"But states — large, hierarchical, at least somewhat centralised communities — needed agriculture to come into being. Crucial to this story is bread, or, more precisely, grain. It’s no surprise that the oldest states in the world (in Mesopotamia, Egypt, China, and the Indus Valley) were “grain states,” springing up around wheat, barley, millet, and rice. Scott contends that these grains gave rise to states because they were taxable.
Cereal grains grew above ground, ripened about the same time, and could be transported in bulk. You could not have a “cassava state” in West Africa or “potato state” in the New World because farmers might easily bury those tubers, hiding them from the tax collector. Similarly, legumes such as chickpeas or lentils could be slyly picked over a period of time as they ripened. Cereal grains, on the other hand, were “visible, divisible, assessable, storable, transportable, and ‘rationable’”.