The first time I travelled from Santa Domingo, which was called Ciudad Trujillo in those days—as the dictator had named it after himself—to Port-au-Prince, I had the sensation that I was moving from one planet to another. It's the same island, but they are so different.
There is not a great deal that can be learned from the relative success of the Dominican Republic and that can be applied to Haiti. Haiti was damned by history from the beginning, and has never really recovered from that. Having defeated the army of Napoleon—and, I think, the brother-in-law of Napoleon, who was a general—the Haitians were then subject to crippling reparations by the French. In addition to that, the American government, which was still a slave government at that time, imposed sanctions and said there could be no trade with Haiti. That prohibition went on until the beginning of the 20th century. So they got off to an absolutely appalling start and never really recovered from it, in the course of which, starting with the French, their forests were cut down, so that every time it rains, what little is left of the soil washes down into the Caribbean.
Unfortunately, it's not a terribly helpful comparison, but they are together, and they can do things together that can be productive. Now, the Dominican Republic is in some ways doing quite well; there is a lot of investment money. Some of that would like to move into Haiti to take advantage, in relative terms, of the cheap labour, and that would be advantageous for Haiti in getting more industry moving. That means there has to be more roads or more connections. The road system in Haiti, as I'm sure you know, is mostly non-existent, and where it does exist, it is absolutely appalling—except for the run from Port-au-Prince through to one part of the Dominican border.
So you need more roads to make these industries work and to have industries in the north that can move goods into the Dominican Republic. You also need to clear out the ports; there is not a single harbour in Haiti that can take vessels with the normal draft of commercial cargo ships.