Title
Bayesian Evidence Accumulation on Social Networks
Abstract
To make decisions we are guided by the evidence we collect and the opinions of friends and neighbors. How do we combine our private beliefs with information we obtain from our social network? To understand the strategies humans use to do so, it is useful to compare them to observers that optimally integrate all evidence. Here we derive network models of rational (Bayes optimal) agents who accumulate private measurements and observe the decisions of their neighbors to make an irreversible choice between two options. The resulting information exchange dynamics has interesting properties: When decision thresholds are asymmetric, the absence of a decision can be increasingly informative over time. In a recurrent network of two agents, the absence of a decision can lead to a sequence of belief updates akin to those in the literature on common knowledge. On the other hand, in larger networks a single decision can trigger a cascade of agreements and disagreements that depend on the private information agents have gathered. Our approach provides a bridge between social decision making models in the economics literature, which largely ignore the temporal dynamics of decisions, and the single-observer evidence accumulator models used widely in neuroscience and psychology.
Year
DOI
Venue
2020
10.1137/19M1283793
SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS
Keywords
DocType
Volume
decision making,probabilistic inference,social networks,stochastic dynamics,first passage time problems
Journal
19
Issue
ISSN
Citations 
3
1536-0040
0
PageRank 
References 
Authors
0.34
3
4
Name
Order
Citations
PageRank
Bhargav R. Karamched101.35
Simon Stolarczyk200.68
Zachary P. Kilpatrick310111.58
Kresimir Josic412316.63