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on Network Economics |
| By: | Elena Panova (TSE-R - Toulouse School of Economics - UT Capitole - Université Toulouse Capitole - UT - Université de Toulouse - EHESS - École des hautes études en sciences sociales - CNRS - Centre National de la Recherche Scientifique - INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement); Thibault Laurent (TSE-R - Toulouse School of Economics - UT Capitole - Université Toulouse Capitole - UT - Université de Toulouse - EHESS - École des hautes études en sciences sociales - CNRS - Centre National de la Recherche Scientifique - INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement) |
| Abstract: | This paper examines how the structure of communication networks influences learning and social welfare when participants have different prior opinions and face uncertainty about an external state. We analyze a game in which players form links to exchange opinions on the state and reduce their uncertainty. The players hold imperfectly correlated subjective priors on the state. Therefore, their opinions transmit their private signals with frictions, termed interpretation noise. Network clustering facilitates learning by eliminating this interpretation noise. Therefore, the egalitarian efficient network is: a complete component if the interpretation noise is sufficiently high, and a flower otherwise. This network constitutes a Nash equilibrium. These findings establish a link between a key feature of social networks (clustering) and the quality of learning through network communication, offering a potential explanation for the prevalence of clustering in real-world social networks. |
| Keywords: | Network formation, Clustering, Differentiated priors |
| Date: | 2025–05–12 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05096724 |
| By: | Marc-Antoine Faure; César Ducruet |
| Abstract: | Once developed by geographers, shipping network research has long remained a peripheral subfield of academia. Increased shipping data availability and computational power, combined with renewed graph-theoretical methods, caused an unprecedented growth of shipping network studies since the late 2000s. This article provides an in-depth bibliometric analysis of no less than 329 peer-reviewed papers published between 2007 and 2025. First, it describes the gathered corpus from diverse angles, such as the growth of papers, the main journals, its disciplinary background, and the pattern of co-authorships. Second, we use a natural language processing (NLP) approach, namely the structural topic model, to undertake an in-depth analysis based on the contents of abstracts. We identify four main topics, of which trade and connectivity; hubs and centrality; vulnerability and robustness; and communities and spatial structure, which are discussed according to their innovative character compared with wider research on ports, maritime transport, and network science. Three additional subgroups received peripheral attention despite their core importance: environmental issues (of which, marine bioinvasions), socio-economic development, and the role of shipping alliances. We conclude that network science methods still have important potential in shipping network port and maritime studies, and propose several pathways for further research. |
| Keywords: | bibliometric analysis; complex networks; graph theory; maritime transport; scientometrics; shipping network; social network analysis; structural topic modeling |
| JEL: | R41 F10 |
| Date: | 2025 |
| URL: | https://d.repec.org/n?u=RePEc:drm:wpaper:2025-27 |
| By: | Christophe Bravard (GAEL - Laboratoire d'Economie Appliquée de Grenoble - CNRS - Centre National de la Recherche Scientifique - INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement - UGA - Université Grenoble Alpes - Grenoble INP - Institut polytechnique de Grenoble - Grenoble Institute of Technology - UGA - Université Grenoble Alpes); Jacques Durieu (CREG - Centre de recherche en économie de Grenoble - UGA - Université Grenoble Alpes); Sudipta Sarangi (Virginia Tech [Blacksburg]); Corinne Touati (Centre Inria de l'Université Grenoble Alpes - Inria - Institut National de Recherche en Informatique et en Automatique) |
| Abstract: | We study influence competition between two players: a designer who can shape the pattern of interaction between a set of agents and influence them, and an adversary who can counter-influence these agents. Creating the network and influencing agents are both costly activities for the two players. The final opinion and the vote of the agents depend on how the two players influence them as well as the opinion of their neighbors. Agent votes determine the payoffs of the two players and to win the designer must obtain the vote of all the agents. We begin by assuming that the designer has the better influence technology, and subsequently relax this assumption. We find that optimal strategies depend on the different costs incurred by the players, as well as who has the advantage in influence technology. We also study what happens when links between agents can arise randomly with a known exogenous probability, taking away some of the designer's control over the network. We provide conditions under which the results of the benchmark model are preserved. Next, we modify two additional assumptions: (1) requiring the designer to only secure a majority of the votes, and (2) allowing the agents interact for several rounds before casting the final vote. In both cases, the designer needs fewer resources to win the game. |
