We are excited to announce a series of presentations this semester hosted by the SUNLab which will focus on urban dynamics, behavioral big data, and experienced inequality in cities.
We’ll also be hosting a film screening and panel Q&A on May 1st of the documentary Join or Die. Please RSVP here!
We’re very grateful to the visitors who will be sharing their research with us and look forward to seeing everyone at these events!
Upcoming Events:
Dean Eckles (MIT) – Long ties and tendencies toward triadic closure
- When: Friday, March 7th @ 1:30 to 2:30 pm
- Where: 11th Floor, 177 Huntington Ave
Qi “Ryan” Wang (Northeastern) – Urban Mobility, Inequality, and Environmental Justice: Insights from Big Data
- When: Thursday, March 20th @ 1:00 to 2:00 pm
- Where: 11th Floor, 177 Huntington Ave
Dan O’Brien (Northeastern) – The Pointillistic City
- When: Thursday April 17th 1:30 to 2:30 pm
- Where: 11th Floor, 177 Huntington Ave
Film Screening + Panel Q&A – Join or Die – A documentary film about Prof. Robert Putnam’s “Bowling Alone” theory
- When: Thursday, May 1st @ 5:30 to 8:30 pm
- Where: Conference Room 440, Egan Research Center (Main Campus)
- There will be refreshments. Please RSVP here!
Arianna Salazar-Miranda (Yale) – Urban Mobility, City Structure, and Segregation
- When: Friday May 29th @ 1:00 to 2:00 pm
- Where: 11th Floor, 177 Huntington Ave
Full details of the presentations
Dean Eckles
William F. Pounds Associate Professor of Management and Associate Professor of Marketing, MIT Sloan
Long ties and tendencies toward triadic closure
Empirical social networks are characterized by a high degree of triadic closure (i.e. transitivity, clustering), whereby network neighbors of the same individual are also likely to be directly connected. It is unknown to what degree this results from dispositions to form such relationships (i.e. to close open triangles) per se or whether it reflects other processes, such as homophily and more opportunities for exposure.
These are difficult to disentangle in many settings, but in social media not only can they be decomposed, but platforms frequently make decisions that can depend on these distinct processes. Using a field experiment on social media, we randomize the existing network structure that a user faces when followed by a target account that we control, and examine whether they reciprocate this tie formation.
Being randomly assigned to have an existing tie to an account that follows the target user increases tie formation by 35%. Through multiple control conditions, we attribute this effect specifically to the presence of a potential mutual follower.
These results indicate a substantial role for dispositions toward triadic closure, which platforms can leverage in encouraging tie formation, with implications for network structure and the diffusion of information in online networks.
Qi “Ryan” Wang
Associate Professor and Vice Chair for Research, Civil and Environmental Engineering, Northeastern University
Urban Mobility, Inequality, and Environmental Justice: Insights from Big Data
Cities today face mounting challenges, from large-scale crises and climate change to the needs of aging populations. These forces profoundly shape human mobility, influencing how people move, interact, and access essential services.
This talk examines the interplay between urban mobility, environmental justice, and social inequality, leveraging research on mobility data, air quality exposure, and accessibility disparities.
Through case studies such as the BostonWalks study, we explore how movement patterns contribute to unequal pollution exposure, disparities in service access, and resilience to external shocks such as COVID-19 and extreme weather events.
By integrating mobility analytics with environmental and demographic data, this work reveals structural inequities in urban space and highlights how marginalized communities often bear a disproportionate burden.
Daniel T. O’Brien
Professor of Public Policy and Urban Affairs and Criminology and Criminal Justice, Northeastern University
The Pointillistic City
The Pointillistic City extends the classic observation that “neighborhoods matter” for health and well-being. It argues that we must also pay attention to other geographic scales we live within—including streets within neighborhoods and even individual properties.
This perspective is analogous to a pointillistic painting, composed of dots within objects and objects within a full image. The pointillistic perspective surfaces microspatial inequities: disparities between people living within the same neighborhood.
The book illustrates this perspective through civic research projects examining the impact of problem properties on public safety and the role of hyperlocal environmental hazards such as urban heat islets.
It concludes with guidance for designing policies and practices that address microspatial inequities and emphasizes putting cutting-edge data in the hands of communities.
Arianna Salazar-Miranda
Assistant Professor of Urban Planning and Data Science, Yale University
Urban Mobility, City Structure, and Segregation
This talk brings together three papers that use GPS mobility data to study how a city’s spatial configuration and size shape mobility and social outcomes.
The research shows that Americans routinely travel far from home—only 14% of daily consumption trips occur within walking distance. As cities grow, individuals maintain roughly constant daily travel times regardless of city size.
Cities adapt through densification, the development of multiple centers, and investments in faster infrastructure.
The talk concludes by examining how these spatial adaptations influence segregation. While long-distance trips can increase opportunities for interaction, their effect depends on the spatial structure of cities: less spatially clustered cities tend to promote integration more effectively.