Jamaica’s not doing all that badly on the GDP scale compared to the other larger countries in its region. Comparable to the Dominican Republic, better than the Central American countries other than Panama and Costa Rica, way better than Haiti.

#1 – a certain few British-Caribbean countries are at the top, most notably Barbados and the Bahamas, two countries that have been stable liberal democracies since independence and arguably the most culturally “British” of the islands (both actually have sizable white and mixed Afro-European populations, for example the green-eyed Rihanna from Barbados). Also Trinidad is high up there with its mixed African and Indian population, it has a developed industrial and petroleum-based economy. By contrast, Guyana is one of the poorest countries in the hemisphere while Jamaica, the largest of the British-Caribbean countries, is a notorious train-wreck economically, though it has managed to maintain a turbulent democracy since independence.

They’re all small countries, possibly that’s the main factor.

Puerto Rico’s young and ambitious have been moving to the (rest of the) U.S. for decades

While the bulk of the Puerto Rican migration to the Northeast has run its course, when it was going strong I can assure you it was not comprised of the island’s ambitious people.

Argentina’s decline has been a relative one rather than a real one, Argentina is still much more proseperous today than it was 100 years ago, it’s just that some other countries have grown even faster and a few have surpassed it, Chile being the most notable example. One legacy of its past relative prosperity is that its income distribution is somewhat more equal than Brazil or Mexico, which is why Argentina “feels” so much more middle class and prosperous than those two countries (although Brazil is making great strides recently to reduce inequality). It may be noted also that Argentina actually has a higher birth rate than Mexico or Brazil, so GDP per capita may skew lower to account for more children – household income may be a better measure.

Puerto Rico’s young and ambitious have been moving to the (rest of the) U.S. for decades, first to NYC and the northeast, more recently to Orlando and south Florida, to the extent that there are now more Puerto Ricans living in the U.S. off the island than on the island. PR and Michigan were the only two states/jurisdictions to suffer a population loss between 2000 and 2010. Maybe those left behind are older and generally less vigorous and that explains the lower fertility rate?

http://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&ctype=c&strail=false&bcs=d&nselm=s&met_y=ny_gdp_pcap_cd&scale_y=log&ind_y=false&idim=country:TTO:BHS:BRB&ifdim=country:region:LCR&tunit=Y&pit=1011744000000&hl=en&dl=en&icfg=d5bncppjof8f9_%253A59%253Acountry%26%26BRA:-14:-41:

Obviously, Haiti is on the other end of the see-saw.