Near universal values of social inequality indices in self-organized critical models

TL;DR

This study finds that diverse self-organized critical models exhibit nearly universal social inequality indices, indicating broad similarity in inequality measures across different systems and potential links to socio-economic data.

Contribution

It demonstrates that different self-organized critical models share nearly universal inequality index values, revealing a commonality in emergent inequality near critical states.

Findings

Gini and Kolkata indices are nearly universal across models.

Self-organized critical systems show broad similarity in inequality measures.

Emergent inequality may be linked to proximity to critical states.

Abstract

We have studied few social inequality measures associated with the sub-critical dynamical features (measured in terms of the avalanche size distributions) of four self-organized critical models while the corresponding systems approach their respective stationary critical states. It has been observed that these inequality measures (specifically the Gini and Kolkata indices) exhibit nearly universal values though the models studied here are widely different, namely the Bak-Tang-Wiesenfeld sandpile, the Manna sandpile and the quenched Edwards-Wilkinson interface, and the fiber bundle interface. These observations suggest that the self-organized critical systems have broad similarity in terms of these inequality measures. A comparison with similar earlier observations in the data of socio-economic systems with unrestricted competitions suggest the emergent inequality as a result of the possible proximity to the self-organized critical states.