POPNET Connects with Bas Hofstra
2023-05-22 11:00 - 12:00 (Europe/Amsterdam)
This seminar is hybrid. Please register to attend the seminar online or on-site via the button. You will receive a link to the virtual meeting via email or a confirmation containing the on-site location

Academic Migration: Interdisciplinary Hierarchy, Closure, or Similarity?

The last two decades have seen a surge in research initiatives in many scientific fields surrounding interdisciplinarity. This has spawned many interdisciplinary research centers on US university campuses supported by billions of raised university or federal grant money to educate students as well as to facilitate interdisciplinary exchange and collaborations between faculty. This is often led by the belief that interdisciplinary exchange in science pushes research fields forward and accelerates breakthrough discovery. Interdisciplinary scientific collaboration is argued to pull together diverse insights from multiple bodies of knowledge, is unrestricted by disciplinary boundaries or semantics, and can draw from a larger methodological tool set.

Yet in spite of the push for interdisciplinary exchanges, there is surprisingly little empirical knowledge on its prevalence, patterning, or determinants. This is remarkable, because prior work shows that the social fabric of science itself is inherently shaped by exchanges of ideas, knowledge, and scholars themselves. Here, we focus on the latter and study scholarly hiring between disciplines. How prevalent are such exchanges between disciplines and how did this develop over time? And, more importantly, what determines the emergence of these interdisciplinary exchange structures: do some disciplines disproportionately place faculty in other disciplines, do disciplines cluster in such a hiring network, or are interdisciplinary hires mostly explained by how intellectually similar discipline are? These questions motivate the main goals of this study: identifying patterns of interdisciplinary exchange and explaining the emergence and persistence of these network structures.

We build on and extend prior work, particular the branches of literature on interdepartmental faculty hiring. Hiring often involves exchange indicative of implicit judgment; when one department hires a graduate student of another as faculty, there is a positive assessment of the graduate department that places the student. The assortment of these dyadic exchanges across disciplines represent migration networks of scholars that illuminate disciplinary hierarchy, clustering, and similarity. Our study empirically considers these network dynamics, thus providing insight into which disciplines wield the most influence in knowledge and scholarly exchange and why.

Our empirical site contains a realized scientific migration market of approximately 1.03 million records of nearly all US PhD students and corresponding metadata – names, supervisors, disciplines, and so forth – from their PhD theses (1980-2010). These data capture a wide cross-section of scholarly disciplines (N = 51) PhD-granting universities (N = 221), and departments (N = 8,205). What is particularly useful about this database is that it allows us to follow PhD recipients through time in a near-closed system of PhD recipients and their scholarly careers moving onward, thus showing the interdisciplinarization – which disciplines place students where and why? – of US academia. We analyze these interdisciplinary exchanges through a series of stERGMs that include nodal (discipline size, popularity), dyadic (natural language processing measures of intellectual distance between disciplines, field homophily), and closure dynamics.

About Bas Hofstra

Bas Hofstra is Assistant Professor at Radboud University’s Department of Sociology. His work orbits the study of diversity, stratification, and innovation. It captures longitudinal systems of social and cultural exchange: from the gestation and birth of networks, careers, ideas, or innovations, to their use, up until their eventual cessation. As such, his work strives for three interrelated goals: (i) answering substantive questions on causes and effects of social networks, while (ii) contributing to social theory, and (iii) using computational methods and big data. His research appeared (among others) in PNAS, American Sociological Review, Social Forces, Social Networks, and Nature Human Behaviour, and was honored with several grants and awards.

The anatomy of a population-scale social network
2023-06-29 18:40 - 20:00
On Thursday 29 June, POPNET Postdoctoral Researcher Eszter Bokányi will present her work on “The anatomy of a population-scale social network” at Sunbelt 2023, which will take place in Portland, Oregon.

