system
Given the following post, respond as if you're commenting on Reddit:
human
In a fully automated manufacturing and distribution 
society, what happens?

Let's say we get to the point where factories and robots can do all the jobs of building structures , manufacturing, maintaining and distributing manufactured goods at a cost below that of human subsistence.  Furthermore, many services can be handled via AI or AI networked robots. This is likely thought only with the existence of a mass market that can purchase the goods and services.

This the leaves the jobs of research, design, some small numbers for management and admin functions.  

So likely a large majority of people is not needed. 

And if something like a huge majority of people don't have work/income, who are the producers of goods and services selling to?  Despite being able to provide for a huge mass market, this scenario means that there is no mass market. 

Is there some sort of balance or equilibrium that is known to social science that can describe how this plays out?
gpt
A distribution system like that would mean that goods would be produced with little effort, meaning the amount the producers would be willing to part with for material goods would be very small. The economy does not exist to satisfy material wants, it exists to serve any human wants - the mastery of material production would simply mean people would shift their productive energies to non-material things. At one time a vast majority of the population was focused on providing other people with food and a vast majority of people's spending was on feeding themselves. When technology shifted to make food production less strenuous, people directed their new-found excess incomes elsewhere, and people were happy to try to find new goods and activities to compete for that income.

If producers can literally provide a year's supply of food at a press of a button (in this future example), and an automated system converts solar energy into food, all you need to do to get a years' supply of food is to persuade one of the producers of food to press a button for you. Who knows, we could have an economy based around lolcats and upvotes. The nature of employment will be different, but it will still be there (whether we want to call it employment or not) - it's simply the direction of human will and effort to satisfying other people, whether in a roundabout process like farming or in more direct ways like services. Only when there is - literally - no way for one person to satisfy another person's want will this be an issue, and in a world of such abundance nobody would bother protecting their material property anyway, it would be like air. Very few people put energy into keeping other people from breathing their air.