This project is an interactive agent-based model simulating consumption of a shared, renewable resource using a game-theoretic framework with environmental feedback. Although its original use was to simulate a ToC scenario with water as the shared resource, it can be applicable for a variety of scenarios including simulating climate disasters, environmental sensitivity to resource consumption, or influence of environmental degradation to agent behaviour. The primary goal of the model is to explore the socio-environmental feedback loops that lead to complex emergent system dynamics. It was inspired by the Weitz et. al. (2016, https://pubmed.ncbi.nlm.nih.gov/27830651/) use of environmental feedback in their paper, as well as the Demographic Prisoner’s Dilemma on a Grid model (https://mesa.readthedocs.io/stable/examples/advanced/pd_grid.html#demographic-prisoner-s-dilemma-on-a-grid). The main innovation of this model is the added environmental feedback with local resource replenishment.

Beyond its theoretical insights into coevolutionary dynamics, this ABM serves as a versatile tool with several practical applications. For urban planners and policymakers, the model can function as a ”digital sandbox” for testing the impacts of locating high-consumption industrial agents, such as data centers, in proximity to residential communities. It allows for the exploration of different urban densities, and the evaluation of policy interventions—such as taxes on defection or subsidies for cooperation—by directly modifying the agents’ resource consumptions to observe effects on resource health. Furthermore, the model provides a framework for assessing the resilience of such socio-environmental systems to external shocks.

The model is built using Mesa 1.2.1 for the model and Solara for the interactive web-based dashboard. While Mesa version 3.0 was available at the time of this project’s finalization, version 1.2.1 was used to ensure functional correctness and maintain compatibility. Initial testing with Mesa 3.0 revealed significant, non-backward-compatible API changes relative to the 1.x series, which would have required a substantial rewrite of the existing, validated codebase. Therefore, to guarantee the stability and reproducibility of the results based on the original model implementation, version 1.2.1 was retained as the foundational dependency for this research.

Model on the use of shared renewable resources including impact of imitation via success-bias and altruistic punishment.
The model is discussed in Introduction to Agent-Based Modeling by Marco Janssen. For more information see https://intro2abm.com/

REHAB has been designed as an ice-breaker in courses dealing with ecosystem management and participatory modelling. It helps introducing the two main tools used by the Companion Modelling approach, namely role-playing games and agent-based models.

This is a simple model replicating Hardin’s Tragedy of the Commons using reactive agents that have psychological behavioral and social preferences.

MASTOC is a replication of the Tragedy of the Commons by G. Hardin, programmed in NetLogo 4.0.4, based on behavioral game theory and Nash solution.