Sándor Juhász | publications

2025

PNAS

Urban highways are barriers to social ties

Aiello, L. M., Vybornova, A., Juhász, S., Szell, M., and Bokányi, E.

Proceedings of the National Academy of Sciences, 2025

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Urban highways are common, especially in the US, making cities more car-centric. They promise the annihilation of distance but obstruct pedestrian mobility, thus playing a key role in limiting social interactions locally. Although this limiting role is widely acknowledged in urban studies, the quantitative relationship between urban highways and social ties is barely tested. Here we define a Barrier Score that relates massive, geolocated online social network data to highways in the 50 largest US cities. At the unprecedented granularity of individual social ties, we show that urban highways are associated with decreased social connectivity. This barrier effect is especially strong for short distances and consistent with historical cases of highways that were built to purposefully disrupt or isolate Black neighborhoods. By combining spatial infrastructure with social tie data, our method adds a new dimension to demographic studies of social segregation. Our study can inform reparative planning for an evidence-based reduction of spatial inequality, and more generally, support a better integration of the social fabric in urban planning.

2024

NS

Business transactions and ownership ties between firms

Lőrincz, L., Juhász, S., and O. Szabó, R.

Network Science, 2024

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In this study, we investigate the creation and persistence of interfirm ties in a large-scale business transaction network. Business transaction relations (firms buying or selling products or services to each other) are driven by economic motives, but because trust is essential to business relationships, the social connections of owners or the geographical proximity of firms can also influence their development. However, studying the formation of interfirm business transaction ties on a large scale is rare, because of the significant data demand. The business transaction and the ownership networks of Hungarian firms are constructed from two administrative datasets for 2016 and 2017. We show that direct or indirect connections in this two-layered network, including open triads in the business network, contribute to both the creation and persistence of business transaction ties. For our estimations, we utilize log-linear models and emphasize their efficiency in predicting links in such large networks. We contribute to the literature by presenting different patterns of business connections in a nationwide multilayer interfirm network.

2023

EPJ

Amenity complexity and urban locations of socio-economic mixing

Juhász, S., Pintér, G., Kovács, Á., Borza, E., Mónus, G., Lőrincz, L., and Lengyel, B.

EPJ Data Science, 2023

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Cities host diverse people and their mixing is the engine of prosperity. In turn, segregation and inequalities are common features of most cities and locations that enable the meeting of people with different socio-economic status are key for urban inclusion. In this study, we adopt the concept of economic complexity to quantify the sophistication of amenity supply at urban locations. We propose that neighborhood complexity and amenity complexity are connected to the ability of locations to attract diverse visitors from various socio-economic backgrounds across the city. We construct the measures of amenity complexity based on the local portfolio of diverse and non-ubiquitous amenities in Budapest, Hungary. Socio-economic mixing at visited third places is investigated by tracing the daily mobility of individuals and by characterizing their status by the real-estate price of their home locations. Results suggest that measures of ubiquity and diversity of amenities do not, but neighborhood complexity and amenity complexity are correlated with the urban centrality of locations. Urban centrality is a strong predictor of socio-economic mixing, but both neighborhood complexity and amenity complexity add further explanatory power to our models. Our work combines urban mobility data with economic complexity thinking to show that the diversity of non-ubiquitous amenities, central locations, and the potentials for socio-economic mixing are interrelated.

2022

EPB

Income-related spatial concentration of individual social capital in cities

Kovács, Á., Juhász, S., Bokányi, E., and Lengyel, B.

Environment and Planning B: Urban Analytics and City Science, 2022

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Social connections that span across diverse urban neighborhoods can support prosperity by mobilizing social capital. However, there is limited evidence on the spatial structure of individual social capital inside cities. This paper demonstrates that social capital measured by online social connections is spatially more concentrated for residents of lower-income neighborhoods than for residents of higher-income neighborhoods. We map the micro-geography of individual online social networks in the 50 largest metropolitan areas of the United States using a large-scale geolocalized Twitter dataset. We analyze the spatial dimension of individual social capital by the share of friends, closed triangles, and share of supported ties within circles of short distance radii (1, 3, 5, and 10 km) around users’ home location. We compare residents from below-median income neighborhoods with above-median income neighborhoods, and find that users living in relatively poorer neighborhoods have a significantly higher share of connections in close proximity. Moreover, their network is more cohesive and supported within a short distance from their home. These patterns prevail across the 50 largest US metropolitan areas with only a few exceptions. The found disparities in the micro-geographic concentration of social capital can feed segregation and income inequality within cities constraining social circles of low-income residents.

