Walter Scheidel in Aeon:
Blame inequality on climate change. Until the end of the last Ice Age, some 12,000 years ago, our ancestors lived in small foraging groups. They moved around a lot, owned very little, and passed on even less to the next generation, sharing any windfalls on the spot. The Holocene changed all that. Rising temperatures allowed humans to settle down to farm the land and domesticate livestock; collective management of resources gave way to private property rights, and new norms made assets hereditary. Over time, the cumulative rewards of brain, brawn and luck came to separate the haves from the have-nots.
This process of stratification was reinforced by the creation of states, as political power and military muscle aided the acquisition and preservation of fortunes and privilege: more than 3,000 years ago, the ancient Babylonians were well aware that ‘the king is the one at whose side wealth walks’. With the emergence of mighty empires, and as slow but steady increases in the stock of knowledge expanded economic output, the concentration of income and wealth reached previously unimaginable heights.
The principal sources of inequality have changed over time. Whereas feudal lords exploited downtrodden peasants by force and fiat, the entrepreneurs of early modern Europe relied on capital investment and market exchange to reap profits from commerce and finance. Yet overall outcomes remained the same: from Pharaonic Egypt to the Industrial Revolution, both state power and economic development generally served to widen the gap between rich and poor: both archaic forms of predation and coercion and modern market economies yielded unequal gains.
Does this mean that history has always moved in the same direction, that inequality has been going up continuously since the dawn of civilisation? A cursory look around us makes it clear that this cannot possibly be true, otherwise there would be no broad middle class or thriving consumer culture, and everything worth having might now be owned by a handful of trillionaires.