The paper concerns a model of influence in which agents make their decisions on a certain
issue. We assume that each agent is inclined to make a particular decision, but due to a
possible influence of the others, his final decision may be different from his initial
inclination. Since in reality the influence does not necessarily stop after one step, but
may iterate, we present a model which allows us to study the dynamic of influence. An
innovative and important element of the model with respect to other studies of this
influence framework is the introduction of weights reflecting the importance that one
agent gives to the others. These importance weights can be positive, negative or equal to
zero, which corresponds to the stimulation of the agent by the ‘weighted’ one, the
inhibition, or the absence of relation between the two agents in question, respectively.
The exhortation obtained by an agent is defined by the weighted sum of the opinions
received by all agents, and the updating rule is based on the sign of the exhortation. The
use of continuous variables permits the application of differential equations systems to
the analysis of the convergence of agents’ decisions in long-time. We study the dynamic of
some influence functions introduced originally in the discrete model,
e.g., the majority and guru influence functions, but the approach
allows the study of new concepts, like e.g. the weighted majority
function. In the dynamic framework, we describe necessary and sufficient conditions for an
agent to be follower of a coalition, and for a set to be the boss set or the approval set
of an agent. equations to the influence model, we recover the results of the discrete
model on on the boss and approval sets for the command games equivalent to some influence
functions.