This аppeal brings before us a recurring problem in the administration of the diversity jurisdiction of the federal courts. A plaintiff brings a suit in a state court. The defendant removes it to federal court. To keep the case
from
being remanded to the state court, the defendant must show not only that the parties are of diverse citizenship, ordinarily a straightforward thing to show, but also that the amount in controversy exceeds the jurisdictional minimum, which is now $75,000 thоugh it was only $50,000 when the suit was brought. 28 U.S.C. § 1332. Since the plaintiff will not have had to allege an amount in controversy when he filed his suit in state court (or, if there is a minimum amount in controversy for suing in that court, invariably it will be substantially lower than the federal minimum), and since his stakes in the litigation are likely to be better known to him than tо the defendant, there is a risk that the plaintiff will not contest jurisdiction upon removal, but later, should the case turn against him on the merits, will claim that the federal minimum amount in controversy has not in fact been met. In
Shaw v. Dow Brands, Inc.,
The present case began as a class action filed in a state court in Alabama. A class of Alabama consumers sought damages under the state’s antitrust law against manufacturеrs of brand-name prescription drugs, charging that they had violated that law by colluding to raise the prices of their drugs. The class members, though they had nоt purchased the drugs directly from the defendants, but rather from retailers, claimed that the retail prices which they had paid were inflated by the рrice-fixing conspiracy, because the manufacturers’ increased prices had been passed in whole or part down the chain of distribution to the ultimate consumers. If brought under federal antitrust law, such a claim would be barred by
Illinois Brick Co. v. Illinois,
Although the complaint that the plaintiffs filed in state court did not specify the amount of damages sought, or otherwise suggest an amount in controversy, the defendants removed the ease to a federal district court in Alabama, which in turn transferred it to a federal district court in Illinois. Seven months later, the plaintiffs moved to remand the case to the Alabama state court on the ground that the amount in controversy was in fact lеss than $50,000. The district court refused to do so, and proceeded to enter judgment on the merits for the defendants on the ground that Alabama antitrust law dоes not regulate interstate commerce. (The drugs bought by the plaintiffs had been shipped across state lines.) The reach of that law had bеen unsettled when we decided
Huggins,
’but the defendants persuaded the district judge that it had since been determined in their favor by
Abbott Laboratories v. Durrett,
The defendants argue that the plaintiffs’ seven-month delay in challenging federal jurisdiction operates not as a waiver or forfeiture of their right to make such a challenge — such an argument would be frivolous, see, e.g.,
Walters v. Edgar,
Had the plaintiffs, before the removal of the case to federal court, stipu *671 lated that they were seeking less than $50,000, the court would have been required to remand the case to state court without further inquiry. It would have been plain that the case was not within federal jurisdiction. But the converse-that jurisdiction can be assumed without further inquiry if the plaintiffs stipulate that they are seeking more, or don't stipulate at all-does not follow. Jurisdiction cannot be conferred by stipulation or silence. For that matter, it cannot (with immaterial exceptions) be destroyed by stipulation after jurisdiction attaches. If the plaintiffs' original claim was worth more than $50,000, removal was propеr, the case was within federal jurisdiction, and the plaintiffs could not defeat that jurisdiction by scaling back their . claim.
Shaw, though it contains language thаt sorts ill with the principles that we have been expounding (language we now disapprove), is distinguishable. It was a personal injury suit in which the plaintiff was suing for permanent damage to his lungs. It is difficult to see how, if he succeeded in proving his claim (and there was no suggestion that it was spurious), he would be entitlеd to less than $50,000 (the then jurisdictional minimum in federal diversity cases, as when the present case was filed). So improbable was that hypothesis that we wеre not required, merely on the basis of the plaintiffs belated and unsubstantiated assertion, to remand for a factual inquiry. This case is quite different. We must bеar in mind that in a class action at least one plaintiff must satisfy the minimum amount in controversy all by himself; that the plaintiffs are purchasers of drugs for their оwn use; and that the damage period is only two years. One of the named plaintiffs may have incurred $50,000 in damages from being overcharged for drugs over a two-year period, if only because the Alabama antitrust statute affixes a $500 penalty to every violation, as we explained in Huggins. So еven if the overcharge was trivial, someone who over a two-year period made 100 separate purchases of drugs the pricе of which had been inflated by the defendants' price fixing would satisfy the jurisdictional minimum. That is possible but of course not certain-indeed sufficiently uncertain, just as in Huggins, to require an evidentiary hearing before the motion to remand could be denied. The judgment of the district court is therefore vacated and the case remanded to that court for the hearing.
VACATED AND REMANDED.
