The artificial evolutionary mechanism which causes Silicon Valley to have a strong economy (because of the high density of wealth and talent) while simultaneously creating a permanent homeless problem.
Alicia: Hey, I'm thinking of relocating to the Bay Area. I'll be making $170K and my husband will stay at home to take care of the kids. Do you think that's enough? Diego: Hmm, well, move into a bad neighborhood, with a 2 hour commute and a shitty school district and you're cooking! Alicia: Haha, wait.... You're serious? Diego: Ohh Yea! You'll be cooking a lot too unless you want to spend $15 on a burger. Fast food employees gotta pay rent too! Thanks to this Housing Bubble