This may set another cat amongst the pigeons here but a Puerto Rican friend who visited the DR said, as we were driving through the Cibao and up to the Saman? peninsula - "this is what Puerto Rico must have been like 40 or 50 years ago".
40, 50 or 60 years ago the DR and PR looked more the same. Even the DR was not as it is now, it was much poorer, less populated and the population was more rural. Even entire towns looked different; for example, Hig?ey was tiny compared to now, composed mostly of wooden homes with thatch roofs and dirt floors, and most of the population was white, according to an account by a Spanish immigrant that arrived in the early 1940s.
It was pretty much the same in PR, but since then they did what the DR is, in part, doing now.
Fast economic growth (like the DR), massive foreign investment (like the DR), control of immigration (unlike the DR), massive emigration (more or less like the DR), unorthodox birth control practices (not like the DR).
50 years later, PR is considerably wealthier and more developed than it was and compared to most Latin American countries.
As for the unorthodox birth control practices, with that I'm referring to the forced sterilization of many women (mostly poor, mulatto and black) without their consent or knowledge among other things. This is also part of the reason (the other is that most of the people that were forced to emigrate tended to be darker) why the Puerto Rican population went through a whitening process during much of the 20th century.
Certainly, practices such as those, as effective as they are at controlling fast population growth and ensuring per capita wealth to increase rapidly, vastly improving living conditions in a very short period of time; are simply not an option in this day and age of supranational organizations, NGO's, Human Right commissions, etc.