Social-economic segregation in a Population-Scale Social Network
2023-06-29 18:40 - 20:00
On Thursday 29 June, POPNET PhD candidate Yuliia Kazmina will present her work on “Social-economic segregation in a Population-Scale Social Network” at Sunbelt 2023, which will take place in Portland, Oregon.

The small-world structure of a population-scale social network
2023-06-29 18:40 - 20:00
On Thursday 29 June, POPNET PI Frank Takes will present his work on “The small-world structure of a population-scale social network” at Sunbelt 2023, which will take place in Portland, Oregon.

Node anonymity in networks: The infectiousness of uniqueness
2023-06-29 21:30 - 22:50
On Thursday 29 June, POPNET PhD candidate Rachel de Jong will present her work on “Node anonymity in networks: The infectiousness of uniqueness” at Sunbelt 2023, which will take place in Portland, Oregon.

Promise and perils of population-scale social network analysis
2023-10-26 15:30 - 17:00
On Thursday 26 October, POPNET PI Frank Takes will present his work online for the IAS lecture series of the Institute for Analytical Sociology in Norrköping, Sweden.

Abstract

A relatively recently emerged line of research is dedicated to harnessing large-scale population register data to address enduring questions within the realm of social science. In this presentation, we will specifically delve into the network dimension of such data, with a focus on data from the POPNET project, covering over 17 million people (i.e., the entirety of the Netherlands) and their ca. 800M family, household , school, work and next-door neighbor connections. We highlight the potential inherently present in this type of curated and comprehensive social network data through illustrative examples of results related to topics such as social capital, segregation, and migration. Furthermore, we will explore several methodological considerations and challenges related to under- and oversampling of individual connections through opportunity structures, including findings on the veracity of skewed degree distributions in the real world. We also highlight network-structure related concerns w.r.t. privacy, in particular disclosure risk and more in general the anonymization of network data for scientific research.

POPNET presents their work during Sunbelt Conference 2024
2024-06-26 00:00 - 2024-06-29 23:59
POPNET proudly joins the 44th edition of the Sunbelt Conference in Edinburgh from 24th June to June 30th 2024. The Sunbelt Conference is part of the International Network for Social Network Analysis (INSNA), providing an interdisciplinary venue for social scientists, mathematicians, computer scientists, ethnologists, and others to present current work in the area of social networks.

Exploring Social Network Analysis

In alignment with POPNET’s aim to unlock longitudinal social network data on the Dutch population, this year theme of the Sunbelt 2024 is ‘Networks and Resilience’. Throughout the conference, various members of POPNET will give talks in the field of social network analysis. Social capital, network clustering, and family networks are just a few examples of the topics that will be covered at Sunbelt 2024.

Find below a list of the titles they will present during the conference:

26 June, 14:30: “Is Social Capital Good for you?”, by Heemskerk, Eelke; Takes, Frank W. .

26 June, 14:30: “Social Network Determinants of Economic Prosperity in a Longitudinal Population-scale Social Network”, by Kazmina, Yuliia; Heemskerk, Eelke; Bokanyi, Eszter; Takes, Frank W. .

27 June, 8:30: “Parenthood status of siblings, half-siblings and cousins and entry into parenthood. A horizontal kinship network approach”, by de Bel, Vera; Artamonova, Alyona; Hiraoka, Takayuki; Danielsbacka, Mirkka; Tanskanen, Antti; van Duijn, Marijtje.

27 June, 10:40: “Large and small-scale dynamics of a longitudinal population-scale social network”, by Bokanyi, Eszter; Kazmina, Yuliia; van der Kooij, Emilia; Takes, Frank; Heemskerk, Eelke.

29 June, 14:00: “Connectivity and community structure of online and register-based population-scale social networks”, by Menyhért, Márton; Bokányi, Eszter; Corten, Rens; Heemskerk, Eelke; Kazmina, Yuliia; Takes, Frank W. .

