Search Results (69)

Classical epidemic models treat vaccine uptake as an exogenous parameter, yet real-world coverage emerges from strategic choices made by individuals facing uncertain risks. During the last two decades, vaccination games, which combine epidemic dynamics with game theory, behavioural economics, and network science, have become a very important tool for analysing this problem. Here, we synthesise more than 80 theoretical, computational, and empirical studies to clarify how population structure, psychological perception, pathogen complexity, and policy incentives interact to determine vaccination equilibria and epidemic outcomes. Papers are organised along five methodological axes: (i) population topology (well-mixed, static and evolving networks, multilayer systems); (ii) decision heuristics (risk assessment, imitation, prospect theory, memory); (iii) additional processes (information diffusion, non-pharmacological interventions, treatment, quarantine); (iv) policy levers (subsidies, penalties, mandates, communication); and (v) pathogen complexity (multi-strain, zoonotic reservoirs). Common findings across these studies are that voluntary vaccination is almost always sub-optimal; feedback between incidence and behaviour can generate oscillatory outbreaks; local network correlations amplify free-riding but enable cost-effective targeted mandates; psychological distortions such as probability weighting and omission bias materially shift equilibria; and mixed interventions (e.g., quarantine + vaccination) create dual dilemmas that may offset one another. Moreover, empirical work surveys, laboratory games, and field data confirm peer influence and prosocial motives, yet comprehensive model validation remains rare. Bridging the gap between stylised theory and operational policy will require data-driven calibration, scalable multilayer solvers, and explicit modelling of economic and psychological heterogeneity. This review offers a structured roadmap for future research on adaptive vaccination strategies in an increasingly connected and information-rich world. Full article

Under the “Dual Carbon” strategy, collaborative governance of port atmospheric pollutants and carbon emissions is critical for low-carbon transformation. Focusing on Ningbo-Zhoushan Port (48% regional ship emissions), this study examines government, port enterprises, and public interactions. A tripartite evolutionary game model with numerical simulation reveals dynamic patterns and key factors. The results show the following: (1) A substitution effect exists between government incentive costs and penalty intensity—increased environmental governance budgets reduce the probability of government incentives, whereas higher public reporting rewards accelerate corporate emission reduction convergence. (2) Public supervision exhibits cyclical fluctuations due to conflicts between individual rationality and collective interests, with excessive reporting rewards potentially triggering free-rider behavior. (3) The system exhibits two stable equilibria: a low-efficiency equilibrium (0,0,0) and a high-efficiency equilibrium (1,1,1). The latter requires policy cost compensation, corporate emission reduction gains exceeding investments, and a supervision benefit–cost ratio greater than 1. Accordingly, the study proposes a three-dimensional “Incentive–Constraint–Collaboration” governance strategy, recommending floating penalty mechanisms, green financial instrument innovation, and community supervision network optimization to balance environmental benefits with fiscal sustainability. This research provides a dynamic decision-making framework for multi-agent collaborative emission reduction in ports, offering both methodological innovation and practical guidance value. Full article

The diffusion of green energy technological innovation based on international green energy cooperation is a critical pathway to achieving global low-carbon emission reductions. However, few studies have considered the innovation diffusion pathways of green energy technologies under bilateral policy uncertainties. This paper constructs an evolutionary game model for the diffusion of green energy technological innovation in a complex network environment, with a focus on analyzing the impacts of key parameters such as policy spillover effects, technological heterogeneity, technical leakage risks, and free-riding risks on the equilibrium outcomes of evolutionary strategies. The results of the study are as follows: (1) Technological synergy and technological heterogeneity have a significant role in promoting the diffusion of green energy technological innovation, but when technological heterogeneity is too high, it is difficult for the two parties to find more common interests and areas of technological interaction, and the cooperative innovation will be turned into an empty shell that has a name but no reality. (2) Policy uncertainty has a significant impact on the diffusion of green energy technology innovation, and the specific impact depends on the type of policy, policy intensity, policy spillover effects, and other key parameters. (3) The risk of technological obsolescence has prompted countries to deeply participate in green energy international cooperation to realize the “curved road overtaking” of green energy technology based on technological locking and latecomer advantages; due to the existence of the phenomenon of “free-riding”, the logic of value creation based on win–win cooperation is replaced by the opportunism of “enjoying the benefits”, and cooperative innovation may be turned into a one-time “handshake agreement”. The existence of the risk of technology leakage can turn collaborative innovation into a “witch hunt” by the underdog against the overdog, and the diffusion process of green energy technology innovation is led in the wrong direction. Full article

