Suchergebnisse

M.C. was supported by the Spanish Ministry of Science, Andalusian Government, University of Granada, and ERDF under grants SIMARK (P18-TP-4475) , RYC-2016-19800, and PPJIA2020-09 (TURCOMPLEX) . J.H. was supported by the University of Las Palmas de Gran Canaria, under grant COVID-19 04. M.P. was supported by the Slovenian Research Agency (Grant Nos. P1-0403 and J1-2457) . Funding for open access charge: Universidad de Granada/CBUA. ; Many countries worldwide rely on tourism for their economic well-being and development. But with issues such as over-tourism and environmental degradation looming large, there is a pressing need to determine a way forward in a sustainable and mutually rewarding manner. With this motivation, we here propose an asymmetric evolutionary game with mobility where local stakeholders and tourists can either cooperate or defect in a spatially structured setting. Our study reflects that sustainable tourism is primarily determined by an optimal trade-off between economic benefits of the stakeholders and their costs related to the application of sustainability policies. In contrast, the specific benefits and costs of the tourists are comparatively less relevant. The reader can also observe that allowing for greater tourist mobility decreases cooperation and leads to faster polarization among local stakeholders. In agreement with observations worldwide, we identify decreasing population densities in tourist areas in terms of both, stakeholders and tourists, to be a key aid to greater cooperation and overall sustainability of tourism. These results are rooted in spatial formations and complex alliances that manifest spontaneously through the evolutionary dynamics in a structured population. ; Spanish Ministry of Science, Andalusian Government, University of Granada ; European Commission P18-TP-4475 RYC-2016-19800 PPJIA2020-09 ; University of Las Palmas de Gran Canaria COVID-19 04 ; Slovenian Research Agency - Slovenia P1-0403 J1-2457 ; Universidad de Granada/CBUA

M.C. is supported by the Spanish Ministry of Science, An-dalusian Government, and ERDF under grants SIMARK (P18-TP-4475) , RYC-2016-19800, PPJIA2020-09 (TURCOMPLEX) , and Jose Castillejo program (CAS19/00090) . J.M.H. is supported by the University of Las Palmas de Gran Canaria under grant COVID-19 04. F.C.S. acknowledges the support from FCT-Portugal (grants UIDB/50021/2020, PTDC/MAT-APL/6804/2020, and PTDC/CCI-INF/7366/2020) . Funding for open access charge: Universidad de Granada/CBUA. ; The spread of COVID-19 and ensuing containment measures have accentuated the profound interdepen- dence among nations or regions. This has been particularly evident in tourism, one of the sectors most affected by uncoordinated mobility restrictions. The impact of this interdependence on the tendency to adopt less or more restrictive measures is hard to evaluate, more so if diversity in economic exposures to citizens' mobility are considered. Here, we address this problem by developing an analytical and com- putational game-theoretical model encompassing the conflicts arising from the need to control the eco- nomic effects of global risks, such as in the COVID-19 pandemic. The model includes the individual costs derived from severe restrictions imposed by governments, including the resulting economic interdepen- dence among all the parties involved in the game. By using tourism-based data, the model is enriched with actual heterogeneous income losses, such that every player has a different economic cost when ap- plying restrictions. We show that economic interdependence enhances cooperation because of the decline in the expected payoffs by free-riding parties (i.e., those neglecting the application of mobility restric- tions). Furthermore, we show (analytically and through numerical simulations) that these cross-exposures can transform the nature of the cooperation dilemma each region or country faces, modifying the position of the fixed points and the size of the basins of attraction that characterize this class of games. Finally, our results suggest that heterogeneity among regions may be used to leverage the impact of intervention policies by ensuring an agreement among the most relevant initial set of cooperators. ; Spanish Ministry of Science, An-dalusian Government ; European Commission SIMARK (P18-TP-4475) RYC-2016-19800 ; Jose Castillejo program ; University of Las Palmas de Gran Canaria ; Portuguese Foundation for Science and Technology European Commission UIDB/50021/2020 PTDC/MAT-APL/6804/2020 ; Universidad de Granada/CBUA PPJIA2020-09 CAS19/00090 COVID-19 04 PTDC/CCI-INF/7366/2020

