I have heard this line a lot, and it shouldn’t go unchallenged. Most homeless people don’t plan to be homeless anywhere, and certainly don’t plan to move from Detroit to LA to be homeless. Many poor but non-homeless people have never left their state, so it’s pretty hard for me to imagine a homeless person gathering enough money for a cross-country trip to supposedly homeless Mecca. And most homeless people are only temporarily homeless.

Many people also aren’t aware of the fact that a sizable percentage of homeless people have jobs. So “poor life choices” can prevent a person from having a roof over their head, but apparently not from working.

No, what is clear is that there is a direct relationship between an influx of people, lack of new housing, and an increase in homeless people. Did people suddenly become more predisposed to mental illness and drug addition when housing demand went up? Of course not. Most of the homeless people in a city are from that city.

In places with Housing First, there is a huge decrease in homelessness of course, but also in other associated problems like mental illness and drug addiction.

> it shouldn’t go unchallenged.

Well, you should talk to the homeless people then. I live in SF and am on first-name terms with close to 20 homeless people. All but one of them came from outside SF.

You'll often hear of "point in time" surveys which claim that 70% of homeless people lived in SF when the became homeless. But this is a self-reported survey, without any proof, and the definition of "lived" is very loose: even if you were living in a homeless shelter and got evicted, you'd be classified as having "lived in SF when you became homeless".

I read an interview of a homeless woman from Minnesota, who explicitly said: I had a choice: would I rather be homeless in Minnesota, or homeless in San Francisco; so I hopped on a bus and came to SF.

SF has a very permissive culture, and an open drug scene, so it is attractive to anybody who's homeless.