Maybe she made a calculation (or just hoped) she could move up and pay off her cc. debt. And it went disastrously wrong. Maybe people aren’t taught about debt. In the US, if I recall correctly, you can get into never ending credit card debt just by paying the minimum amount, because it is legal for banks and CC companies to let you pay less than the interest rate and fees. This is what I mean: http://www.cracked.com/funny-4179-credit-cards/
But what you say means that SF and imilar cities face a segregation between haves and have nots that looks like a bigger problem. The rich live there, the poor live away and commute for hours to serve. That’s terrible. That’s what I read in Talia’s post.