S.D. would like to acknowledge the support of an Australian Government Research Training Program scholarship to study a PhD degree in Computer Science at the University of Newcastle, Australia, supervised by R.C. ; We present an evolutionary game model that integrates the concept of tags, trust and migration to study how trust in social and physical groups influence cooperation and migration decisions. All agents have a tag, and they gain or lose trust in other tags as they interact with other agents. This trust in different tags determines their trust in other players and groups. In contrast to other models in the literature, our model does not use tags to determine the cooperation/defection decisions of the agents, but rather their migration decisions. Agents decide whether to cooperate or defect based purely on social learning (i.e. imitation from others). Agents use information about tags and their trust in tags to determine how much they trust a particular group of agents and whether they want to migrate to that group. Comprehensive experiments show that the model can promote high levels of cooperation and trust under different game scenarios, and that curbing the migration decisions of agents can negatively impact both cooperation and trust in the system.We also observed that trust becomes scarce in the system as the diversity of tags increases. This work is one of the first to study the impact of tags on trust in the system and migration behaviour of the agents using evolutionary game theory. ; Australian Government ; Department of Industry, Innovation and Science

This paper fills a gap in the existing literature by answering the following question: is the effect of envy on people's intention to share information the same in offline settings and on online social networks? Two studies demonstrate (1) how envy that results from upward social comparisons affects people's intention to share information and (2) the difference between online and offline settings. The likelihood of sharing information susceptible of triggering envy is lower on online social networks than in an offline scenario. In digital environments, feelings of envy depend on the number of social comparisons that the individual is exposed to. This research recommends (a) incorporating tools that allow online social network users to feel part of their network's successes, (b) promoting offline diffusion of information, and (c) encouraging people to play an active role when using online social networks. To date the literature has paid no attention to envy as an engine of information sharing. This aspect is especially relevant when discussing platforms whose main goal is precisely information sharing and that offer fertile ground for upward social comparisons. ; The authors would like to thank the Ramón Areces Commercial Distribution Chair for financing a mobility grant of Dr. Suárez a visiting scholar at the Robert H. Smith School of Business of the University of Maryland on early stages of this project. Dr. Chica was supported by the Ramón y Cajal program [RYC‐2016‐19800]. This work was also supported by the project SIMARK [PY18‐TP‐4475] granted by the Andalusian Government and by the University of Oviedo [PAPI‐19‐EMERG‐15].

This work was supported by the Spanish Agencia Estatal de Investigacion, the Andalusian Government, the University of Granada, and European Regional Development Funds (ERDF) under Grants EXASOCO (PGC2018-101216-B-I00), SIMARK (P18-TP-4475), and AIMAR (A-TIC-284-UGR18). Manuel Chica was also supported by the Ramon y Cajal program (RYC-2016-19800). ; The authors would like to thank the ``Centro de Servicios de Informática y Redes de Comunicaciones'' (CSIRC), University of Granada, for providing the computing resources (Alhambra supercomputer). ; Complex problems can be analyzed by using model simulation but its use is not straight-forward since modelers must carefully calibrate and validate their models before using them. This is specially relevant for models considering multiple outputs as its calibration requires handling different criteria jointly. This can be achieved using automated calibration and evolutionary multiobjective optimization methods which are the state of the art in multiobjective optimization as they can find a set of representative Pareto solutions under these restrictions and in a single run. However, selecting the best algorithm for performing automated calibration can be overwhelming. We propose to deal with this issue by conducting an exhaustive analysis of the performance of several evolutionary multiobjective optimization algorithms when calibrating several instances of an agent-based model for marketing with multiple outputs. We analyze the calibration results using multiobjective performance indicators and attainment surfaces, including a statistical test for studying the significance of the indicator values, and benchmarking their performance with respect to a classical mathematical method. The results of our experimentation reflect that those algorithms based on decomposition perform significantly better than the remaining methods in most instances. Besides, we also identify how different properties of the problem instances (i.e., the shape of the feasible region, the shape of the Pareto front, and the increased dimensionality) erode the behavior of the algorithms to different degrees. ; Spanish Agencia Estatal de Investigacion ; Andalusian Government ; University of Granada ; European Commission PGC2018-101216-B-I00 P18-TP-4475 A-TIC-284-UGR18 ; Spanish Government RYC-2016-19800

