Violence is commonly linked with large urban areas, and as a social phenomenon, it is presumed to scale super-linearly with population size. This study explores the hypothesis that smaller, isolated cities in Africa may experience a heightened intensity of violence against civilians. It aims to investigate the correlation between the risk of experiencing violence with a city's size and its geographical isolation. Over a 20-year period, the incidence of civilian casualties has been analysed to assess lethality in relation to varying degrees of isolation and city sizes. African cities are categorised by isolation (number of highway connections) and centrality (the estimated frequency of journeys). Findings suggest that violence against civilians exhibits a sub-linear pattern, with larger cities witnessing fewer casualties per 100,000 inhabitants. Remarkably, individuals in isolated cities face a quadrupled risk of a casualty compared to those in more connected cities.
{"title":"Geographical Isolation as a Driver of Political Violence in African Cities","authors":"Rafael Prieto-Curiel, Ronaldo Menezes","doi":"arxiv-2408.03755","DOIUrl":"https://doi.org/arxiv-2408.03755","url":null,"abstract":"Violence is commonly linked with large urban areas, and as a social\u0000phenomenon, it is presumed to scale super-linearly with population size. This\u0000study explores the hypothesis that smaller, isolated cities in Africa may\u0000experience a heightened intensity of violence against civilians. It aims to\u0000investigate the correlation between the risk of experiencing violence with a\u0000city's size and its geographical isolation. Over a 20-year period, the\u0000incidence of civilian casualties has been analysed to assess lethality in\u0000relation to varying degrees of isolation and city sizes. African cities are\u0000categorised by isolation (number of highway connections) and centrality (the\u0000estimated frequency of journeys). Findings suggest that violence against\u0000civilians exhibits a sub-linear pattern, with larger cities witnessing fewer\u0000casualties per 100,000 inhabitants. Remarkably, individuals in isolated cities\u0000face a quadrupled risk of a casualty compared to those in more connected\u0000cities.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matteo Bruno, Hygor Piaget Monteiro Melo, Bruno Campanelli, Vittorio Loreto
Proximity-based cities have attracted much attention in recent years. The 15-minute city, in particular, heralded a new vision for cities where essential services must be easily accessible. Despite its undoubted merit in stimulating discussion on new organisations of cities, the 15-minute city cannot be applicable everywhere, and its very definition raises a few concerns. Here, we tackle the feasibility and practicability of the '15-minute city' model in many cities worldwide. We provide a worldwide quantification of how close cities are to the ideal of the 15-minute city. To this end, we measure the accessibility times to resources and services, and we reveal strong heterogeneity of accessibility within and across cities, with a significant role played by local population densities. We provide an online platform (href{whatif.sonycsl.it/15mincity}{whatif.sonycsl.it/15mincity}) to access and visualise accessibility scores for virtually all cities worldwide. The heterogeneity of accessibility within cities is one of the sources of inequality. We thus simulate how much a better redistribution of resources and services could heal inequity by keeping the same resources and services or by allowing for virtually infinite resources. We highlight pronounced discrepancies among cities in the minimum number of additional services needed to comply with the 15-minute city concept. We conclude that the proximity-based paradigm must be generalised to work on a wide range of local population densities. Finally, socio-economic and cultural factors should be included to shift from time-based to value-based cities.
