So put it into real numbers.
Elsewhere I've stated that it is possible for a family of 4 to eke it out (no room for emergencies) on a single, full-time job paying $9 an hour with a take-home pay of $17,000 annually. Other people claim that childcare expenses alone require as much as $18,000 a year per child. Furthermore, does an employer have to ask how many children a man has and alter the wage based upon that information? Is it okay to pay single people one wage and a father of 8 another? Are all employers required to pay wages sufficient to support a family of 10 for every job position?
In the US, I'm pretty sure it's illegal to ask a potential employee about their children or familial status.
The big problem is that no two people can agree upon what constitutes a minimum standard of living. In my opinion, this is about $30 a week of food per person plus a roof and basic medical (occasional checkups and the occasional antibiotic subscription plus conventional first aid). Other people consider that baseline impossibly cheap.
Exactly this. What are the details and exact numbers of what constitutes a "just wage"? If we were to go by what LeoXIII says, in my opinion, the current state of wages in the US is perfectly fine to live a frugal lifestyle. It is already "just" when you consider that government assistance takes care of many costs (eg., medical) for low earners.
This meal cost the poster $0.78, and he could have gotten the ingredients for cheaper too:
https://www.reddit.com/r/food/comments/4yxt9d/just_moved_out_of_home_and_followed_reddits_rice/This is what I consider a frugal and healthy meal, which is more than affordable. However, others disagree.
Let's be honest, many people consider a "just wage" one where they can live a middle-class lifestyle. That as long as you are employed "somewhere" (doesn't matter what your job is -- could be pulling weeds or bagging groceries), you should be paid enough to life a middle-class lifestyle. Nothing wrong with that. But I think at that point you are talking about something other than "justice".
In any case, the questions posed by Akavit (and Miriam) need to be answered.