| Abstract: | Nous étudions la compétition d'influence entre deux joueurs : un concepteur qui peut façonner le modèle d'interaction entre un ensemble d'agents et les influencer, et un adversaire qui peut contre-influencer ces agents. La création du réseau et l'influence des agents sont des activités coûteuses pour les deux joueurs. L'opinion finale et le vote des agents dépendent de la manière dont les deux joueurs les influencent ainsi que de l'opinion de leurs voisins. Les votes des agents déterminent les gains des deux joueurs et, pour gagner, le concepteur doit obtenir le vote de tous les agents. Nous commençons par supposer que le concepteur dispose de la meilleure technologie d'influence, puis nous assouplissons cette hypothèse. Nous montrons que les stratégies optimales dépendent des différents coûts encourus par les joueurs, ainsi que de l'identité de l'agent qui a la meilleure technologie d'influence. Nous étudions également ce qui se passe lorsque les liens entre les agents peuvent apparaître de manière aléatoire avec une probabilité exogène connue, ce qui enlève au concepteur une partie de son contrôle sur le réseau. Nous fournissons des conditions sous lesquelles les résultats du modèle de référence sont préservés. Ensuite, nous modifions deux hypothèses supplémentaires hypothèses supplémentaires : (1) exiger que le concepteur n'obtienne qu'une majorité des votes, et (2) permettre aux agents d'interagir pendant plusieurs tours avant de procéder au vote final. Dans les deux cas, le concepteur a besoin de moins de ressources pour gagner le jeu. |
| Keywords: | Network design, Opinion dynamics, Influence networks |
| Date: | 2024–07–23 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-04733885 |
| By: | Hana Krakovsk\'a; Rudolf Hanel |
| Abstract: | Asymmetric evolutionary games, such as the Ultimatum Game, provide keys to understanding the emergence of fairness in social species. Building on this framework, we explore the evolution of social value systems and the operational role that social status plays in hierarchically organised societies. Within the asymmetric Ultimatum Game paradigm, where "proposers" suggest terms for resource distribution, and "responders" accept or reject these terms, we examine the assignment of roles between players under a subjective social order. This order is grounded in an emergent status hierarchy based on observable player attributes (such as age and wealth). The underlying rules for constructing such a hierarchy stabilise over time by inheritance and family ties. Despite their subjective nature these (often sub-conscious) value systems have operative meaning in controlling access of individuals to resources and decision making. We demonstrate these effects using a simple but sufficiently complex model with dynamical population size and network structure, where division of resources (prey) is carried out according to the principles of the Ultimatum Game. We focus on the emerging proposer and responder thresholds under distinct social hierarchies and interaction networks and discuss them in relation to the extensive body of Ultimatum Game experiments conducted across a wide range of cultural contexts. We observe the emergence of diverse sharing norms, ranging from unfair to highly generous, alongside the development of various social norms. |
| Date: | 2025–05 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2505.07060 |
| By: | Eric Gao |
| Abstract: | I study how a startup with uncertainty over product quality and no knowledge of the underlying diffusion network optimally chooses initial seeds. To ensure widespread adoption when the product is good while minimizing negative perceptions when it is bad, the optimal number of initial seeds should grow logarithmically with network size. When there are agents of different types that govern their connectivity, it is asymptotically optimal to seed agents of a single type: the type that minimizes the marginal cost per probability of making the product go viral. These results rationalize startup behavior in practice. |
| Date: | 2025–06 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2506.10340 |
| By: | Adrián Fernandez-Perez (Michael Smurfit Graduate Business School, University College Dublin, Ireland.); Marta Gómez-Puig (Department of Economics and Riskcenter, Universitat de Barcelona, Spain.); Simón Sosvilla-Rivero (Complutense Institute for Economic Analysis, Universidad Complutense de Madrid, Spain.) |
| Abstract: | The sovereign debt crisis in the euro area revealed that European Monetary Union (EMU) government bond markets interact in a highly synchronised network and that risk particular to a country or sovereign bond yield component cannot be appropriately evaluated in isolation without taking potential risk transmission effects from other countries or sovereign bond yield components into consideration. Therefore, in clear contrast with the empirical evidence based on Granger-causality tests, the main contribution of the paper comes from the analysis of the transmission of credit and liquidity risk by examining a broad network of relations between the two risks in nine EMU sovereign debt markets from 2008 to 2018, explicitly examining the net pairwise connectedness among all the possible pairs formed from the 18 sovereign risk indicators. The results of this analysis indicate that, on average, risk transmission goes mostly from credit to liquidity risk (both within and across countries). This finding is crucial for policymakers because it indicates that rising credit risk is the primary driver of yield spread increases, and actions to strengthen the budgetary position of euro-area economies are essential. Finally, our results indicate that sovereign risk transmission is time-varying. Although both liquidity and credit risk were transmitted across countries during the Global Financial Crisis, we mainly observed the transmission of liquidity risk across them during the European sovereign debt crisis, suggesting that investors prefer sovereign debt that is easier to trade when market liquidity dries up. |
| Keywords: | Liquidity; Credit risk; EMU sovereign bonds; MTS bond market; Dynamic connectedness; Time-varying parameters. JEL classification: C22, C53, G12, G14, G15. |
| Date: | 2025–01 |
| URL: | https://d.repec.org/n?u=RePEc:ira:wpaper:202504 |