Parenthood status of siblings, half-siblings and cousins and entry into parenthood. A horizontal kinship network approach
2024-06-27 08:30 - 10:10
On June 27, Vera de Bel, Alyona Artamonova, Takayuki Hiraoka, Mirkka Danielsbacka, Antti Tanskanen, Marijtje van Duijn will present their work on “Parenthood status of siblings, half-siblings and cousins and entry into parenthood. A horizontal kinship network approach” at Sunbelt 2024, which will take place in at Heriot-Watt University, Edinburgh.

Abstract

Horizontal kinship ties last a lifetime, and life-course transitions of horizontal kin are known to be interconnected. Prior research, with a focus on siblings, has demonstrated their influence on various life events, including home leaving (Her, Vergauwen, & Mortelmans, 2022), marriage and divorce behavior (Buyukkececi & Leopold, 2021), and fertility (Buyukkececi & Leopold, 2021; Lyngstad & Prskawetz, 2010). However, siblings are just one example of individuals’ horizontal kin, and the impact extends to half-siblings and cousins, shaping both individual trajectories and those of their relatives. Moreover, the influence of horizontal kin may vary based on factors such as the degree of relatedness (full siblings, half-siblings, or cousins), kin’s gender ((half-)brothers, (half-)sisters, male or female cousins), and lineage (paternal or maternal side of the family). This study seeks to analyze the complete horizontal kinship network to understand how individuals’ entry into parenthood is associated with the parenthood status of their horizontal kin. More specifically, the study examines whether 1) close kin compared to more distant kin, 2) female compared to male kin, and 3) maternal compared to paternal kin have a stronger influence on an individual’s entry into parenthood. Utilizing unique registry data that documents the kinship networks of the entire Dutch (van der Laan, de Jonge, Das, Te Riele, & Emery, 2022) and Finnish population, the study will employ a multi-level model considering the nested structure and dependence of relationships (Snijders & Bosker, 2012; van Duijn, 2013). First results and a comparison between the Dutch and Finnish contexts will be presented.

Contacts in contexts: A population-scale social network approach to the study of close intergroup social ties
2024-06-28 17:20 - 19:00
On June 28, Nicolás Soler, PhD Candidate (Erasmus University Rotterdam) and POPNET Fellow, will give a lecture about a new approach that investigates social context in intergroup social ties across multiple contexts.

Abstract

Close intergroup social ties provide fertile ground to cultivate mutual trust and tolerance. Social context shapes the opportunities to form such ties, but what is exactly the relationship between opportunities and realised intergroup social ties? When assessing the importance of social context, previous quantitative research has faced a trade-off between generalisability and granularity in data collection. The challenge is to study the relevance of social context in intergroup social ties across multiple contexts, in detail, and at a large scale. To do so, we map social context using newly available population-scale social network data from the Netherlands. We link them to survey data on close intergroup social ties. We showcase our novel approach by investigating which contexts sustain close social ties between immigrants and natives, i.e. individuals born and residing in the Netherlands. Our results confirm that natives who have more opportunities to interact with immigrants are more likely to have a close intergroup social tie with them. We find that this effect is stronger when the opportunities for intergroup interaction arise in private rather than public contexts. We also find that natives with at least one immigrant parent are important brokers in this type of intergroup social ties.

Co-authored with Eelke and Yuliia. Presented as poster presentation.

Increasing mobility is linked to decreasing cohesion of personal networks overthe lifecourse of an entire population
2024-10-18 10:00 - 19:00
On October 18, Eszter Bokányi will present her work on “Increasing mobility is linked to decreasing cohesion of personal networks over the lifecourse of an entire population” at the Dutch NetSci Symposium, which will take place at Eindhoven University of Technology.

Abstract

Growing accessibility between places and a changing society foster higher human mobility both daily and long-term, which results in an increased social connectivity between faraway places. Thus, geographic displacement creates new connections and at the same time rearranges the existing spatial structure of social networks. Both of these mechanisms are little understood in the existing literature of social network formation processes. Moreover, up until now, it has also been a challenge to systematically follow the temporal evolution of an entire population’s social network structure.

