BALTIMORE – Puerto Rico is once again in crisis, both politically and economically. A United States territory with more than three million people, it has a larger population than many US states. But its population and real (inflation-adjusted) output have been falling since 2006. More than half of native-born Puerto Ricans alive today have left the island, most of them for the US mainland. The territory’s per capita income is around half that of the poorest US state, Mississippi