crack dealing, robbery and rape. Violent crime was a gruesome, constant companion. And things were about to get even worse. Much worse. All the experts were saying so. The cause was the so-called superpredator. For a time, he was everywhere. Glowering from the cover of newsweeklies. Swaggering his way through foot-thick government reports. He was a scrawny, big-city teenager with a cheap gun in his hand and nothing in his heart but ruthlessness. There were thousands out there just like him,   we were told, a generation of killers about to hurl the country into deepest chaos. In 1995 the criminologist James Alan Fox wrote a report for the U.S. attorney general that grimly detailed the coming spike in mur- ders by teenagers. Fox proposed optimistic and pessimistic scenarios. In the optimistic scenario, he believed, the rate of teen homicides would rise another 15 percent over the next decade; in the pessimistic scenario, it would more than double. "The next crime wave will get so bad," he said, "that it will make 1995 look like the good old days." Other criminologists, political scientists, and similarly learned forecasters laid out the same horrible future, as did President Clinton. "We know weve got about six years to turn this juvenile crime thing around," Clinton said, "or our country is going to be living with chaos. And my successors will not be giving speeches about the won- derful opportunities of the global economy; theyll be trying to keep body and soul together for people on the streets of these cities." The smart money was plainly on the criminals. And then, instead of going up and up and up, crime began to fall. And fall and fall and fall some more. The crime drop was startling in several respects. It was ubiquitous, with every category of crime falling in every part of the country. It was persistent, with incremental de- creases year after year. And it was entirely unanticipated-especially by the very experts who had been predicting the opposite. The magnitude of the reversal was astounding. The teenage mur-