In this work, we use a unique longitudinal population-scale network dataset sourced from Statistics Netherlands. This network contains family, work, school, household, and next-door neighbor connections derived from administrative registers, that together constitute a multilayer social opportunity structure for all residents of the Netherlands between 2009 and 2022. We follow the patterns of individuals’ network surroundings over time, and measure size, closure, and geographical dispersion of ego networks. Size is captured by degree, closure by excess closure [1], which is based on the node clustering coefficient. Geographical dispersion is given by the average distance from network neighbors, and the average share of network neighbors in the same municipality or the same next-door neighborhood as the ego.

The three findings presented in this work are that while the average size of ego networks stays stable over the observed period, average closure drops by as much as 10%, and the average distance from network neighbors grows, while the average share of network neighbors in the same geographic area decreases. We use multivariate regressions to show that the observed decrease in the closure is significantly linked to the growing geographic dispersion, thus, the increasing daily and long-term mobility of people. We control for demographic and socio-economic background including the age, migrant generation, income, and whether people attend school and have employment. The regressions confirm that beyond degree and demographics, variables that capture people’s mobility are linked to the opening up of individual networks.

This work is the first of its kind that aims to map the temporal network of an entire population structure comprehensively. As such, it offers a starting point for a wide variety of impactful network science research at the level of a complete population.

[1] Bokányi, E., Heemskerk, E. M., & Takes, F. W. (2023). The anatomy of a population-scale social network. Scientific Reports, 13(1), 9209.

The Closing Window? Network Determinants of Economic Prosperity in a Longitudinal Population-scale Social Network
2024-10-18 10:00 - 19:00
On October 18, Yuliia Kazmina will present her work on “The Closing Window? Network Determinants of Economic Prosperity in a Longitudinal Population-scale Social Network” at the Dutch NetSci Symposium, which will take place at Eindhoven University of Technology.

Abstract

This work presents a comprehensive longitudinal exploration of trends of socio- economic segregation and inequalities across a span of a recent decade, aiming to reveal their impact on the prospects for upward mobility.

Utilizing population-scale social network register data on all residents of the Netherlands, the research delves into the shifting patterns of income and wealth distributions, offering an in-depth overview of their longitudinal trends and interplay. We juxtapose the evolving dynamics of income and wealth accumulation against a specific aspect of social network structure: segregation patterns along the socio-economic status dimension. To unravel the drivers behind observed macro-trends of segregation and inequality, we distinguish various relevant subgroups within the population as defined by their socio-economic background and social network position. Through comparative analysis across diverse socio-economic strata, we identify the key social network determinants contributing to individuals’ economic prosperity and explore how these influences vary across the spectrum of income and wealth distribution.

The study leverages register data from the Netherlands covering the country’s whole population and providing information on one’s socio-economic standing as well as comprehensive mapping of social networks. The relational aspect of register data sheds light on formal links such as kinship, neighbors, classmates, colleagues, and household members. Methodologically, the study employs a mix of supervised and unsupervised machine learning to analyze longitudinal patterns of segregation and economic inequalities. We first employ clustering analysis to define common trajectories of economic development expressed through a combination of income change as well as accumulation of wealth and debt. We then relate these trajectories to the socioeconomic network composition of these individuals with a particular focus on income and wealth assortativity as well as average income and wealth distance to alters while controlling for the size of the social network.

In contrast to recent work on social capital by Chetty et al., we contend that the key factor for improving economic performance among the lower end of the prosperity distribution isn’t merely low segregation and high economic connectedness. Rather, it lies in having a significant proportion of more affluent contacts, while ensuring that the prosperity gap is within an optimal range. While having somewhat wealthier contacts can be advantageous, once the prosperity gap becomes too wide, its predictive power may diminish or even have a negative impact. Therefore, we anticipate a concave relationship between the positive prosperity gap with alters and enhanced economic performance,especially for those at the lower end of the prosperity distribution.

