Journalist Thomas Fuller returned to the United States after 27 years abroad, mainly in Asia. He moved to San Francisco and wrote about the reverse culture shock he experienced. The thing that struck him the most was the disparity between the wealthy (ganja yoga, organic ice cream sandwiches, vegan shoes, Bluetooth compatible toothbrushes) and the poor (outbursts of the mentally ill on the sidewalks, vaguely human forms inside cardboard boxes).
From NYT:
Greater Bangkok, a sprawling metropolis with more than 10 million people, has 1,300 homeless people, a survey this year found.
San Francisco has less than one-tenth Bangkok's population but six times as many homeless people. I'm sure you could fill a book with the reasons for this. Ms. Nopphan believes that homelessness is more intractable in rich societies. "In wealthy countries there are systems for everything," she said. "You're either in the system or out of the system." There is no in-between in America. In Bangkok, by contrast, rich and poor coexist. There are vast tracts of cheap, makeshift homes and a countryside where people in the cities can return to if they lose their jobs or hit hard times.