Safety considerations should also be a factor when considering whether or not to share an apartment or house. The old saying that there is safety in numbers has a lot of truth in it. A roommate's assistance can be invaluable during an emergency or illness, not to mention the added feeling of security a roommate provides. Appeasing your parents can also be a deciding factor in choosing to room with someone. Parents often worry about their children starting off on their own in the big city, and a roommate can go a long way towards assuring them that you are not all alone.
Convenience is an obvious, but often overlooked, asset to communal living.
Somehow, housework and the other drudgeries of life are not quite so bad when the responsibility is shared. Roommates are also great for answering the phone when you're not at home, loaning you money for the bus when you can't find your wallet, and letting you into the apartment when you left your keys at a friend's house in San Diego.