Punitive damages have deep roots in American and English common law, but their nature has changed here over time. “Until well into the 19th century,” Justice John Paul Stevens of the Supreme Court wrote in 2001, “punitive damages frequently operated to compensate for intangible injuries” like pain and suffering or emotional distress.

These days, driven by the structure of the American civil justice system, entrepreneurial plaintiffs’ lawyers and the populism they embrace, punitive damages are used to send messages to large corporations, to fill gaps in regulation and to reward successful plaintiffs with multiples of what they have lost. Distinctive features of the American legal system  civil juries, class actions, contingency fees and the requirement that each side bear its own lawyers’ fees  all play a role in amplifying punitive damages.

Punitive damages are so embedded in the American legal system that the rationale for them is rarely explored. One of the best explanations came from a German Supreme Court decision in 1992, which said the concept had four main purposes: to punish the offender for “uncivilized conduct,” to deter the offender and others from doing similar things, to reward the plaintiff for enforcing the law and so improve “general law and order,” and to supplement inadequate compensatory damages.

The case decided by the German court, like the one involving Kurt Parrott, was an effort to enforce a judgment from an American court against a defendant who had no assets in this country and refused to pay. Ordinarily, it is a relatively routine matter to ask a foreign court to enforce an American court judgment. Not so when punitive damages are involved, even where the conduct in question is shocking.

The German case, for instance, involved sexual abuse. In 1985, a state court in Stockton, Calif., entered a $750,000 judgment, including $400,000 in punitive damages, against Eckhard Schmitz for abusing a 13-year-old boy. Mr. Schmitz would not pay, and he fled to Germany while he was appealing a 13-year criminal sentence for engaging in sex with other teenage boys.

But the German court nonetheless said that the dangers of allowing punitive awards outweighed the benefits. The plaintiff should not get a windfall, the court said, and should not be allowed to act as a “ ‘private public prosecutor’ infringing the German state’s monopoly on punishment with its associated safeguards.”

The German court did enforce the $350,000 compensatory award. The Italian court, by contrast, refused to enforce any of the $1 million award to Kurt Parrott’s mother because the Alabama judge had not said how much of it was for compensation and how much for punishment.