Now We’re Talking: Better Deliberation Groups through Submodular Optimization


  • Jake Barrett University of Edinburgh
  • Kobi Gal University of Edinburgh Ben-Gurion University of the Negev
  • Paul Gölz Harvard University
  • Rose M. Hong Harvard University
  • Ariel D. Procaccia Harvard University



GTEP: Social Choice / Voting, SO: Applications


Citizens’ assemblies are groups of randomly selected constituents who are tasked with providing recommendations on policy questions. Assembly members form their recommendations through a sequence of discussions in small groups (deliberation), in which group members exchange arguments and experiences. We seek to support this process through optimization, by studying how to assign participants to discussion groups over multiple sessions, in a way that maximizes interaction between participants and satisfies diversity constraints within each group. Since repeated meetings between a given pair of participants have diminishing marginal returns, we capture interaction through a submodular function, which is approximately optimized by a greedy algorithm making calls to an ILP solver. This framework supports different submodular objective functions, and we identify sensible options, but we also show it is not necessary to commit to a particular choice: Our main theoretical result is a (practically efficient) algorithm that simultaneously approximates every possible objective function of the form we are interested in. Experiments with data from real citizens' assemblies demonstrate that our approach substantially outperforms the heuristic algorithm currently used by practitioners.




How to Cite

Barrett, J., Gal, K., Gölz, P., Hong, R. M., & Procaccia, A. D. (2023). Now We’re Talking: Better Deliberation Groups through Submodular Optimization. Proceedings of the AAAI Conference on Artificial Intelligence, 37(5), 5490-5498.



AAAI Technical Track on Game Theory and Economic Paradigms