In this paradigm, government--all government, from central to local--would be on a strict budget. The amount of money it would receive would be based on how many people were living in the nation, and nothing else. (Whether/under what circumstances a nation would still allow taxes or public debt in addition to that budgeted money is a decision a nation would have to make.) As I said, the money collected is not a tax because individuals could avoid having money collected by spending it on any legal thing, including investing it--or giving it to churches or politicians or charities, etc..