nep-net New Economics Papers
on Network Economics
Issue of 2021‒05‒10
fifteen papers chosen by
Alfonso Rosa García
Universidad de Murcia

  1. Inequality is rising where social network segregation interacts with urban topology By Gergõ Tóth; Johannes Wachs; Riccardo Di Clemente; Ákos Jakobi; Bence Ságvári; János Kertész; Balázs Lengyel
  2. Active peer effects in residential photovoltaic adoption: evidence on impact drivers among potential and current adopters in Germany By Fabian Scheller; S\"oren Graupner; James Edwards; Jann Weinand; Thomas Bruckner
  3. What 5,000 acknowledgements tell us about informal collaboration in financial economics By Rose, Michael E.; Georg, Co-Pierre
  4. Social Exclusion and Ethnic Segregation in Schools: The Role of Teacher's Ethnic Prejudice By Alan, Sule; Duysak, Enes; Kubilay, Elif; Mumcu, Ipek
  5. A model of inter-organizational network formation By Shweta Gaonkar; Angelo Mele
  6. Repeated collaboration of inventors across European regions By Gergõ Tóth; Zoltán Elekes; Sándor Juhász; Balázs Lengyel
  7. Trade networks and shock transmission within the Italian production system By Stefano Costa; Federico Sallusti; Claudio Vicarelli
  8. The Fetters of the Sib - An Experimental Study in Burkina Faso By Hadnes, Myriam; Kosfeld, Michael; Nilgen, Marco; Vollan, Björn
  9. Sooner Rather Than Later: Social Networks and Technology Adoption By Chowdhury, Shyamal; Satish, Varun; Sulaiman, Munshi; Sun, Yi
  10. Economic Complexity and Industrial Upgrading in the Product Space Network - Opportunities for the City of Laval, Canada By Yihan Wang; Ekaterina Turkina
  11. Does Mentoring Increase the Collaboration Networks of Female Economists? An Evaluation of the CeMENT Randomized Trial By Donna K. Ginther; Rina Na
  12. Selecting the Most Effective Nudge: Evidence from a Large-Scale Experiment on Immunization By Abhijit Banerjee; Arun G. Chandrasekhar; Suresh Dalpath; Esther Duflo; John Floretta; Matthew O. Jackson; Harini Kannan; Francine N. Loza; Anirudh Sankar; Anna Schrimpf; Maheshwor Shrestha
  13. Post-Brexit power of European Union from the world trade network analysis By Justin Loye; Katia Jaffr\`es-Runser; Dima Shepelyansky
  14. Industry interconnectedness and regional economic growth in Germany By Shutters, Shade T.; Seibert, Holger; Alm, Bastian; Waters, Keith
  15. Faith and Assimilation: Italian Immigrants in the US By Gagliarducci, Stefano; Tabellini, Marco

  1. By: Gergõ Tóth (Agglomeration and Social Networks Lendület Research Group, Centre for Economic-and Regional Studies, Budapest, Hungaryand Spatial Dynamics Lab, University College Dublin, Dublin, Ireland); Johannes Wachs (Institute for Data, Process and Knowledge Management, Vienna University of Economics and Business, Vienna, Austria and Complexity Science Hub Vienna, Vienna, Austria); Riccardo Di Clemente (Department of Computer Science, University of Exeter, Exeter, UK and Centre for Advanced Spatial Analysis, University College London, London, UK); Ákos Jakobi (Department of Regional Science, Eötvös Loránd University, Budapest, Hungary and Institute of Advanced Studies, Kõszeg, Hungary); Bence Ságvári (CSS-Recens, Centre for Social Sciences, Budapest, Hungary and International Business School Budapest, Budapest, Hungary); János Kertész (Department of Network and Data Science, Central European University, Budapest, Hungary); Balázs Lengyel (Agglomeration and Social Networks Lendület Research Group, Centre for Economic-and Regional Studies, Budapest, Hungary; International Business School Budapest, Budapest, Hungary and NETI Lab, Corvinus Institute for Advanced Studies, Budapest Corvinus University, Budapest, Hungary)
    Abstract: Social networks amplify inequalities by fundamental mechanisms of social tie formation such as homophily and triadic closure. These forces sharpen social segregation, which is reflected in fragmented social network structure. Geographical impediments such as distance and physical or administrative boundaries also reinforce social segregation. Yet, less is known about the joint relationships between social network structure, urban geography, and inequality. In this paper we analyze an online social network and find that the fragmentation of social networks is significantly higher in towns in which residential neighborhoods are divided by physical barriers such as rivers and railroads. Towns in which neighborhoods are relatively distant from the center of town and amenities are spatially concentrated are also more socially segregated. Using a two-stage model, we show that these urban geography features have significant relationships with income inequality via social network fragmentation. In other words, the geographic features of a place can compound economic inequalities via social networks.