{"title":"A universal framework for inclusive 15-minute cities","authors":"Matteo Bruno, Hygor Piaget Monteiro Melo, Bruno Campanelli, Vittorio Loreto","doi":"arxiv-2408.03794","DOIUrl":"https://doi.org/arxiv-2408.03794","url":null,"abstract":"Proximity-based cities have attracted much attention in recent years. The\u000015-minute city, in particular, heralded a new vision for cities where essential\u0000services must be easily accessible. Despite its undoubted merit in stimulating\u0000discussion on new organisations of cities, the 15-minute city cannot be\u0000applicable everywhere, and its very definition raises a few concerns. Here, we\u0000tackle the feasibility and practicability of the '15-minute city' model in many\u0000cities worldwide. We provide a worldwide quantification of how close cities are\u0000to the ideal of the 15-minute city. To this end, we measure the accessibility\u0000times to resources and services, and we reveal strong heterogeneity of\u0000accessibility within and across cities, with a significant role played by local\u0000population densities. We provide an online platform\u0000(href{whatif.sonycsl.it/15mincity}{whatif.sonycsl.it/15mincity}) to access and\u0000visualise accessibility scores for virtually all cities worldwide. The\u0000heterogeneity of accessibility within cities is one of the sources of\u0000inequality. We thus simulate how much a better redistribution of resources and\u0000services could heal inequity by keeping the same resources and services or by\u0000allowing for virtually infinite resources. We highlight pronounced\u0000discrepancies among cities in the minimum number of additional services needed\u0000to comply with the 15-minute city concept. We conclude that the proximity-based\u0000paradigm must be generalised to work on a wide range of local population\u0000densities. Finally, socio-economic and cultural factors should be included to\u0000shift from time-based to value-based cities.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite substantial investments in infectious disease research over the past decades, the field continues to struggle with inadequate long-term investment strategies and resource disparities, which highlights the critical need for a better understanding of funding and research landscapes to support evidence-based policymaking. Our study presents a novel perspective on the interconnectedness of evolving infectious disease knowledge. Through identifying publications based on funded and unfunded research, the analysis of temporal network of infectious disease associations reveals (i) growing compartmentalisation of funded research, i.e., it focuses on the groups of infectious diseases with readily established connections, and (ii) the growth in global integration in unfunded research, i.e., it tends to be more widely exploratory and links distant diseases. Moreover, we find that in both funded and unfunded research prominent diseases like HIV, malaria and tuberculosis have strong bridging effects facilitating global integration, while diphtheria, tetanus, and pertussis are characterised with strong local connectivity between themselves. We also find that although coronavirus has seen a surge in publications since COVID-19, its systemic impact on the interconnectedness of infectious disease knowledge remains relatively low. Our work highlights the importance of considering the interconnectedness of infectious diseases in health policy making and has potential to contribute to more efficient health resource allocation.
{"title":"Measuring interconnectedness of infectious diseases in funded and unfunded research: a temporal network analysis on bibliometric data 1995-2022","authors":"Anbang Du, Michael Head, Markus Brede","doi":"arxiv-2408.03140","DOIUrl":"https://doi.org/arxiv-2408.03140","url":null,"abstract":"Despite substantial investments in infectious disease research over the past\u0000decades, the field continues to struggle with inadequate long-term investment\u0000strategies and resource disparities, which highlights the critical need for a\u0000better understanding of funding and research landscapes to support\u0000evidence-based policymaking. Our study presents a novel perspective on the\u0000interconnectedness of evolving infectious disease knowledge. Through\u0000identifying publications based on funded and unfunded research, the analysis of\u0000temporal network of infectious disease associations reveals (i) growing\u0000compartmentalisation of funded research, i.e., it focuses on the groups of\u0000infectious diseases with readily established connections, and (ii) the growth\u0000in global integration in unfunded research, i.e., it tends to be more widely\u0000exploratory and links distant diseases. Moreover, we find that in both funded\u0000and unfunded research prominent diseases like HIV, malaria and tuberculosis\u0000have strong bridging effects facilitating global integration, while diphtheria,\u0000tetanus, and pertussis are characterised with strong local connectivity between\u0000themselves. We also find that although coronavirus has seen a surge in\u0000publications since COVID-19, its systemic impact on the interconnectedness of\u0000infectious disease knowledge remains relatively low. Our work highlights the\u0000importance of considering the interconnectedness of infectious diseases in\u0000health policy making and has potential to contribute to more efficient health\u0000resource allocation.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Food security is a critical issue closely linked to human being. With the increasing demand for food, international trade has become the main access to supplementing domestic food shortages, which not only alleviates local food shocks, but also exposes economies to global food crises. In this paper, we construct four temporal international crop trade networks (iCTNs) based on trade values of maize, rice, soybean and wheat, and describe the structural evolution of different iCTNs from{ {1993}} to 2018. We find that the size of all the four iCTNs expanded from{ {1993}} to 2018 with more participants and larger trade values. Our results show that the iCTNs not only become tighter according to the increasing in network density and clustering coefficient, but also get more similar. We also find that the iCTNs are not always disassortative, unlike the world cereal trade networks and other international commodity trade networks. The degree assortative coefficients depend on degree directions and crop types. The analysis about assortativity also indicates that economies with high out-degrees tend to connect with economies with low in-degrees and low out-degrees. Additionally, we compare the structure of the four iCTNs to enhance our understanding of the international food trade system. Although the overall evolutionary patterns of different iCTNs are similar, some crops exhibit idiosyncratic trade patterns. It highlights the need to consider different crop networks' idiosyncratic features while making food policies. Our findings about the dynamics of the iCTNs play an important role in understanding vulnerabilities in the global food system.
