A commonly held theory of the emergence of states is that agricultural surplus encouraged the development of complex political structures. Previously I outlined a theory that agricultural production which requires organization is the trigger for state formation. Most of the time this happens with agriculture in marginal environments (deserts or desert-adjacent areas) which require irrigation and coordination with annual weather events, and explains why states don't emerge in rich environments (like volcanic temperate rainforests>) which would otherwise be more intuitive. In China, this occurred because the crop that was adopted and fit the local environment was labor-intensive. That is: in all these examples, food production and organization emerged together and created a positive feedback loop.
A new theory holds that agricultural production makes food (and neolithic wealth) transparent, and enables the kleptocratic aspect of states.