    Keywords: social networks, income inequality, social segregation, network fragmentation, geographicalcal boundaries, urban topology
    JEL: C36 D85 I32 N34 R23 Z13
    Date: 2021–03
  2. By: Fabian Scheller; S\"oren Graupner; James Edwards; Jann Weinand; Thomas Bruckner
    Abstract: While the importance of peer influences has been demonstrated in several studies, little is known about the underlying mechanisms of active peer effects in residential photovoltaic (PV) diffusion. Empirical evidence indicates that the impacts of inter-subjective exchanges are dependent on the subjective mutual evaluation of the interlocutors. This paper aims to quantify, how subjective evaluations of peers affect peer effects across different stages of PV adoption decision-making. The findings of a survey among potential and current adopters in Germany(N=1,165)confirm two hypotheses. First, peer effects play a role in residential PV adoption: the number of peer adopters in the decision-maker's social circle has a positive effect on the decision-maker's belief that their social network supports PV adoption; their ascription of credibility on PV-related topics to their peers; and their interest in actively seeking information from their peers in all decision-making stages. Second, there is a correlation between the perceived positive attributes of a given peer and the reported influence of said peer within the decision-making process, suggesting that decision-makers' subjective evaluations of peers play an important role in active peer effects. Decision-makers are significantly more likely to engage in and be influenced by interactions with peers who they perceive as competent, trustworthy, and likeable. In contrast, attributes such as physical closeness and availability have a less significant effect. From a policymaking perspective, this study suggests that the density and quality of peer connections empower potential adopters. Accordingly, peer consultation and community-led outreach initiatives should be promoted to accelerate residential PV adoption.
    Date: 2021–05
  3. By: Rose, Michael E.; Georg, Co-Pierre
    Abstract: We present and discuss a novel dataset on informal collaboration in financial economics, manually collected from more than 5,000 acknowledgement sections of published papers. We find that informal collaboration is the norm in financial economics, while generational differences in informal collaboration exist and reciprocity among collaborators prevails. Female researchers appear less often in acknowledgements than comparable male researchers. Information derived from networks of informal collaboration allows us to predict academic impact of both researchers and papers even better than information from co-author networks. Finally, we study the characteristics of the networks using various measures from network theory and characterize what determines a researcher's position in it. The data presented here may help other researchers to shed light on an under-explored topic.
    Keywords: intellectual collaboration,acknowledgements,social networks,financial economics
    JEL: A14 D83 G00 O33
    Date: 2021
  4. By: Alan, Sule; Duysak, Enes; Kubilay, Elif; Mumcu, Ipek
    Abstract: Using detailed data on primary school children and their teachers, we show that teachers who hold prejudicial attitudes towards an ethnic group create socially and spatially segregated classrooms. We identify this relationship by leveraging a natural experiment where newly arrived refugee children are randomly assigned to teachers within schools. We elicit children's social networks to construct multiple measures of social exclusion and ethnic segregation in classrooms. We find that teachers' ethnic prejudice significantly lowers the prevalence of inter-ethnic social links, increases homophilic ties among host children, and puts refugee children at a higher risk of peer violence. Biased teachers' exclusionary classroom practices emerge as a likely mechanism that explains our results. We find that biased teachers tend to spatially segregate refugees, seat them at the back corners of classrooms, away from attention. Our results highlight the role of teachers in achieving integrated schools in a world of increasing ethnic diversity.
