Even if you assume that their income is entirely fixed, I don't think you believe that all of them live exactly as cheaply as they possibly can. I'd say if you

Even if you assume that their income is entirely fixed, I don't think you believe that all of them live exactly as cheaply as they possibly can. I'd say if you can possibly survive without the heating, then it's better to do that for a while than borrowing money and end up even more dependent on your salary, being a week away from ruin rather than a month. In short, payday lending is a short term solution that make things worse in the long term, even when it is free of interest.