joint with Segismundo S. Izquierdo and Dunia López-Pintado

Consider a population of individuals who can be either infected or not infected. The infected state may represent catching a disease, but it may also be interpreted in the broader context of contagion processes as e.g. the adoption of the latest technology, or the state of active participation in the classroom. Individuals abandon the infected state (i.e., become healthy) with a certain probability, and may become infected again (or adopt the latest technology, or gain motivation in the classroom) if they meet an infected individual. Some individuals are less prone to be infected than other individuals –either because they have a lower propensity to catch the disease when meeting an infected individual or because they enjoy a higher propensity to heal when they are infected. These different individual propensities define two groups: the susceptible group and the resistant group. The susceptible group has a greater natural propensity to be infected than the resistant group, which naturally presents a lower (dynamically stable) infection level.
In this paper we analyse the effect that different levels of interaction between the two groups (i.e. mixing) has on the overall infection level, as well as on each group’s infection level. As we increase the mixing of the two groups, one would naturally expect the infection level in the susceptible group to decrease, and the opposite effect on the resistant group. However, the infection level in the resistant group may also decrease when mixing increases. This implies, in particular, that mixing can help both groups achieve lower rates of infection, and that some levels of mixing are Pareto inefficient.

VIEW PAPER