Events Fall 2022

Richard M. Karp Distinguished Lecture — Birds of a Feather Flock Together: How Homophily Leads to Segregation, Inequality, and Inefficiency and What We Can Do About It

Wednesday, September 7th, 2022, 4:00 pm5:00 pm

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Nicole Immorlica (Microsoft Research)


Calvin Lab Auditorium and Zoom

Humans exhibit a strong tendency to associate with those similar to them. This tendency, termed homophily in the social sciences, impacts both the structure of society and its outcomes. In this talk, Nicole Immorlica discusses the mathematics of homophily. She first quantifies its theoretical implications for geographic segregation. We will see that even tolerant societies exhibit segregation, as weak local preferences can have ripple effects with global consequences. This geographic segregation, in turn, reinforces homophily. Immorlica then explores the role of homophily in inequality and economic productivity. She starts from the observation that most employment is driven by referrals. As social networks tend to exhibit homophily, these referrals are also homophilous, perpetuating existing inequality. This inequality, in turn, is harmful to productivity, causing inefficiencies in the economy. She concludes by noting that a one-time affirmative action intervention can both reduce inequality and improve productivity in the long run.


Nicole Immorlica is a senior principal researcher at Microsoft Research New England (MSR NE) where she leads the economics and computation group.  She is also chair of SIGecom, the ACM Special Interest Group on Economics and Computation, which fosters world-class research in this interdisciplinary field through conferences, awards, and mentorship programs.  She received her BS, MEng and PhD in theoretical computer science from MIT in Cambridge, MA.  She joined MSR NE in 2012 after completing postdocs at Microsoft in Redmond, WA and Centruum vor Wiskunde en Informatics (CWI) in Amsterdam, Netherlands, and a professorship in computer science at Northwestern University.  Nicole's research interest is in the design and operation of sociotechnical systems. Using tools and modeling concepts from both theoretical computer science and economics, Nicole hopes to explain, predict, and shape behavioral patterns in various online and offline systems, markets, and games. She is known for her work on social networks, matching markets, and mechanism design.  She is the recipient of a number of fellowships and awards including the Sloan Fellowship, the Microsoft Faculty Fellowship and the NSF CAREER Award.  She has been on several boards including SIGACT, the Game Theory Society, and OneChronos; is an associate editor of Operations Research and Transactions on Economics and Computation, and was program committee member and chair for several ACM, IEEE and INFORMS conferences in her area.

The Richard M. Karp Distinguished Lectures were created in Fall 2019 to celebrate the role of Simons Institute Founding Director Dick Karp in establishing the field of theoretical computer science, formulating its central problems, and contributing stunning results in the areas of computational complexity and algorithms. Formerly known as the Simons Institute Open Lectures, the series features visionary leaders in the field of theoretical computer science, and is geared toward a broad scientific audience. Light refreshments will be available prior to the start of the lecture.

Please note: the Simons Institute regularly captures photos and video of activity around the Institute for use in videos, publications, and promotional materials. 

PDF icon homophily-karplecture.pdf7.9 MB

Please register to attend the lecture, either in person or on Zoom.