We study policies that are aimed at retaining a migrant workforce in a Gulf State while introducing a tax on migrant earnings. We single out Qatar as a case study. We consider two types of migrants: target migrants, and non-target migrants. If migrants are target migrants, we show that in order...

In a haystack-type representation of a heterogeneous population that is evolving according to a payoff structure of a prisoner's dilemma game, migration is modeled as a process of swapping individuals between heterogeneous groups of constant size after a random allocation fills the haystacks,...