Congestion phenomena caused by matching pennies in evolutionary games

Evolutionary social dilemma games are extended by an additional matching-pennies game that modifies the collected payoffs. In a spatial version players are distributed on a square lattice and interact with their neighbors. Firstly, we show that the matching-pennies game can be considered as the microscopic force of the Red Queen effect that breaks the detailed balance and induces eddies in the microscopic probability currents if the strategy update is analogous to the Glauber dynamics for the kinetic Ising models. The resulting loops in probability current breaks symmetry between the chessboard-like arrangements of strategies via a bottleneck effect occurring along the four-edge loops in the microscopic states. The impact of this congestion is analogous to the application of a staggered magnetic field in the Ising model, that is, the order-disorder critical transition is wiped out by noise. It is illustrated that the congestion induced symmetry breaking can be beneficial for the whole community within a certain region of parameters.Comment: 7 pages, 6 figure

Evaluating Outside the Box: An Alternative Framework for Analysing Social Protection Programmes

The evidence base on social protection programmes is expanding rapidly, largely pointing towards their positive impacts. Most evaluations rely heavily on quantitative techniques and experimental methods to allow for attribution of impacts. In this paper, we argue that new ways of investigation and analysis are needed to expand and deepen the evidence base in support of improved design and implementation of social protection. Greater emphasis on qualitative research, mixed methods and participatory evaluation is crucial, given current evidence gaps about programme dynamics and impacts. This paper proposes a new evaluation framework that goes beyond conventional approaches, by highlighting relatively neglected aspects related to programme processes, social dynamics and feedback loops in programme evaluations

Eco-evolutionary dynamics with environmental feedback: cooperation in a changing world

Eco-evolutionary game dynamics which characterizes the mutual interactions and the coupled evolutions of strategies and environments has been of growing interests in very recent years. Since such feedback loops widely exist in a range of coevolutionary systems, such as microbial systems, social-ecological system and psychological-economic system, recent modeling frameworks that unveil the oscillating dynamics of social dilemmas have great potential for practical applications. In this perspective article, we overview the latest progress of evolutionary game theory in this direction. We describe both mathematical methods and interdisciplinary applications across different fields. The ideas worthy of further consideration are discussed in prospects, with the central role of promoting cooperations in a changing world

Exploring Agricultural Production Systems and Their Fundamental Components with System Dynamics Modelling

Agricultural production in the United States is undergoing marked changes due to rapid shifts in consumer demands, input costs, and concerns for food safety and environmental impact. Agricultural production systems are comprised of multidimensional components and drivers that interact in complex ways to influence production sustainability. In a mixed-methods approach, we combine qualitative and quantitative data to develop and simulate a system dynamics model that explores the systemic interaction of these drivers on the economic, environmental and social sustainability of agricultural production. We then use this model to evaluate the role of each driver in determining the differences in sustainability between three distinct production systems: crops only, livestock only, and an integrated crops and livestock system. The result from these modelling efforts found that the greatest potential for sustainability existed with the crops only production system. While this study presents a stand-alone contribution to sector knowledge and practice, it encourages future research in this sector that employs similar systems-based methods to enable more sustainable practices and policies within agricultural production

Regimes and Resilience in the Modern Global Food System

Much public discourse surrounding the modern global food system operates on the assumption of the primary agency of individual consumers in ensuring an equitable and sustainable food supply. However, this approach fails to account for the larger structural forces of the system which frame the limits of how we interact with and are affected by our food system. Taking a closer look at the global economic, political, cultural, and environmental forces that have collectively shaped historical food regimes reveals the deeper structural patterns that currently determine how we produce, distribute, and consume food around the world. Due to the underlying structural processes of increasing distancing and standardization, we have become highly disembedded from our food system and will need to look for clues from past periods of transition between food regimes to better position ourselves to work towards a global restructuring of, and human reembedding in, the modern global food system