    Keywords: ethnic prejudice; ethnic segregation; social exclusion; Teacher effects
    JEL: I24 J15
    Date: 2021–02
  5. By: Shweta Gaonkar; Angelo Mele
    Abstract: How do inter-organizational networks emerge? Accounting for interdependence among ties while studying tie formation is one of the key challenges in this area of research. We address this challenge using an equilibrium framework where firms' decisions to form links with other firms are modeled as a strategic game. In this game, firms weigh the costs and benefits of establishing a relationship with other firms and form ties if their net payoffs are positive. We characterize the equilibrium networks as exponential random graphs (ERGM), and we estimate the firms' payoffs using a Bayesian approach. To demonstrate the usefulness of our approach, we apply the framework to a co-investment network of venture capital firms in the medical device industry. The equilibrium framework allows researchers to draw economic interpretation from parameter estimates of the ERGM Model. We learn that firms rely on their joint partners (transitivity) and prefer to form ties with firms similar to themselves (homophily). These results hold after controlling for the interdependence among ties. Another, critical advantage of a structural approach is that it allows us to simulate the effects of economic shocks or policy counterfactuals. We test two such policy shocks, namely, firm entry and regulatory change. We show how new firms' entry or a regulatory shock of minimum capital requirements increase the co-investment network's density and clustering.
    Date: 2021–05
  6. By: Gergõ Tóth (Agglomeration and Social Networks Lendület Research Group, Centre for Economic-and Regional Studies, Budapest, Hungary and Spatial Dynamics Lab, University College Dublin, Dublin, Ireland); Zoltán Elekes (Agglomeration and Social Networks Research Group, Centre for Economic and Regional Studiesand Centre for Regional Science at Umea University (CERUM), Umea University, 90187 Umea, Sweden); Sándor Juhász (NETI Lab, Corvinus Institute for Advanced Studies, Budapest Corvinus University, Budapest, Hungary); Balázs Lengyel (Agglomeration and Social Networks Lendület Research Group, Centre for Economic-and Regional Studies, Budapest, Hungary;International Business School Budapest, Budapest, Hungaryand NETI Lab, Corvinus Institute for Advanced Studies, Budapest Corvinus University, Budapest, Hungary)
    Abstract: This paper explores the spatial patterns and underlying determinants of repeated inventor collaboration across European NUTS 3 regions. It is found that only a small fraction of co-inventor linkages across regions are repeated, while community detection reveals that these collaborations are clustered in geographical space more intensively compared with collaboration in general. Additional results from gravity modelling indicate that links in the inter-regional co-patenting network emerge mainly through the triadic collaboration of regions, while geographical proximity becomes the most influential factor for repeating co-inventor ties. In addition to that, the combination of technological similarity and shared third partner regions offer a premium for the likelihood of repeating collaboration, but only when geographical proximity is present as an enabler.
    Keywords: collaborative knowledge production; inter-regional collaboration; co-inventor network; repeated collaboration; European Research Area; gravity model
    JEL: D85 O31 O43 O52 R11 R58
    Date: 2021–03
  7. By: Stefano Costa; Federico Sallusti; Claudio Vicarelli
    Abstract: Making use of domestic and international input-output tables and network analysis indicators, we analyze international and domestic trade relationships of Italian industries looking at their ability of transmission of shocks. To do this, we also propose a new taxonomy being able to distinguish sectors in terms of the extent to, and the speed at, which they spread domestic and foreign economic shocks into the Italian production system. Our results show a mismatch between sectors having a central position in terms of trade relationships with foreign countries and those having a central role for the propagation of shocks within the Italian economic system. Only a small group of sectors has both a high openness to international markets and a central position within the network of Italian production system. It follows that the domestic transmission capacity of stimuli from abroad is limited: this aspect strongly compromises the possibility of benefiting from positive shocks deriving from increases in foreign demand, even if it could represent, at least in part, a safeguard element in the event of negative impulses deriving from the trend of the international economic cycle.
    Keywords: Input/output tables; network analysis; shocks transmission.
