Tax thresholds yield multiple optimal cooperation levels in the spatial public goods game

Area of Science:

• Evolutionary Game Theory
• Socioeconomics
• Computational Social Science

Background:

• Income redistribution is vital for societal cooperation, with tax-based systems historically promoting cooperative incentives.
• Traditional tax systems apply universally, but this study explores a nuanced approach with income-based tax thresholds.

Purpose of the Study:

• To investigate the impact of tax rates and tax thresholds on the evolution of cooperation within a spatial public goods game.
• To analyze how varying tax thresholds influence cooperation dynamics under different tax rate conditions.

Main Methods:

• Utilized the spatial public goods game model to simulate cooperation dynamics.
• Conducted extensive numerical simulations varying tax rates and introducing a tax threshold for taxation.
• Employed evolutionary snapshots and quantitative analyses to understand the mechanisms of cooperation.

Main Results:

• Tax thresholds exhibit complex effects on cooperation, contingent on tax rates; low tax rates reveal multiple effective threshold intervals.
• Cooperation collapses if the tax threshold exceeds a critical level, irrespective of the tax rate.
• Self-organized redistribution forms protective layers around cooperative clusters, narrowing income gaps and enhancing cooperative advantage.

Conclusions:

• Tax thresholds are pivotal in modulating income redistribution's effect on cooperation, offering nuanced control over cooperative outcomes.
• The study underscores the critical role of carefully designed tax thresholds in sustaining and promoting cooperation in human societies.