffer antitrust injury, just like customers of the cartel’s members. We noted and reserved in
Loeb Industries, Inc. v. Sumitomo Corp.,
Now we turn to the statute of limitations. ProLiance was formed in March 1996, and USG did not file this suit until October 2000. The statute of limitations is four years — but, as the district judge recognized, this time runs from the most recent injury caused by the defendants’ activities rather than from the cartel’s inception. See, e.g.,
Zenith Radio Corp. v. Hazeltine Research, Inc.,
To the extent that defendants believe that even new anticompetitive acts and fresh injury within the four years before suit are insufficient, if the joint activity began earlier, that position cannot be reconciled with
du Pont,
which held that old activity (in
du Pont,
a stock acquisition preceding the suit by 30 years) is not immunized, if the potential for a reduction in output is created or realized more recently as market conditions change. Cooperative ventures may begin innocently but acquire market power (or begin to exercise it) afterward; if this occurs, a suit within four years of any anticompetitive activity is timely. This is clear enough if we apply the label “cartel” to what Indiana Gas and Citizens Gas call a “joint venture.” Choice of terminology does not shorten the time for suit. A merger may be complete at closing, see
Concord Boat Coyp. v. Brunswick Corp.,
As for issue preclusion (collateral estoppel): USG’s principal argument is that the state commission did not have “jurisdiction” to resolve a federal antitrust claim, so as a matter of federal law its findings must be disregarded. That’s wrong, for two reasons. First, the preclusive effect of a state judicial decision depends on state rather than federal law. See 28 U.S.C. § 1738. (A state agency acting in a judicial capacity is a court for
*577
this purpose. See
University of Tennessee v. Elliott,
When Indiana Gas and Citizens Gas formed ProLiance, USG and several other customers asked the Indiana Utility Regulatory Commission to block the plan. They offered two lines of argument: first, that ProLiance would itself be a utility that could not come into existence without the Commission’s permission; second, that Indiana Gas and Citizens Gas (which are utilities subject to the Commission’s jurisdiction) did not satisfy the “public interest” standard when forming ProLiance. The Commission rejected the first on grounds that do not matter to this antitrust litigation. It rejected the second after finding that ProLiance serves the public interest by enabling Indiana Gas and Citizens Gas to make better use of their joint reserve capacity.
Petition by Ratepayers of Indiana Gas Co.,
No. 40437,
One month after the state Supreme Court’s decision, USG filed this antitrust action, only to be met by the argument that the Commission’s decision knocks out essential elements of the federal claim. The district court wrote that USG loses because “the issue sought to be precluded — the improper creation and operation of ProLiance — is the same as that involved in [the] prior action that was before the” Commission. But “the improper creation and operation of ProLiance” is not an “issue”; that is far too lofty a level of generality. Putting the matter this way suggests that the district court has equated issue preclusion with claim preclusion. Indiana did not require USG to present its federal antitrust claims to the Commission, so the rules of merger and bar do not block this litigation. Unless the agency decided some concrete issue that also bears on the antitrust claim, USG does not encounter a problem with preclusion.
A finding that “X is in the public interest” is compatible with subsequent antitrust litigation. See
California v. FPC,
Defendants do not rely on the district court’s understanding. Instead they contend that the agency made a favorable, concrete finding: that ProLiance lacks market power. If that is so, then USG’s antitrust claim fails at the threshold. See, e.g.,
Jefferson Parish Hospital District No. 2 v. Hyde,
“To date” is a vital qualifier. The Commission issued its opinion in September 1997. More than six years have passed since then. What is ProLiance doing today? It does not take a leap of fancy to envisage a joint venture behaving itself long enough to win regulatory approbation, and only then applying the squeeze in the market. The agency found that in 1997 ProLiance was beneficial to consumers and that a thriving robust ... secondary market” (opinion at 40) protected third parties such as USG. It wrote: “[m]ost important to our decision is witness Fein-gold’s uneontradicted evidence that, post-ProLiance, the market place continues to function with no ill effects.”
Id.
at 41. “[T]he affected markets are as robust after the formation of ProLiance as they were prior to its formation.”
Id.
at 55. That was 1997. What of 2003? The agency recognized that its record had been compiled quickly and reflected only the initial months of ProLiance’s operations. “There simply is little experience with the actual operation of the alliance.... [Experience under the current agreements may indicate that their actual operation does not comport with the public interest even though we find that they do so now.”
Id.
at 57. Reviewing this decision, the Supreme Court of Indiana made a similar point, observing that, if circumstances change, the agency may revisit the subject.
VACATED AND REMANDED.