{"title":"Structural evolution of international crop trade networks","authors":"Yin-Ting Zhang, Wei-Xing Zhou","doi":"arxiv-2408.02986","DOIUrl":"https://doi.org/arxiv-2408.02986","url":null,"abstract":"Food security is a critical issue closely linked to human being. With the\u0000increasing demand for food, international trade has become the main access to\u0000supplementing domestic food shortages, which not only alleviates local food\u0000shocks, but also exposes economies to global food crises. In this paper, we\u0000construct four temporal international crop trade networks (iCTNs) based on\u0000trade values of maize, rice, soybean and wheat, and describe the structural\u0000evolution of different iCTNs from{ {1993}} to 2018. We find that the size of\u0000all the four iCTNs expanded from{ {1993}} to 2018 with more participants and\u0000larger trade values. Our results show that the iCTNs not only become tighter\u0000according to the increasing in network density and clustering coefficient, but\u0000also get more similar. We also find that the iCTNs are not always\u0000disassortative, unlike the world cereal trade networks and other international\u0000commodity trade networks. The degree assortative coefficients depend on degree\u0000directions and crop types. The analysis about assortativity also indicates that\u0000economies with high out-degrees tend to connect with economies with low\u0000in-degrees and low out-degrees. Additionally, we compare the structure of the\u0000four iCTNs to enhance our understanding of the international food trade system.\u0000Although the overall evolutionary patterns of different iCTNs are similar, some\u0000crops exhibit idiosyncratic trade patterns. It highlights the need to consider\u0000different crop networks' idiosyncratic features while making food policies. Our\u0000findings about the dynamics of the iCTNs play an important role in\u0000understanding vulnerabilities in the global food system.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Transit is a crucial mode of transportation, especially in urban areas and for urban and rural disadvantaged communities. Because extreme temperatures often pose threats to the elderly, members of the disability community, and other vulnerable populations, this study seeks to understand the level of influence that extreme temperatures may have on transit users across different demographic groups. In this case study for Atlanta, GA, heat stress is predicted for 2019 transit riders (using transit rider activity survey data) and for three future climate scenarios, SSP245, SSP370, and SSP585, into the year 2100. The HeatPath Analyzer and TransitSim 4.0 models were applied to predict cumulative heat exposure and trip-level risk for 35,999 trip equivalents for an average Atlanta area weekday in the summer of 2019. The analyses show that under 2019 weather conditions, 8.33% of summer trips were estimated to be conducted under extreme heat. With the projected future climate conditions, the percentage of trips under extreme heat risk grows steadily. By 2100, 37.1%, 56.1%, and 76.4% are projected to be under extreme heat risk for scenarios SSP245, SSP370, and SSP585, respectively. Under current weather conditions, Atlanta transit riders that own no vehicles and transit riders that are African American are disproportionately influenced by extreme heat. The disparity between these two groups and other groups of transit riders becomes wider as climate change continues to exacerbate. The findings of the study highlight an urgent need to implement heat mitigation and adaptation strategies in urban transit networks.
{"title":"Transit Rider Heat Stress in Atlanta, GA under Current and Future Climate Scenarios","authors":"Huiying Fan, Geyu Lyu, Hongyu Lu, Angshuman Guin, Randall Guensler","doi":"arxiv-2408.03457","DOIUrl":"https://doi.org/arxiv-2408.03457","url":null,"abstract":"Transit is a crucial mode of transportation, especially in urban areas and\u0000for urban and rural disadvantaged communities. Because extreme temperatures\u0000often pose threats to the elderly, members of the disability community, and\u0000other vulnerable populations, this study seeks to understand the level of\u0000influence that extreme temperatures may have on transit users across different\u0000demographic groups. In this case study for Atlanta, GA, heat stress is\u0000predicted for 2019 transit riders (using transit rider activity survey data)\u0000and for three future climate scenarios, SSP245, SSP370, and SSP585, into the\u0000year 2100. The HeatPath Analyzer and TransitSim 4.0 models were applied to\u0000predict cumulative heat exposure and trip-level risk for 35,999 trip\u0000equivalents for an average Atlanta area weekday in the summer of 2019. The\u0000analyses show that under 2019 weather conditions, 8.33% of summer trips were\u0000estimated to be conducted under extreme heat. With the projected future climate\u0000conditions, the percentage of trips under extreme heat risk grows steadily. By\u00002100, 37.1%, 56.1%, and 76.4% are projected to be under extreme heat risk for\u0000scenarios SSP245, SSP370, and SSP585, respectively. Under current weather\u0000conditions, Atlanta transit riders that own no vehicles and transit riders that\u0000are African American are disproportionately influenced by extreme heat. The\u0000disparity between these two groups and other groups of transit riders becomes\u0000wider as climate change continues to exacerbate. The findings of the study\u0000highlight an urgent need to implement heat mitigation and adaptation strategies\u0000in urban transit networks.