A DISCRETE-TIME POPULATION DYNAMICS MODEL FOR THE INFORMATION SPREAD UNDER THE EFFECT OF SOCIAL RESPONSE

In this paper, we construct and analyze a mathematically reasonable and simplest population dynamics model based on Mark Granovetter's idea for the spread of a matter (rumor, innovation, psychological state, etc.) in a population. The model is described by a one-dimensional difference equation. Individual threshold values with respect to the decision-making on the acceptance of a spreading matter are distributed throughout the population ranging from low (easily accepts it) to high (hardly accepts). Mathematical analysis on our model with some general threshold distributions (uniform; monotonically decreasing/increasing; unimodal) shows that a critical value necessarily exists for the initial frequency of acceptors. Only when the initial frequency of acceptors is beyond the critical, the matter eventually spreads over the population. Further, we give the mathematical results on how the equilibrium acceptor frequency depends on the nature of threshold distribution.