There has been a decline in violence, not an increase, and it has been fastest in the countries with the least bridled versions of capitalism – not that there is such a thing as unbridled capitalism anywhere in the world.

The last few decades have been the most peaceful era in human history. Whereas in early agricultural societies human violence caused up to 15 percent of all human deaths, and in the twentieth century it caused 5 percent, today it is responsible for only 1 percent.

Puerto Rico was still poorer than any state in the union and poorer than Mexico—hence the stream of migrants to the mainland—but it was doing better than nearly all its Caribbean neighbors. In 1954, Life, which had labeled the island an “unsolvable problem” just eleven years earlier, described it as “one of the few spots on the globe that all Ameri

Here is Eisner’s one-sentence summary of how to halve the homicide rate within three decades: “An effective rule of law, based on legitimate law enforcement, victim protection, swift and fair adjudication, moderate punishment, and humane prisons is critical to sustainable reductions in lethal violence.”