Add to ORKGIn this paper, we present a theorethical model that tries to investigate the observable hysteresis process in the migration dynamic. In the model the migration choice depends not only on the wage differential, but also on a U-shaped benefit function of a community of homogenous ethnic individuals, modelled according to the "theory of clubs". The theoretical results, based on real option theory, explain that the observable "jumps" in the migration flows could depend on two variables: the number of coordinated immigrants and the dimension of the community. In fact, the migration choice is procrastinated until a critical mass is reached. Moreover, some possible rigidities in the adjustment of the district dimension, as regards the optimal leve...