I don't think that is true. It is next to impossible to live poorly like one could in the Third World in the US. Besides it being illegal to bring children up in such an environment. Law and expectations dictate that it is much harder to be poor here than abroad.
IF your conclusing is correct then why is it that so many poor people particularly in Mexico are trying to get into this country illegally through the boarder? We have the best standard of living and the most open boarders in the world and people are clamoring to get in including the poor. Poor people for several centuries now have been saving and saving and even slaving- ie. becoming indentured servants as some of my ancestors did to come to the U.S. Do people go hungry in this country yes but it is NOT like the starvation in Africa or even Latin America.