[AnimalMuppet]

What I think you're saying is, prices drop in Portland, so people move there from city X, which drops demand in X, so prices drop in X.

One problem, though, is "stickiness". I wouldn't move to a different city for $1/month. I probably wouldn't move even for $100/month. Why not? Well, I'm not single, and I have kids. It's not just that I'd upset everyone's routine - I'd also have to move all this stuff. I'd also have to sell my place and buy (or rent) a new one. Total cost to me: Probably in the $20,000 range. I'm going to do that for $100/month? No way. Even for $1000/month, it would take 20 months to pay back, not counting the time and aggravation.

So cities are "sticky". I'm stuck here; it takes a seriously better situation to break me loose.

Many people have lower thresholds than I do; but for most people, the threshold is some way above zero. (Exceptions do exist; if the current situation is socially or emotionally difficult, they may move to something even if it's economically worse.)