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Identifying influential spreaders is a crucial problem for practical applications in network science. The core-periphery(C-P) structure, common in many real-world networks, comprises a densely interconnected group of nodes(core) and the rest of the sparsely connected nodes subordinated to the core(periphery). Core nodes are expected to be more influential than periphery nodes generally, but recent studies suggest that this is not the case in some networks. In this work, we look for mesostructural conditions that arise when core nodes are significantly more influential than periphery nodes. In particular, we investigate the roles of the internal and external connectivity of cores in their relative influence. We observe that the internal and external connectivity of cores are broadly distributed, and the relative influence of the cores is also broadly distributed in real-world networks. Our key finding is that the internal connectivity of cores is positively correlated with their relative influence, whereas the relative influence increases up to a certain value of the external connectivity and decreases thereafter. Finally, results from the model-generated networks clarify the observations from the real-world networks. Our findings provide a structural condition for influential cores in networks and shed light on why some cores are influential and others are not.
{"title":"Identifying influential node groups in networks with core-periphery structure","authors":"Gyuho Bae, Philip A. Knight, Young-Ho Eom","doi":"arxiv-2408.02370","DOIUrl":"https://doi.org/arxiv-2408.02370","url":null,"abstract":"Identifying influential spreaders is a crucial problem for practical\u0000applications in network science. The core-periphery(C-P) structure, common in\u0000many real-world networks, comprises a densely interconnected group of\u0000nodes(core) and the rest of the sparsely connected nodes subordinated to the\u0000core(periphery). Core nodes are expected to be more influential than periphery\u0000nodes generally, but recent studies suggest that this is not the case in some\u0000networks. In this work, we look for mesostructural conditions that arise when\u0000core nodes are significantly more influential than periphery nodes. In\u0000particular, we investigate the roles of the internal and external connectivity\u0000of cores in their relative influence. We observe that the internal and external\u0000connectivity of cores are broadly distributed, and the relative influence of\u0000the cores is also broadly distributed in real-world networks. Our key finding\u0000is that the internal connectivity of cores is positively correlated with their\u0000relative influence, whereas the relative influence increases up to a certain\u0000value of the external connectivity and decreases thereafter. Finally, results\u0000from the model-generated networks clarify the observations from the real-world\u0000networks. Our findings provide a structural condition for influential cores in\u0000networks and shed light on why some cores are influential and others are not.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingrong She, Jan Bachmann, Fariba Karimi, Leto Peel
We examine gender differences in collaboration networks and academic career progression in physics. We use the likelihood and time to become a principal investigator (PI) and the length of an author's career to measure career progression. Utilising logistic regression and accelerated failure time models, we examine whether the effect of collaboration behaviour varies by gender. We find that, controlling for the number of publications, the relationship between collaborative behaviour and career progression is almost the same for men and women. Specifically, we find that those who eventually reach principal investigator (PI) status, tend to have published with more unique collaborators. In contrast, publishing repeatedly with the same highly interconnected collaborators and/or larger number of coauthors per publication is characteristic of shorter career lengths and those that do not attain PI status. We observe that the tie strength is stronger for women than men, and women tend to collaborate in more tightly connected and larger groups than men. Finally, we observe that women are less likely to attain the status of PI throughout their careers and have a lower survival probability compared to men, which calls for policies to close this crucial gap.
