Vortrag zum Thema "The Limits of Popularity-Based Recommendations, and the Role of Social Ties"


Vortragender: Prof. Dr. Alessandro Panconesi (Sapienza University of Rome)

Titel: The Limits of Popularity-Based Recommendations, and the Role of Social Ties

Ort: Fachbereich Computerwissenschaften Institutsgebäude Jakob-Haringer-Str. 2, Itzling, HS T02

Datum: Mittwoch, 31. August 2016, 11:00 Uhr



Recommender systems are increasingly becoming the main gateway between people and
online choices. With their power to influence and shape the market, they are becoming
powerful economic actors. The broad question we are interested in is, to what extent can
they alter a market? Can they determine winners and losers in the market? Can they turn
niche products into hits, and viceversa?
In this paper we introduce a mathematical model that captures some of the salient features
of recommender systems that are based on popularity and that try to exploit social ties
among the users. We show that, under very general conditions, the market always
converges to a steady state, for which we are able to give an explicit form. Thanks to this we
can tell rather precisely how much a market is altered by a recommendation system, and
determine the power of users to influence others. Our theoretical results are complemented
by experiments with real world social networks showing that social graphs prevent large
market distortions in spite of the presence of highly influential users.
Joint work with: Marco Bressan, Stefano Leucci, Prabhakar Raghavan, and Erisa Terolli


Host: Univ.-Prof. Dr. Robert Elsässer