    Date: 2021–04–30
  8. By: Hadnes, Myriam; Kosfeld, Michael; Nilgen, Marco; Vollan, Björn
    Abstract: We conducted a field experiment in Burkina Faso to investigate the impact of sharing obligations within kin networks on entrepreneurial effort. The overall treatment effect we find is insignificant and goes in the opposite direction than previous literature suggests. Ex-post explorative analysis reveals that entrepreneurs in the two experimental groups reacted differently in their production process, with some entrepreneurs in the treatment group being able to utilize their kin network to their joint advantage.
    Keywords: Burkina Faso; Business Development; field experiment; Redristributive pressure; Sharing norms; Social norms
    JEL: C93 D13 H24 H26 O12
    Date: 2021–03
  9. By: Chowdhury, Shyamal (University of Sydney); Satish, Varun (University of Chicago); Sulaiman, Munshi (BRAC Institute of Governance and Development); Sun, Yi (University of Sydney)
    Abstract: Using data from a randomised experiment in Kenya, we estimate the causal effect of social networks on technology adoption. In this experiment, farmers were invited to information sessions about the use of Tissue Culture Banana (TCB), an in vitro banana cultivation technology. We find that an additional social connection with a treated farmer causes an untreated farmer to be 2.25 pp more likely to adopt TCB 6-18 months post-intervention, but not in the longer term. We provide evidence that the adoption of TCB by those social connections is the mechanism driving the effect; therefore, treated connections are significant because treated farmers are more likely to adopt. We also find that indirect social network effects, proxied for by eigenvector centrality, influence adoption at both the village level and the farmer level.
    Keywords: networks, social connections, agricultural technology adoption, Kenya
    JEL: O12 P36 Z13
    Date: 2021–04
  10. By: Yihan Wang (HEC Montréal - HEC Montréal, Métis Lab EM Normandie - EM Normandie - École de Management de Normandie); Ekaterina Turkina (HEC Montréal - HEC Montréal)
    Abstract: This paper studies a city-region's multi-level competitiveness based on the configurations of local product space network and agglomeration of Revealed Competitive Advantage (RCA) sectors. We undertake a mandate studying the economic complexity of the City of Laval and explore the opportunities of industrial upgrading in its product space network. Addressing the importance of subnational analysis of economic complexity, we find the divergence of a city-region's RCA sectors at regional, national and global levels. We also imply the contribution of the structural holes of a cityregion's product space network across RCA sectors as potential fields to attract FDI inflow and enhance economic growth. Then, we discover the correlated spatial agglomeration of RCA and structural hole sectors within a city-region's hierarchical ecosystem. Finally, we conclude the practical implications for policy makers and discusses future research directions.
    Date: 2020–11–24
  11. By: Donna K. Ginther; Rina Na
    Abstract: Previous research has shown that women in the treatment group of the CeMENT randomized controlled trial increased their publications and the likelihood that they were tenured in top 50 economics departments. This paper examines one potential mechanism, namely, that CeMENT expanded the collaboration networks of the participants. Our analysis finds that women who received the mentoring treatment had three additional pre-tenure coauthors, 1.6 more pre-tenure publications and 43 additional citations to those publications. After controlling for additional coauthors, the CeMENT program increased publications, and top-tier publications. These results suggest that the information conveyed at the workshop facilitated participants’ career success.
    JEL: A11 J16 J4
    Date: 2021–04
  12. By: Abhijit Banerjee; Arun G. Chandrasekhar; Suresh Dalpath; Esther Duflo; John Floretta; Matthew O. Jackson; Harini Kannan; Francine N. Loza; Anirudh Sankar; Anna Schrimpf; Maheshwor Shrestha
    Abstract: We evaluate a large-scale set of interventions to increase demand for immunization in Haryana, India. The policies under consideration include the two most frequently discussed tools—reminders and incentives—as well as an intervention inspired by the networks literature. We cross-randomize whether (a) individuals receive SMS reminders about upcoming vaccination drives; (b) individuals receive incentives for vaccinating their children; (c) influential individuals (information hubs, trusted individuals, or both) are asked to act as “ambassadors” receiving regular reminders to spread the word about immunization in their community. By taking into account different versions (or “dosages”) of each intervention, we obtain 75 unique policy combinations. We develop a new statistical technique—a smart pooling and pruning procedure—for finding a best policy from a large set, which also determines which policies are effective and the effect of the best policy. We proceed in two steps. First, we use a LASSO technique to collapse the data: we pool dosages of the same treatment if the data cannot reject that they had the same impact, and prune policies deemed ineffective. Second, using the remaining (pooled) policies, we estimate the effect of the best policy, accounting for the winner’s curse. The key outcomes are (i) the number of measles immunizations and (ii) the number of immunizations per dollar spent. The policy that has the largest impact (information hubs, SMS reminders, incentives that increase with each immunization) increases the number of immunizations by 44 % relative to the status quo. The most cost-effective policy (information hubs, SMS reminders, no incentives) increases the number of immunizations per dollar by 9.1%.