Our contribution lies not only in comprehensively mapping dynamics of segregation vs economic inequalities on the country level but also in providing micro-analysis of the drivers that contribute to the observed macro outcomes. This interdisciplinary approach enables a comprehensive perspective on how individual pathways to economic successare embedded within a broader structural framework.

References1. Chetty, R., Jackson, M.O., Kuchler, T. et al. Social capital I: measurement and associationswith economic mobility. Nature 608, 108–121 (2022). https://doi.org/10.1038/s41586-022-04996-42. Chetty, R., Jackson, M.O., Kuchler, T. et al. Social capital II: determinants of economicconnectedness. Nature 608, 122–134 (2022). https://doi.org/10.1038/s41586-022-04997-3

POPNET Connects with Jolien Cremers
2024-10-21 14:00 - 15:00
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Unveiling the Social Fabric: A Temporal, Nation-Scale Social Network and its Characteristics

Social networks shape individuals’ lives, influencing everything from career paths to health. Statistics Denmark and Copenhagen Centre for Social Data Science developed a registry-based, multi-layer and temporal network of the entire Danish population in the years 2008-2021 (roughly 7.2 mill. individuals). Our network maps the relationships formed through family, households, neighborhoods, colleagues and classmates. Analysis of the network reveals how past connections reappear later in other layers, that the number of relationships aggregated over time reflects the position in the income distribution, and that we can recover canonical shortest path length distributions when appropriately weighting connections.

About Jolien Cremers

Jolien Cremers is Senior Advisor at the Data Science Lab at Statistics Denmark. She is responsible for maintaining and developing the Danish Nation-Scale Social Network data as well as cooperating with outside researchers on projects that use this data. She obtained her Ph.D. in applied statistics for social science from Utrecht University in 2019. Her previous research was on Bayesian methodology for circular statistics as well as applied statistics for longitudinal models of health and other types of registry data.

POPNET Connects with Ana Macanovic (Hybrid)
2024-12-09 11:00 - 12:00
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Limits to Gender Equity in Science Communication (Hybrid)

The public continuously seeks scientific expertise on pressing issues and the scientists are becoming increasingly conscious of the importance of engaging with the public through different media outlets. Understanding and addressing contemporary societal challenges crucially depends on hearing diverse perspectives of a wide variety of scientists. Yet, past research has shown that time in the media spotlight is unequally distributed between researchers belonging to different social groups.

Here we focus on the representation of men and women scientists in the media. To better understand the complex landscape of gender differences in media representation, we present a newly curated and fine-grained dataset, the Dutch Professors in Media database (DPM). DPM contains information on scientific careers, media attention across several media channels, and co-authorship networks of almost 7 thousand full professors in the Netherlands. We start by evaluating gender inequality in professors’ media presence controlling for indicators of their own scientific prominence, as well as the prominence of the collaborators in their scientific network.

We find that women receive significantly less attention than men in printed media, but not in online news and on the social media across most scientific fields. Furthermore, we evaluate the extent to which the features of one’s collaboration networks, as well as the processes of cumulative advantage, are associated with (gender differences in) professors’ consecutive media presence.

About Ana Macanovic

Ana Macanovic is a Max Weber Fellow at the European University Institute (EUI) in Florence. Her interests include economic sociology, study of inequalities, and understanding of trust and cooperation in diverse groups. Ana is interested in how structural inequalities arise in societies and how they can be addressed. She has recently worked on gender representation of Dutch professors in newspapers and online media with Bas Hofstra. Currently, Ana is working on several projects examining the accumulation of inequalities and innovation in academia, as well as understanding the predictability of life outcomes of different social groups.

If you wish to attend this event on-site at IAS, please send an email to j.murli@uva.nl.
