The number one thing you never want to hear from your roommate is, «I quit my job out of the blue today!» It would be a totally different situation if they got laid off or fired, because then at least they might have some severance or be able to collect unemployment. It is also totally above board if you know that their parents are paying their bills or they have a sweet little pocket of money stashed away in one of those nice little savings accounts. But if you know that they are spending every penny that comes into their bank account within the first week they get it, rarely pay bills on time, and aren’t particularly proactive with their career, you certainly have good reason to worry. 

The good thing about roommates is that you do have a transactional relationship, so if they don’t pay the rent, they know that they’re in the wrong…