The synergistic dilemma of upstream actors in the agro-ecological product supply chain restricts the transformation of ecological value, and traditional research focuses on the “production-supply” dichotomy, neglecting the driving role of the innovation service system. This study innovatively proposes a theoretical framework of “industry-supply-innovation tri-system synergy”, constructs a dynamic evolutionary game model with “free-riding” behavior, quantifies the effects of synergistic cost sharing coefficients (θ), benefit distribution ratios (γ), and policy regulation variables on the evolution of the main body’s strategy, and reveals the key laws through Matlab simulation. The results show that: (1) the participation of an innovation service system can significantly improve the speed of cooperation convergence; (2) the initial willingness to cooperate and the fairness of benefit distribution dominate the evolution path, and the probability of the system converging to “active cooperation” increases significantly when θ > 0.5; (3) the policy needs to be complemented with the market, and the government optimizes the distribution of the benefits of innovation services to improve the efficiency of the supply chain. The government can optimize the distribution of benefits from innovation services to promote the efficiency of the supply chain. Accordingly, we propose a “market-policy” dual-wheel control strategy to promote the deep integration of multiple supply chain actors with the innovation service system as a link. Full article

Simulating the experience of flight is a key objective of virtual reality (VR) technology. To enhance the sense of flying and immersion, we developed Drone Rider, a VR system that simulates free-flight atop a drone. In this study, we investigated whether delivering vibratory stimuli to the user’s feet could improve these sensations. While high-frequency drone propeller vibrations typically induce sensory numbness, alternative vibration patterns were explored. In Experiment 1, participants rated 13 different vibration patterns derived from various mechanical sounds, such as those from chainsaws, motorcycles, and washing machines. The motorcycle-based vibrations were most effective in enhancing both the sense of flight and immersion. In Experiment 2, we synthesized new vibration patterns by superimposing the highest-rated vibrations from Experiment 1, but no combination outperformed the original motorcycle vibration. These findings suggest that vibrations with multiple components below 100 Hz may reduce sensory adaptation and enhance the sense of flight and immersion in VR. This work provides valuable insights for developers aiming to optimize haptic feedback in VR flight simulators. Full article

Against the backdrop of an increasingly sound supply chain system and thriving e-commerce, it is becoming increasingly common for retailers to introduce their own brands of products and for manufacturers to open up direct online sales channels. The existence of these two supply chain decisions is complex and involves interactions. Moreover, the introduction of online direct sales channels will bring about differences in prices and service quality between channels, resulting in a free-riding effect on the internet. However, existing related research rarely considers the role of network free-riding effect in this supply chain system. This article integrates the network free-riding effect into the supply chain model by setting the network free-riding rate. According to whether retailers introduce their own brand products and manufacturers open up online direct sales channels, four supply chain scenarios are formed, and the reverse recursion method is used to obtain the profit functions for each of these four scenarios. Then, a Stackelberg game model is established to determine the response strategies of manufacturers and retailers based on the changes in profits of manufacturers caused by retailer decisions and the changes in profits of retailers caused by manufacturer decisions. Through analysis, it was discovered that a key factor affecting decision-making within the supply chain system is the retailer’s channel advantage. When the channel advantage of retailers is strong, manufacturers will open up online direct sales channels to weaken the channel advantage of retailers. Retailers will not introduce their own brand products but are more inclined to cooperate with manufacturers. When the channel advantage of retailers is weak, retailers will attract consumers and consolidate their channel advantage by introducing high-quality, low-priced private label products, while manufacturers will maintain cooperation with retailers and adopt a strategy of not opening up online direct sales channels. We also analyzed the Nash equilibrium state under different channel advantages of retailers. Full article

The collaborative promotion of agricultural green technology innovation and adoption (AGTIA) is essential for achieving green agriculture. However, there remains a need to raise both innovation and adoption levels, necessitating explorations of the effects of government subsidies and collaborative mechanisms. To this end, this paper builds an evolutionary game model to analyze the collaborative promotion of AGTIA. By introducing relevant parameters, such as government subsidies for AGTIA, dividends and liquidated damages within industrial technology innovation alliances (ITISAs), and cost reduction coefficients, this paper explores the impacts of the technology spillover effect, price premium of green agricultural products, and government subsidies on the strategic choices of related participants. The main findings are as follows: (1) The key factors influencing AGTIA are different and the government can implement different combinations of dynamic and static subsidy mechanisms at distinct stages of agricultural green development. Government subsidies play a major role at the initial stage, while ITISAs should take fuller advantage of AGTIA as green agriculture matures. (2) Increasing subsidies can promote AGTIA at the initial stage. However, an optimal range of subsidies exists, and when subsidies are higher than a certain threshold, government subsidy willingness fluctuations may lead to decreased stability. (3) There is a threshold of liquidated damages within ITISAs. Only when liquidated damages exceed the threshold can they facilitate the development of durable ITISAs and discourage free-rider behavior. The above findings can provide theoretical support for relevant government sectors when issuing policies to promote AGTIA and agricultural green development. Full article

