Inferring inequality in prehistoric societies from grave sizes: a methodological framework

Abstract

Although there is little question that societal scale and mode of production from foraging to farming correlate with increases in economic inequality, there is no consensus over the relative importance of those factors or the role of institutions in the variance of inequality across time and space. To better understand the dynamics of economic inequality, it is necessary to expand our analytical horizon beyond the present into the deeper past. However, an analytical protocol especially oriented towards the systematic study of economic inequality with archaeological data is lacking. Here we propose the utility of grave size as a reliable proxy for estimating prehistoric social inequality and provide a methodological framework for analyzing this type of data. Our case studies using grave-size data from two Neolithic settlements in North and East China suggest that the asymmetric double Pareto distribution can be used as an alternative model to fit to the size distribution of grave wealth usually skewed and long-tailed. Based on the analytical connection between the probability density function and the Lorenz curve, a parsimonious algebraic expression of the Gini coefficient was derived. This analytical protocol also can serve as a convenient tool for quantifying economic inequality in prehistoric societies using other types of archaeological data such as land and house areas.