Fig. 2: Development of inequality in relational wealth between the members of the upper societal segment using time intervals of 200 years.

The red and black lines connecting inequality estimates and the shares of individuals buried in burial mounds for consecutive time slices are linear interpolations and not actual observations. A “x” on top of each line connecting the inequality estimates indicates if the difference in the estimates between two periods is statistically significant (p-value < 0.1). In contrast, a “o” indicates a statistically insignificant difference (p-value ≥ 0.1). The numbers on top of the inequality estimates show the sample size. The green bars represent the sum of buried individuals (burial mounds, flat graves, and collective graves) in the respective time intervals captured by our data. The black line displays the share of individuals buried in burial mounds, which gives us an idea about the relative size of the population’s upper societal segment and social mobility and structures. SI, Sections 4 and 7 contain the numerical results for this figure.