It's not exactly hard to find anecdotal evidence. For example, Haitian households living in the US had a 2015 median income of $47,200. I don't know exactly h

It's not exactly hard to find anecdotal evidence. For example, Haitian households living in the US had a 2015 median income of $47,200. I don't know exactly how to translate this into per capita terms, but Haiti has a per capita GDP of something like $730. I'm sure that these groups of people are not perfectly comparable in every way, but it's certainly suggestive that people can make a better life for themselves here than in Haiti. How do you think you would fare in Haiti? If you want a more rigorous extrapolation, which tries to account for confounding factors and isn't limited to one pair of countries... you are going to have to look at the research (of economists).