What are some examples of the “Fourth World”

Question

Specifically using Wikipedia’s definition of “Sub-populations existing in a First World country, but with the living standards of those of a Third World, or developing country."

Answer 1

I think some of the easiest example is to look into minority communities in the US for example. Even though the us is post-industrial and economy wise one of the richest. You have communities across the country where deaths do to childbirth mirror does of developing nations. As well as lack of food, healthcare, water.