A way of explaining unemployment through a wage-setting game

We investigate a duopsonistic wage-setting game in which the firms have a limited number of workplaces. We assume that the firms have heterogeneous productivity, that there are two types of workers with different reservation wages and that a worker's productivity is independent of his type. We show that equilibrium unemployment arises in the wage-setting game under certain conditions, although the efficient allocation of workers would result in full employment.