This paper simulates the effect of the strategies implemented by politicians after the terrorists attacks in Madrid on 11 March 2004 on the ideological distance between voters and political parties. The attacks took place three days before the elections and changed the campaign's agenda, which centered around the issue of who was responsible for the attack: ETA or Al Qaeda. It also altered the agenda of the mass media, which focused its informative activity on broadcasting news related to this issue. We did an exhaustive selection process of all the news broadcast on television, radio, and newspapers that made reference to the authorship of the attack. Using these messages we developed an agent-based model for explaining how the political strategies implemented by political parties influenced the ideological distance. The proposed model is based on the ideological proximity model by Downs (1957). After calibrating and validating the model with real data, we simulated the effect of three political strategies from the theory of terror management on the ideological distance between voters and political parties: the rally around the flag, the opinion leadership, and the priming of public opinion and media coverage. The results show that these strategies have a significant and stable impact on the ideological distance. In particular, the rally around the flag can have a lasting effect, capable of changing the ideological distance in the short term after a terrorist attack. ; Spanish Agencia Estatal de Investigacion, ´ the Andalusian Government, the University of Granada, and European Regional Development Funds (ERDF) under grants EXASOCO (PGC2018-101216-B-I00), SIMARK (P18-TP-4475), and AIMAR (A-TIC-284-UGR18). ; Project I + D+i from the FEDER Operational Program, Andalusia (A-SEJ-154- UGR18) ; Universidad de Granada / CBUA

We would like to thank Michael Maes and the anonymous reviewers for their insightful and constructive feedback. The first author, H. K. Nguyen, would like to acknowledge support from an Australian Government Research Training Program scholarship to study a PhD degree in Computer Science at The University of Newcastle, Australia. R. Chiong is the corresponding author of this paper. The third author, M. Chica, is supported through the Ramón y Cajal program (RYC-2016-19800) ; In this paper, we use agent-based modeling (ABM) to study different obstacles to the expansion of contract rice farming in the context of Mekong Delta (MKD)'s rice supply chain. ABM is a bottom-up approach for modeling the dynamics of interactions among individuals and complex combinations of various factors (e.g., economic, social or environmental). Our agent-based contract farming model focuses on two critical components of contractual relationship, namely financial incentives and trust. We incorporate the actual recurrent fluctuations of spot market prices, which induce both contractor and farmer agents to renege on the agreement. The agent-based model is then used to predict emergent system-wide behaviors and compare counterfactual scenarios of different policies and initiatives on maintaining the contract rice farming scheme. Simulation results firstly show that a fully-equipped contractor who opportunistically exploits a relatively small proportion (less than 10%) of the contracted farmers in most instances can outperform spot market-based contractors in terms of average profit achieved for each crop. Secondly, a committed contractor who offers lower purchasing prices than the most typical rate can obtain better earnings per ton of rice as well as higher profit per crop. However, those contractors in both cases could not enlarge their contract farming scheme, since either farmers' trust toward them decreases gradually or their offers are unable to compete with the benefits from a competitor or the spot market. Thirdly, the results are also in agreement with the existing literature that the contract farming scheme is not a cost-effective method for buyers with limited rice processing capacity, which is a common situation among the contractors in the MKD region. These results yield significant insights into the difficulty in expanding the agricultural contracting program in the MKD's rice supply chain. ; Ramón y Cajal program (RYC-2016-19800)