With the profound integration of digital technology and traditional agriculture, the whole industry chain of rural e-commerce, as an advanced system, is reshaping the production, sales, and management models of agriculture and is emerging as a new catalyst for the advancement of digital agriculture through significant innovation. This paper focuses on the digital empowerment attributes and strategic attributes of the whole industrial chain of rural e-commerce, and evolutionary game models under market mechanisms and regulations are constructed. It examines the influence of various elements, such as the digital technology empowerment coefficient, on collaborative innovation within the whole industry chain of rural e-commerce. Using case simulations, this paper discusses the role of government regulation and intervention when market mechanisms are inadequate. The study reveals that factors such as the digital technology empowerment coefficient, technology absorptive capacity, and the amount of technology and information stored in collaborative innovation positively influence the whole industry chain. Potential risk losses and free-rider gains have negative effects on the evolution of the system toward collaborative innovation. When market mechanisms are inadequate, a combination of operational cost subsidies and incentive measures can yield more effective policy synergy, with the incentive impact of cost subsidies being particularly notable. The strategic application of enterprise-liquidated damage and government penalties will aid in regulating and directing corporate behavior. The findings of this research not only offer a new microlevel explanation for understanding the decision-making mechanism behind collaborative innovation in the whole industrial chain of rural e-commerce but also serve as a reference for government policy formulation to ensure the stability of the whole rural e-commerce industry chain. Full article

Credit purchase enables the manufacturers in the e-commerce environment to provide pre-sales service that consumers can experience first and pay later. This paper considers demand associated with price and green promotion service level and builds four decentralized game models to study two green promotion service allocation strategies and demand forecasting information sharing strategies in a dual-channel environment. The effects of the degree of dual-channel competition and free-riding on the perfect Bayesian Nash equilibrium are studied. The results show that the retailer should actively cooperate with the manufacturer and share private forecasting information if the coefficient of channel substitution is relatively high. Sharing information will aggravate double marginalization and hurt the retailer. In addition, the retailer’s profit is positively influenced by the forecasting accuracy in four models. When the manufacturer invests in the green promotion service, the prediction accuracy hurts the manufacturer’s profit without information sharing and there is a positive impact with information sharing. In particular, when a retailer provides service, we take the consumer’s free-riding behavior into account, and we find that free-riding hurts both parties and the whole supply chain. In addition, the manufacturer’s profit is irrelevant to the prediction accuracy without information sharing and positively influenced by the accuracy with information sharing. Full article

Collaborative edge intelligence, a distributed computing paradigm, refers to a system where multiple edge devices work together to process data and perform distributed machine learning (DML) tasks locally. Decentralized Internet of Things (IoT) devices share knowledge and resources to improve the quality of service (QoS) of the system with reduced reliance on centralized cloud infrastructure. However, the paradigm is vulnerable to free-riding attacks, where some devices benefit from the collective intelligence without contributing their fair share, potentially disincentivizing collaboration and undermining the system’s effectiveness. Moreover, data collected from heterogeneous IoT devices may contain biased information that decreases the prediction accuracy of DML models. To address these challenges, we propose a novel incentive mechanism that relies on time-dependent blockchain records and multi-access edge computing (MEC). We formulate the QoS problem as an unbounded multiple knapsack problem at the network edge. Furthermore, a decentralized valuation protocol is introduced atop blockchain to incentivize contributors and disincentivize free-riders. To improve model prediction accuracy within latency requirements, a data scheduling algorithm is given based on a curriculum learning framework. Based on our computer simulations using heterogeneous datasets, we identify two critical factors for enhancing the QoS in collaborative edge intelligence systems: (1) mitigating the impact of information loss and free-riders via decentralized data valuation and (2) optimizing the marginal utility of individual data samples by adaptive data scheduling. Full article

