2 research outputs found
Opinion dynamics in a three-choice system
We generalize Galam's model of opinion spreading by introducing three
competing choices. At each update, the population is randomly divided in groups
of three agents, whose members adopt the opinion of the local majority. In the
case of a tie, the local group adopts opinion A, B or C with probabilities
alpha, beta and (1-alpha-beta) respectively. We derive the associated phase
diagrams and dynamics by both analytical means and simulations. Polarization is
always reached within very short time scales. We point out situations in which
an initially very small minority opinion can invade the whole system.Comment: To appear in European Physical Journal B. A few errors corrected,
some figures redrawn from the first versio
Consensus Formation in Multi-state Majority and Plurality Models
We study consensus formation in interacting systems that evolve by
multi-state majority rule and by plurality rule. In an update event, a group of
G agents (with G odd), each endowed with an s-state spin variable, is
specified. For majority rule, all group members adopt the local majority state;
for plurality rule the group adopts the local plurality state. This update is
repeated until a final consensus state is generally reached. In the mean field
limit, the consensus time for an N-spin system increases as ln N for both
majority and plurality rule, with an amplitude that depends on s and G. For
finite spatial dimensions, domains undergo diffusive coarsening in majority
rule when s or G is small. For larger s and G, opinions spread ballistically
from the few groups with an initial local majority. For plurality rule, there
is always diffusive domain coarsening toward consensus.Comment: 8 pages, 11 figures, 2-column revtex4 format. Updated version: small
changes in response to referee comments. For publication in J Phys