我们研究了物理学合作网络和学术职业发展中的性别差异。我们使用成为首席研究员（PI）的可能性和时间以及作者的职业生涯长度来衡量职业发展。利用逻辑回归和加速失败时间模型，我们研究了合作行为的影响是否因性别而异。我们发现，在控制发表论文数量的情况下，男性和女性的合作行为与职业发展之间的关系几乎相同。具体来说，我们发现那些最终达到首席研究员（PI）地位的人往往与更多独特的合作者一起发表过论文。与此相反，那些职业生涯较短和没有获得首席研究员地位的人，其特点是反复与相同的、联系紧密的合作者发表论文，并且/或者每篇论文的共同作者人数较多。最后，我们发现女性在整个职业生涯中获得 PI 地位的可能性较低，与男性相比，女性的生存概率也较低，这就需要制定政策来缩小这一关键差距。
{"title":"Gender differences in collaboration and career progression in physics","authors":"Mingrong She, Jan Bachmann, Fariba Karimi, Leto Peel","doi":"arxiv-2408.02482","DOIUrl":"https://doi.org/arxiv-2408.02482","url":null,"abstract":"We examine gender differences in collaboration networks and academic career\u0000progression in physics. We use the likelihood and time to become a principal\u0000investigator (PI) and the length of an author's career to measure career\u0000progression. Utilising logistic regression and accelerated failure time models,\u0000we examine whether the effect of collaboration behaviour varies by gender. We\u0000find that, controlling for the number of publications, the relationship between\u0000collaborative behaviour and career progression is almost the same for men and\u0000women. Specifically, we find that those who eventually reach principal\u0000investigator (PI) status, tend to have published with more unique\u0000collaborators. In contrast, publishing repeatedly with the same highly\u0000interconnected collaborators and/or larger number of coauthors per publication\u0000is characteristic of shorter career lengths and those that do not attain PI\u0000status. We observe that the tie strength is stronger for women than men, and\u0000women tend to collaborate in more tightly connected and larger groups than men.\u0000Finally, we observe that women are less likely to attain the status of PI\u0000throughout their careers and have a lower survival probability compared to men,\u0000which calls for policies to close this crucial gap.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Massimiliano Fessina, Giulio Cimini, Tiziano Squartini, Pablo Astudillo-Estévez, Stefan Thurner, Diego Garlaschelli
Production networks constitute the backbone of every economic system. They are inherently fragile as several recent crises clearly highlighted. Estimating the system-wide consequences of local disruptions (systemic risk) requires detailed information on the supply chain networks (SCN) at the firm-level, as systemic risk is associated with specific mesoscopic patterns. However, such information is usually not available and realistic estimates must be inferred from available sector-level data such as input-output tables and firm-level aggregate output data. Here we explore the ability of several maximum-entropy algorithms to infer realizations of SCNs characterized by a realistic level of systemic risk. We are in the unique position to test them against the actual Ecuadorian production network at the firm-level. Concretely, we compare various properties, including the Economic Systemic Risk Index, of the Ecuadorian production network with those from four inference models. We find that the most realistic systemic risk content at the firm-level is retrieved by the model that incorporates information about firm-specific input disaggregated by sector, indicating the importance of correctly accounting for firms' heterogeneous input profiles across sectors. Our results clearly demonstrate the minimal amount of empirical information at the sector level that is necessary to statistically generate synthetic SCNs that encode realistic firm-specific systemic risk.
{"title":"Inferring firm-level supply chain networks with realistic systemic risk from industry sector-level data","authors":"Massimiliano Fessina, Giulio Cimini, Tiziano Squartini, Pablo Astudillo-Estévez, Stefan Thurner, Diego Garlaschelli","doi":"arxiv-2408.02467","DOIUrl":"https://doi.org/arxiv-2408.02467","url":null,"abstract":"Production networks constitute the backbone of every economic system. They\u0000are inherently fragile as several recent crises clearly highlighted. Estimating\u0000the system-wide consequences of local disruptions (systemic risk) requires\u0000detailed information on the supply chain networks (SCN) at the firm-level, as\u0000systemic risk is associated with specific mesoscopic patterns. However, such\u0000information is usually not available and realistic estimates must be inferred\u0000from available sector-level data such as input-output tables and firm-level\u0000aggregate output data. Here we explore the ability of several maximum-entropy\u0000algorithms to infer realizations of SCNs characterized by a realistic level of\u0000systemic risk. We are in the unique position to test them against the actual\u0000Ecuadorian production network at the firm-level. Concretely, we compare various\u0000properties, including the Economic Systemic Risk Index, of the Ecuadorian\u0000production network with those from four inference models. We find that the most\u0000realistic systemic risk content at the firm-level is retrieved by the model\u0000that incorporates information about firm-specific input disaggregated by\u0000sector, indicating the importance of correctly accounting for firms'\u0000heterogeneous input profiles across sectors. Our results clearly demonstrate\u0000the minimal amount of empirical information at the sector level that is\u0000necessary to statistically generate synthetic SCNs that encode realistic\u0000firm-specific systemic risk.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the evolution of cooperation in multiplayer games is of vital significance for natural and social systems. An important challenge is that group interactions often leads to nonlinear synergistic effects. However, previous models mainly focus on deterministic nonlinearity where the arise of synergy or discounting effect is determined by certain conditions, ignoring uncertainty and stochasticity in real-world systems. Here, we develop a probabilistic framework to study the cooperative behavior in stochastic nonlinear public goods games. Through both analytical treatment and Monte Carlo simulations, we provide comprehensive understanding of social dilemmas with stochastic nonlinearity in both well-mixed and structured populations. We find that increasing the degree of nonlinearity makes synergy more advantageous when competing with discounting, thereby promoting cooperation. Interestingly, we show that network reciprocity loses effectiveness when the probability of synergy is small. Moreover, group size exhibits nonlinear effects on group cooperation regardless of the underlying structure. Our findings thus provide novel insights into how stochastic nonlinearity influences the emergence of prosocial behavior.