Cooperation is essential for the survival of human society. Understanding the nature of cooperation and its underlying mechanisms is crucial for studying human behavior. This paper investigates the impact of leadership on public cooperation by employing repeated sequential public goods games, as well as by examining whether leading by example (through rewards and punishments) can promote cooperation and organizational success. The leaders were assigned randomly and were given the authority to reward or punish. As a result, (1) the leaders showed a strong tendency toward reciprocity by punishing free riders and rewarding cooperators at their own expense, which enhanced the intrinsic motivation for others to follow their example; and (2) both rewards and punishments were effective in promoting cooperation, but punishment was more effective in sustaining a high level of collaboration. Additionally, leaders preferred using rewards and were more reluctant to use punishments. These findings are crucial for creating organizational structures that foster cooperation. Full article

Healthcare is considered one of the necessities for sustaining life. However, frequent emergencies raise the risk of supply chain disruption, seriously threatening people’s lives and health security. Therefore, building a resilient healthcare supply chain is an important initiative to manage the healthcare crisis effectively. Based on the secondary supply chain formed by medical supply manufacturers and retailers, this paper constructs an evolution game model of resilience investment decisions under the non-disruption and disruption symmetry scenarios of the supply chain and analyzes the stabilization strategies employed by both parties based on their asymmetry strategy choices. Subsequently, the numerical simulation is used to analyze the impact of various parameters on the evolutionary results and their evolutionary trends. The results of the study show that additional benefits from resilience investment, potential costs, disruption losses, market encroachment revenue, “free-rider” benefits, additional benefit increase coefficient, resilience investment reduction coefficient, disruption loss reduction coefficient, additional unit cost reduction coefficient, and market encroachment revenue coefficient all influence the resilience investment decisions. Finally, based on the simulation results, specific recommendations are formulated to improve the resilience of the healthcare supply chain. Full article

A common practice in inventory systems with several customers requiring differentiated service levels is to group them into two or three classes, where a customer class is a group of customers with the same preset service level in terms of product availability. However, there is no evidence that grouping customers into two or three classes is optimal in terms of the ordering policy parameters. This paper studies the effect of the number of customer classes on the inventory level of a single-period inventory system with stochastic demand and individual service-level requirements from multiple customer classes. Using a Sample Average Approximation approach, we formulate computationally tractable multi-class service level models, under responsive and anticipative priority policies in cases of shortage, as mixed integer linear problems (MIPs). The effect of the number of classes on the inventory level is determined using a round-up aggregation scheme; i.e., given a sufficiently large initial number of classes, it is reduced by adding the lower service level classes to the next higher class. We analytically characterize the optimal inventory level under responsive and anticipative priority policies as a function of the initial number of classes and the number of classes grouped based on the round-up aggregation scheme. Under a responsive priority policy, we show that there is an optimal number of classes, while under an anticipative priority policy, the optimal number of classes is equal to the initial number of classes. The effect of free-riders resulting from the round-up aggregation scheme on the optimal inventory level is studied through numerical experiments. Full article

Major projects are the important platform for enhancing a country’s comprehensive national power and strengthening its capacity for independent innovation. Although major projects in China have made remarkable achievements, willingness to cooperate and innovate has not achieved the desired target. In this paper, the evolutionary game model of cooperative innovation behavior of general contractors and subcontractors is constructed by considering reputational factors. Through theoretical derivation, the influence of the distribution ratio of collaborative innovation benefit, spillover technology absorption capacity, and reputation discounting coefficient on innovation behavior is analyzed. Finally, MATLAB software is used to simulate the dynamic evolution process of strategy selection. The results show that (1) a reasonable benefit distribution coefficient can promote the evolution of innovation behavior in a positive direction; (2) both the reduction of innovation cost and the increase of spillover technology absorption capacity can make the innovation subject more inclined to choose the active collaborative innovation strategy; and (3) it is the higher-than-threshold reputation loss that can effectively inhibit the “free-rider” behavior. The research conclusions and managerial implications can provide reference for improving the willingness to cooperate in major projects’ technology innovation. Full article

“Paying it forward” is a behavior in which people help someone else because they were helped in the past. Although experimental evidence exists that indicates that real human beings often “pay-it-forward” even in the face of free-rider risks, the theoretical basis for the evolution of this behavior remains unclear. In this paper, we propose a game-theoretical model that explains how pay-it-forward behavior can evolve despite the temptation to free-ride. By assuming that human beings exhibit cognitive distortions, as predicted by prospect theory, and that free-riding is punished with a tiny probability, we demonstrate that pay-it-forward, alongside unconditional altruistic behavior, can evolve and effectively deter free-riding behavior. Full article