2021

SR

Universal patterns of long‐distance commuting and social assortativity in cities

Bokányi, E., Juhász, S., Karsai, M., and Lengyel, B.

Scientific Reports, 2021

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Millions commute to work every day in cities and interact with colleagues, partners, friends, and strangers. Commuting facilitates the mixing of people from distant and diverse neighborhoods, but whether this has an imprint on social inclusion or instead, connections remain assortative is less explored. In this paper, we aim to better understand income sorting in social networks inside cities and investigate how commuting distance conditions the online social ties of Twitter users in the 50 largest metropolitan areas of the United States. An above‐median commuting distance in cities is linked to more diverse individual networks, moreover, we find that longer commutes are associated with a nearly uniform, moderate reduction of overall social tie assortativity across all cities. This suggests a universal relation between long‐distance commutes and the integration of social networks. Our results inform policy that facilitating access across distant neighborhoods can advance the social inclusion of low‐income groups.
EPS

Repeated collaboration of inventors across European regions

Tóth, G., Juhász, S., Elekes, Z., and Lengyel, B.

European Planning Studies, 2021

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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-inventor 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 a collaboration, but only when geographical proximity is present as an enabler. Hence, repeated inter-regional co-inventor collaborations are more likely to revert to spatial clustering, contributing to the fragmentation of the European Research Area.
SBE

Spinoffs and tie formation in cluster knowledge networks

Juhász, S.

Small Business Economics, 2021

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It is generally acknowledged that in order to have access to locally accumulated industrial knowledge, firms have to collaborate and take part in cluster knowledge networks. This study argues that the inherited capabilities of spinoff enable them to cooperate and exchange knowledge more easily and to gain more from positive knowledge externalities in clusters. The basis of the analysis is a relational dataset on a printing and paper product cluster in Hungary, and I use exponential random graph models to explain the formation of knowledge ties. I demonstrate that besides geographical proximity, ownership similarity and network structural effects, being a spinoff company enhances tie formation in the local network. Results suggest that spinoffs are indeed more likely to collaborate and take advantage of knowledge concentration.

2020

PIRS

Explaining the dynamics of relatedness: The role of co-location and complexity

Juhász, S., Broekel, T., and Boschma, R.

Papers in Regional Science, 2020

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Relatedness has become a key concept for studying the diversification of firms, regions and countries. However, studies tend to treat relatedness as being time-invariant or, alternatively, consider its evolution as exogenously given. This study argues that relatedness is inherently dynamic and endogenous to technological and economic developments. Using patent data, we test the extent to which relatedness between technologies developed along co-location and differences in technological complexity in 1980–2010. Our results show that co-located technologies are more likely to become related over time. Moreover, our results suggest that co-location and complexity of technologies are conducive to the intensification of relatedness over time.
PLOS

Brokering the core and the periphery: Creative success and collaboration networks in the film industry

Juhász, S., Tóth, G., and Lengyel, B.

PLOS One, 2020

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In collaboration-based creative industries, such as film production, creators in the network core enjoy prestige and legitimacy that are key for creative success. However, core creators are challenged to maintain diverse access to new ideas or alternative views that often emerge from the network periphery. In this paper, we demonstrate that creators in the network core can increase the probability of their creative success by brokering peripheral collaborators to the core. The argument is tested on a dynamic collaboration network of movie creators constructed from a unique dataset of Hungarian feature films for the 1990–2009 period. We propose a new way to capture brokers’ role in core/periphery networks and provide evidence that being in the core and at the same time bridging between the core and the periphery of the network significantly increases the likelihood of award winning.

2019

2018

JEG

Creation and persistence of ties in cluster knowledge networks

Juhász, S., and Lengyel, B.

Journal of Economic Geography, 2018

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Knowledge networks are important to understand learning in industry clusters but surprisingly little is known about what drives the formation, persistence and dissolution of ties. Applying stochastic actor-oriented models on longitudinal relational data from a mature cluster in a medium-tech industry, we show that triadic closure and geographical proximity increase the probability of tie creation but does not influence tie persistence. Cognitive proximity is positively correlated to tie persistence but firms create ties to cognitively proximate firms only if they are loosely connected through common third partners. We propose a micro-perspective to understand how endogenous network effects, cognitive proximity of actors and their interplay influence the evolutionary process of network formation in clusters.