Another Dominican here. I have been away from the Dope for a while, and the internet in general. But when I came across this thread I knew that the Illustrious Delirious would be here to impart some wisdom. And lucky me I find a fellow countryman…
I am not smart enough to answer the OP’s question, but I have some ideas:
Spain was a somewhat “benevolent” empire. I have mentioned it before, but Spanish conquistadores had no qualms about shagging women of all colors, and of course fathering their kids (same as the French and English), but unlike the French and English, and much like the Portuguese, they did not consider these kids as slaves, more like “lesser” children. This created a racial “middle class” of sorts, where the mulattos were considered to be above of the black slaves, and lower than the white rulers.
Much shagging and mixing ensued, making sure that the mulattoes ended up being the majority of the population, and creating our own brand of racial relations (which we share with a few Latin American countries). The racial tension between France and Haiti was significantly higher than that of Spain and Hispaniola.
Unlike Haitians and their justified paranoia of all things “white”, the Spanish colony never really saw the white Europeans as the enemy, insofar as the Spanish colony was so poor that at times master and slaves (and mulattoes) shared the same indignities. The slaves were slaves, thus not really in an ideal position, but their conditions were vastly better than their French counterparts (and the Spanish ruling class was vastly poorer than their French counterparts). The movement for ending slavery was not really successful, seeing as blacks/slaves were a minority in the Spanish colony (unlike in the French colony were the slaves accounted for over 80% of the population), and because all things considered being hung for revolting was worse than what they were going through.
When the country gained independence from Haiti (after Haiti, who saw the Spanish as a potential danger to their own independence expelled them out) there was a strong movement to return the colony to Spain as a protectorate, and it indeed happened shortly after defeating Haiti, but the colony eventually revolted (mainly because Spain was pretty ineffectual at improving the conditions in the colony, seeing as they were tied up elsewhere). The D.R. has always been pro-Spanish, even when it strongly supported the independence wars of other Spanish colonies. We had a lot more people with which to trade, and in fact trade improved once the Spaniards were thrown out (the French colony came about after a chain of events that started with Spain insistence that their colonies not trade with any other European empire). Spain had no resources to fight to regain the colony, but they did not close the trade. The newly-independent colony was also open and willing to foreign investors, and has always been a friendly place to invest, and more attractive to investors, we had more natural resources, more educated people, a lower population density with lots of unoccupied and very fertile land.
Another thing that has been mentioned, and which bears repeating, is that bad as some/most of our rulers have been (Trujillo was as bad a dictator as anyone, don’t be fooled by the size of his turf), but they wanted to have something to show for, so even when they bled the country there were things being done, and sometimes it’s easier to get things done when you don’t have to ask people’s opinion. Haiti’s rulers were as bad/almost as bad as ours, but they couldn’t care less if Rome, er Port-au-Prince burned while they fiddled.
And finally, we have to thank another MF of a president for the fact that we have a relatively healthy environment (Haiti is mostly a wasteland in comparison): Balaguer. However much I hate the dude, and however unethical his methods for achieving this were, he stopped deforestation (cutting trees without a permit from Forestry is illegal, even in people’s own backyards).
There is much more to this than that, but it is very hard to explain these things in 500 words or less.