    JEL: C18 C93 D83 I15 O12 O15
    Date: 2021–04
  13. By: Justin Loye; Katia Jaffr\`es-Runser; Dima Shepelyansky
    Abstract: We develop the Google matrix analysis of the multiproduct world trade network obtained from the UN COMTRADE database in recent years. The comparison is done between this new approach and the usual Import-Export description of this world trade network. The Google matrix analysis takes into account the multiplicity of trade transactions thus highlighting in a better way the world influence of specific countries and products. It shows that after Brexit, the European Union of 27 countries has the leading position in the world trade network ranking, being ahead of USA and China. Our approach determines also a sensitivity of trade country balance to specific products showing the dominant role of machinery and mineral fuels in multiproduct exchanges. It also underlines the growing influence of Asian countries.
    Date: 2021–05
  14. By: Shutters, Shade T.; Seibert, Holger (Institut für Arbeitsmarkt- und Berufsforschung (IAB), Nürnberg [Institute for Employment Research, Nuremberg, Germany]); Alm, Bastian; Waters, Keith
    Abstract: "Urban systems, and regions more generally, are the epicenters of many of today's social issues. Yet they are also the global drivers of technological innovation and thus it is critical that we understand their vulnerabilities and what makes them resilient to different types of shocks. We take regions to be systems composed of internal networks of interdependent components. As the connectedness of those networks increases, it allows information and resources to move more rapidly within a region. Yet, it also increases the speed and efficiency at which the effects of shocks cascade through the system. Here we analyze regional networks of interdependent industries and how their structures relate to a region's vulnerability to shocks. Methodologically, we utilize a metric of economic connectedness, known as tightness, which attempts to quantify the ambiguous notion of a region's internal connectedness relative to other regions. Using industry employment, we calculate the economic tightness of German regions during the Great Recession, comparing it to each region's economic performance during the shock (2007-2009) and during recovery (2009-2011). We find that tightness is negatively correlated with changes in economic performance during the shock but positively correlated with performance during recovery. This suggests that regional economic planners face a tradeoff between being more productive or being more vulnerable to the next economic shock. Finally, we speculate on how these findings from the Great Recession may highlight potential implications of the ongoing COVID-19 pandemic and suggest future research that would compare outcomes of these two global shocks." (Author's abstract, IAB-Doku) ((en))
    JEL: J40 R00 R11 R12 R58
    Date: 2021–04–27
  15. By: Gagliarducci, Stefano; Tabellini, Marco
    Abstract: We study the effects of religious organizations on immigrants' assimilation. We focus on the arrival of Italian Catholic churches in the US between 1900 and 1920, when four million Italians had moved to America, and anti-Catholic sentiments were widespread. We combine newly collected Catholic directories on the presence of Italian churches across years and counties with the full count US Census of Population. We find that Italian churches reduced the social assimilation of Italian immigrants, lowering intermarriage rates and increasing ethnic residential segregation. We find no evidence that this was the result of either lower effort exerted by immigrants to ``fit in'' the American society or increased desire to vertically transmit national culture. Instead, we provide evidence for other two, non-mutually exclusive, mechanisms. First, Italian churches raised the frequency of interactions among fellow Italians, likely generating peer effects and reducing contact with other groups. Second, they increased the salience of the immigrant community among natives, thereby triggering backlash and discrimination.
    Keywords: Assimilation; Immigration; religious organizations
    JEL: J15 N31 Z12
    Date: 2021–02

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