{"title":"Evolutionary dynamics in stochastic nonlinear public goods games","authors":"Wenqiang Zhu, Xin Wang, Chaoqian Wang, Longzhao Liu, Jiaxin Hu, Zhiming Zheng, Shaoting Tang, Hongwei Zheng, Jin Dong","doi":"arxiv-2408.02042","DOIUrl":"https://doi.org/arxiv-2408.02042","url":null,"abstract":"Understanding the evolution of cooperation in multiplayer games is of vital\u0000significance for natural and social systems. An important challenge is that\u0000group interactions often leads to nonlinear synergistic effects. However,\u0000previous models mainly focus on deterministic nonlinearity where the arise of\u0000synergy or discounting effect is determined by certain conditions, ignoring\u0000uncertainty and stochasticity in real-world systems. Here, we develop a\u0000probabilistic framework to study the cooperative behavior in stochastic\u0000nonlinear public goods games. Through both analytical treatment and Monte Carlo\u0000simulations, we provide comprehensive understanding of social dilemmas with\u0000stochastic nonlinearity in both well-mixed and structured populations. We find\u0000that increasing the degree of nonlinearity makes synergy more advantageous when\u0000competing with discounting, thereby promoting cooperation. Interestingly, we\u0000show that network reciprocity loses effectiveness when the probability of\u0000synergy is small. Moreover, group size exhibits nonlinear effects on group\u0000cooperation regardless of the underlying structure. Our findings thus provide\u0000novel insights into how stochastic nonlinearity influences the emergence of\u0000prosocial behavior.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper responds to a commentary by Neal (2024) regarding the Distinctiveness centrality metrics introduced by Fronzetti Colladon and Naldi (2020). Distinctiveness centrality offers a novel reinterpretation of degree centrality, particularly emphasizing the significance of direct connections to loosely connected peers within (social) networks. This response paper presents a more comprehensive analysis of the correlation between Distinctiveness and the Beta and Gamma measures. All five distinctiveness measures are considered, as well as a more meaningful range of the {alpha} parameter and different network topologies, distinguishing between weighted and unweighted networks. Findings indicate significant variability in correlations, supporting the viability of Distinctiveness as alternative or complementary metrics within social network analysis. Moreover, the paper presents computational complexity analysis and simplified R code for practical implementation. Encouraging initial findings suggest potential applications in diverse domains, inviting further exploration and comparative analyses.
{"title":"Why distinctiveness centrality is distinctive","authors":"A. Fronzetti Colladon, M. Naldi","doi":"arxiv-2408.02076","DOIUrl":"https://doi.org/arxiv-2408.02076","url":null,"abstract":"This paper responds to a commentary by Neal (2024) regarding the\u0000Distinctiveness centrality metrics introduced by Fronzetti Colladon and Naldi\u0000(2020). Distinctiveness centrality offers a novel reinterpretation of degree\u0000centrality, particularly emphasizing the significance of direct connections to\u0000loosely connected peers within (social) networks. This response paper presents\u0000a more comprehensive analysis of the correlation between Distinctiveness and\u0000the Beta and Gamma measures. All five distinctiveness measures are considered,\u0000as well as a more meaningful range of the {alpha} parameter and different\u0000network topologies, distinguishing between weighted and unweighted networks.\u0000Findings indicate significant variability in correlations, supporting the\u0000viability of Distinctiveness as alternative or complementary metrics within\u0000social network analysis. Moreover, the paper presents computational complexity\u0000analysis and simplified R code for practical implementation. Encouraging\u0000initial findings suggest potential applications in diverse domains, inviting\u0000further exploration and comparative analyses.","PeriodicalId":501043,"journal":{"name":"arXiv - PHYS - Physics and Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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