The prisoner's dilemma (PD) is played by two players in each of two groups. The two groups compete for an external prize whose allocation is determined by the degree of within-group coordination. The experimental evidence supports the predictions of multilevel game theory well.

The article proposes an enabling mechanism for the creation, adjustment and dissolution of governmental units, giving autonomy to each individual as in a direct democracy. The mechanism is designed such that Pareto optimality is possible, in contrast to earlier models which make various...

Fixed numbers of agents equipped with high versus low fighting effort sort themselves into n groups. The group sizes and fractions of strong agents in each group are determined endogenously. The agents compete within and between the groups for their aggregate production which is fixed for the n...