Over at Vox, Peter H. Lindert, Branko Milanovic, and Jeffrey G. Williamson look at the issue.
How does inequality in today’s least developed, agricultural countries compare with that of ancient societies dating back to the Roman Empire? Did some parts of the world always have greater income inequality than others? Was inequality augmented by colonization? Did the industrial revolution lower inequality or raise it?…
Some key aspects of inequality have been uncovered by this initial look at ancient societies.4 On the average, income inequality in today’s countries is not very different than it was in distant times. However, the extraction ratio – how much of potential inequality was converted into actual inequality – was significantly bigger then than now. This ratio measures how powerful and extortionary are the elite, its institutions, and its policies. While a relation between conflict and actual inequality has proven hard to document on modern evidence, the introduction of the extraction ratio might shed brighter light on that conjecture. It might also show more clearly how colonisers exploit the colonised: indeed, some preliminary ancient inequality evidence suggests higher extraction ratios in colonised s than in autonomous societies. Unlike the findings regarding the evolution of the 20th century inequality in advanced economies, our ancient inequality sample does not reveal any significant correlation between the income share of the top 1 percent and overall inequality.