An answer to you and to most of the other comments in this thread: This isn't what I was getting at. Take for example university students. Their earning power

An answer to you and to most of the other comments in this thread: This isn't what I was getting at. Take for example university students. Their earning power is significantly smaller than more experienced people. They also tend to need a lot less money, because they're usually single, don't often have a mortgage, live in a small apartment or in their parent's house, etc. Many students work part-time in a restaurant or similar. For them, this will probably be a "livable wage", whether because their needs are smaller as discussed, or because they're relying to some extent on their parents. Take another person of the same age, but who has a family and no parents for support, and assume they earn the same. For them, this same wage is not livable. How would you statistically separate these cases? I'm not saying there isn't a way, I'm just wondering what it is!