Yes, and weather makes a big difference: anyone who has any experience going about Manhattan knows that many chronic homeless will go to a shelter by choice when it's bitter cold, but when it's warm enough to stay at their preferred street spot, they would rather stay there and have to be forced to move by police (or property owners as the case may be.) This is true through many mayoral adminstrations and decades of waning and waxing of numbers of homeless on the streets. (Also should be noted: it is very rare to see any kind of homeless families on the street at night in NYC - it is virtually ALL single individuals. Families don't risk being on the streets at night.)

So I am VERY open to the argument that many of the homeless on the streets of California cities are recent transients from other states - they go there for the weather! So they can stay outdoors instead of going to a shelter! (Heck I would make the same choice!) And they have many more subsidies than elsewhere, so moving there if a homeless person can manage it, via Greyhound or whatever, is a smart choice for them.