The Patent Act empowers a court to issue an injunction “to prevent the violation of any right secured by patent.” Whether a court will permanently enjoin an infringer depends on whether (1) the patent holder would suffer irreparable harm otherwise, (2) its legal remedies are inadequate, (3) the balance of hardships favors the patent holder, and (4) the injunction would not disserve the public interest. Similar factors inform the grant of a preliminary injunction. The Federal Circuit often says that the harm from patent infringement is irreparable if it cannot be measured. I say that such harm is irreparable because it irreversibly destroys wealth.

Patent infringement irreversibly obliterates wealth when it impedes society’s technical progress. Patent infringement does more than transfer wealth involuntarily from the patent holder to the infringer; it also harms third parties by devastating the surplus that consumers would derive from using the product practicing the new technology. Damages are impotent to cure that harm to the public interest. A court’s order of damages can no more recreate the wealth that has been or will be destroyed by an act of patent infringement than it can restore an ancient redwood after the axeman has felled it.