is an anomaly with no true counterpart anywhere in the world. The island's economy is hostage to this circumstance. It is a victim, too, of nature. Puerto Rico has virtually no natural resources. It is self-sufficient only in people, of whom it has long been a net exporter. For other resources it must rely on the outside world, primarily the United States, its chief trading partner for nearly 100 years.
Like Taiwan and South Korea, Puerto Rico faced a postwar challenge. It had to devise an economic...