Take an extreme case, if one person in a country own all the robot and these robot in turn make other robot to do all the work, then to whom could he sell his products? All the other people are jobless and without income, they live at social welfare level. His production will continuously shrink until it mets the demand from all the other people's consumption at lowest social welfare level, and those social welfare handouts are coming from his own production too (in tax form)
If this comes to pass you ARE the government. This is an instant autocracy, and maybe even a theocracy if you are into people worshiping you. Set the rules for the sustainment of the people that you like.
Take a slightly less extreme case and you end up in an oligarchy.
Take a messy, fractious bunch of folks arguing amongst themselves (like we actually have today) and play it forward to this level of technology, and we will have a messy fractious set of possible solutions being played out including some interesting communist and socialist experiments as well as markets with regulated competition, and likely at least a few oddballs or free-zones, especially if we go interplanetary.
There are many solutions to this problem, and I'm sure some of them are beyond imagination today.
Just because you have a machine that can make any material object does not mean an end to labor, it will not invent NEW things, create the BEST music, the most AUTHENTIC hobby/folk crafts, the most time consuming work of art, the joy of time with family, experiences in nature, trendsetting, communication, politics, travel and cultural exchange, historical, theoretical, or practical science, or any number of undertakings that define the human condition. As we have seen, a rising standard of living increases the desire for luxuries, inventing new ones will be a lucrative job in itself. Just because nobody is having to slave away in a sweatshop (at least in the neighborhood of earth...) does not mean the end of labor, simply the end of manufacturing as we know it.
