Events
Past Event
WED@NICO SEMINAR: Hyejin Youn, Kellogg School "Nested Skills in Labor Ecosystems: A Hidden Dimension of Human Capital"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Hyejin Youn, Associate Professor, Kellogg School of Management, Northwestern University
Title:
Nested Skills in Labor Ecosystems: A Hidden Dimension of Human Capital
Abstract:
Modern economies, characterized by their vast output of goods and services, operate through globally interconnected networks. As economies become more complex, so do these networks, coordinating increasingly diverse portfolios of specialized efforts and knowledge. In this study, we analyze U.S. survey data (2005–2019) to infer an underlying interdependency tree within the fabric of skill portfolios. Hierarchically constructed, this skill tree starts from widely needed, foundational abilities, constituting the root, and extends to highly specialized, niche skills required by select jobs at the extremities. The directionality is defined by the asymmetrical conditional probabilities of the presence of one skill given the existence of another. Examining 70 million job transitions in resumes and national surveys, we observe that individuals tend to delve deeper into these nested specialization paths as they ascend the career ladder to enjoy higher wage premiums. Nevertheless, the role of foundational skills for such ascent remains pivotal; without reinforcing them, the anticipated wage premiums may vanish. Hence, we further differentiate nested skills from others, with the former building on common prerequisites while the latter does not, and analyze disparities in these skill gaps across different geographic locations, genders, and racial/ethnic groups, observing how these variations in absorptive capacity impact wage premiums. Our analysis reveals a growing and concerning fragmentation in the divide between these two skill groups over the past two decades, suggesting further polarization within the job landscape. Our findings highlight the critical role of robust foundational skills as a stepping stone to specialization and the economic advantages it can confer, reinforcing the need for balanced skill development strategies in complex economies.
Speaker Bio:
Hyejin Youn is an Associate Professor at the Kellogg School of Management, and a core faculty at NICO, the Northwestern Institute on Complex Systems. Her research interests are to understand the interplay between technological innovation and socio-economic systems (urbanization, economic diversity and specialization, invention activity, future of work). Her goal is to develop a theoretical, yet empirically grounded, framework that will enable us to turn the increasing volumes of data into scientific insights and well-designed policies, an approach known as computational social science. The mathematical tools and computational methods that are used include scaling theory, spatial analysis (including percolation theory, information theory and fractal dimension analysis), statistics, and network theory.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/97614034362
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, March 13, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Daniel Stouffer, Leibniz Institute "Conceptual and Theoretical Challenges in the Study of Multi-Species Coexistence"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Daniel B. Stouffer, Research Group Leader, Department of Evolutionary and Integrative Ecology, the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
Title:
Conceptual and Theoretical Challenges in the Study of Multi-Species Coexistence
Abstract:
The population dynamics of most ecological communities unfold on temporal scales that cannot be fully studied in the laboratory or field. The generation times of trees, for example, are so long and varied that we may need to wait decades to determine how a whole, interconnected forest community responds to a changing climate. Many researchers thus use models to generate predictions that go beyond the bounds of what is experimentally tractable. To do so, it has become common to follow the "model-paramerisation paradigm". For example, a researcher interested in forest dynamics would not conduct long-term experiments to directly probe whether one tree species is ever competitively excluded by any other(s). Instead, they would use data from shorter-term experiments to estimate the parameters of a presupposed model, and then study whether or not their empirically parameterised model predicts competitive exclusion or coexistence. As powerful as this perspective has proven to be, it routinely hinges on multiple key assumptions that limit its versatility. I will describe recent and ongoing work that challenges these assumptions, while also describing some unexpected hurdles encountered along the way.
Speaker Bio:
Daniel B. Stouffer is a Research Group Leader in the Department of Evolutionary and Integrative Ecology at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany. His group adopts a variety of computational, statistical, and analytical approaches to overcome ecological communities' innate complexity while exploring fundamental biological questions. They work on a variety of topics and systems and are particularly interested in understanding the emergent ecological and evolutionary consequences that arise due to interactions between species.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98364690035
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, May 6, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Hamsa Bastani, Wharton School, University of Pennsylvania "Challenges in Achieving Human-AI Collaboration"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Hamsa Bastani, Associate Professor of Operations, Information, and Decisions, and Statistics and Data Science, Wharton School, University of Pennsylvania
Title:
Challenges in Achieving Human-AI Collaboration
Abstract:
TBA
Speaker Bio:
Hamsa Sridhar Bastani is an Associate Professor of Operations, Information, and Decisions (OID) and Statistics and Data Science at the Wharton School of the University of Pennsylvania, where she co-direct the Wharton Healthcare Analytics Lab. Her research sits at the intersection of machine learning, operations research, and economics. She studies how to design, deploy, and evaluate AI systems that empower human decision-makers and improve societal outcomes.
Professor Bastani aims to combine methodological depth with implementation in consequential environments. She has worked with national governments to deploy algorithms at the country scale for targeted border COVID-19 screening and essential medicine access, and has co-led one of the first large field studies of generative AI tutors in high school mathematics. She studies both the mathematical properties of algorithms and the way people respond to them.
Her research has been published in leading outlets including Nature, Management Science, Operations Research, and PNAS, and has garnered numerous recognitions, including the Wagner Prize for Excellence in Operations Research, the INFORMS Pierskalla Award for best healthcare paper, and the George Nicholson Prize. Previously, she graduated summa cum laude from Harvard in 2012 with an A.M. in physics and an A.B. in physics and mathematics, completed her PhD in Stanford's Electrical Engineering department under the supervision of Mohsen Bayati, and spent a year as a Herman Goldstine postdoctoral fellow at IBM Research.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/99847338986
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, May 13, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Lightning Talks with NU Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
NICO is looking for participants to share 12-15 minute lightning talks on their current research. To sign up, please fill out this short survey. These are open to Northwestern graduate students, postdoctoral fellows, and visiting scholars!
All talks will be given in person at Chambers Hall and this event will also be livestreamed via Zoom.
Speakers will be balanced based on their topics/disciplines in order to provide a broad representation of the research activities at NICO
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98031689779
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, May 20, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)