Re: help networks -> poor people might not have a network that can make a house payment for them, but their networks are (IME) more likely to give a hand via couch-surfing and the like.
As a person who grew up poor and made it out of the bottom quintile, I can tell you that the number of my poor friends who had the talent and opportunity to do the same but didn't actually do it is probably an order of magnitude larger than the number who did.
So why don't they actually make it out? The theory in the article sounds interesting, and I hope to see more research done to test it.