Effects of inequality on a spatial evolutionary public goods game

Over the past decade, inequality has become one of the most complex and troubling challenges in the global economy. Many scientists are determined to eliminate inequality to achieve full cooperation. However, our research shows that not all inequalities hinder cooperation. In this article, we study the effects of inequality by introducing the disassortative mixing of the investment amount and enhancement factor assigned to certain individuals in the public goods game. Compared with the traditional version, we find that cooperation can be effectively promoted by aligned inequality, which means that individuals with the highest (lowest) investment capabilities contribute the greatest (lowest) investment amounts. The promotion of cooperation mainly depends on the heterogeneous contribution ability of players. Specifically, cooperators with high contribution ability can maximize collective benefits, causing cooperators with low contribution ability to form compact clusters and resist invasion by defectors. Our research indicates that the diversity of individual endowment and productivity may have a non-negligible influence on the evolution of cooperation among selfish individuals. The frequency of cooperation $$\rho _{c}$$ as a function of the enhancement factor r for different correlation coefficients.