Let us assume a city state, like a US county, with a main city, surrounded by agriculture. Let us assume a temporarily fixed population and no outside trade. Let us assume that the urban population is 90% and the rural population is 10% So the rural population has to grow food at 10x subsistence for just the rural population. Let us assume that each family requires $100 per week above subsistence to survive. Let us assume that the currency (liquidity, not value) circulates thru each family 4x per year. So each family contribution to the annual GDP is 4x52x$100 or $20,800. The total annual GDP is simply the number of families times that amount. So with 10,000 families, we would have a total annual GDP of $208,000,000. So basically each family on average has to generate that much paid labor per year to survive at that standard of living (assumed higher than subsistence). Let us assume that currency wears out each year, so the government has to produce $52,000,000 in currency each year, which circulates 4x, and then tax at a rate of $52,000,000 per year. This completes the liquidity cycle. We are assuming that nothing slows down the flow of money to less than 4x per year, and that the amount of currency produced each year, meets the minimum. This is steady state. How is the prosperity distributed, and how does it respond to disruption? That is the next post.