Why are people from islands such as Jamaica and Mauritius backwards and underdeveloped? Compared to mainland countries/cities like the USA/New York?

Why are people from islands such as Jamaica and Mauritius backwards and underdeveloped? Compared to mainland countries/cities like the USA/New York?

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Why are people from islands such as Jamaica and Mauritius backwards and underdeveloped? Compared to mainland countries/cities like the USA (NYC)/Germany?
Why are people from islands such as Jamaica and Mauritius backwards and underdeveloped? Compared to mainland countries/cities like the USA/New York?
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