The US is a big place, which averages away the extremes. In San Francisco, population 868k, there are about 10-12k homeless folks (http://www.sfgate.com/bayarea/article/San-Francisco-homeless...), which puts it at over 1% homelessness. That's a tragic number for such a wealthy city.
It's only a tragic reflection on the city if you assume all the homeless are born and raised there. How many of those migrated there from colder climates? How many were given a bus ticket by their home city and sent there?
SF spends an absolute fortune on homeless people. That, coupled with its temperate climate, makes it a magnet for many types of homeless people.
Correct, but I have never seen such concentration of homeless people anywhere in Spain, where climate varies significantly as well, and economic conditions are historically harsher. But there's a safety net that prevents most people from falling all the way down.
SF spends an absolute fortune on homeless people. That, coupled with its temperate climate, makes it a magnet for many types of homeless people.