Well, one data point: "38% of homeless survey respondents reported that they first became homeless outside of San Francisco or were relative newcomers, having l

Well, one data point: "38% of homeless survey respondents reported that they first became homeless outside of San Francisco or were relative newcomers, having lived in the City for three months or less." And that's actually a significant decrease from the 2007 survey. http://www.sfgov.org/site/uploadedfiles/lhcb/homeless_count/SF2009HomelessCountFINALReport.pdf http://www.sfgov.org/site/uploadedfiles/lhcb/homeless_count/...