11. Ownership and Trade in Complex Networks

In this chapter we introduce a networked version of the Possessor’s and Trader’s game, where, among the two basic strategies used in the Hawks-Dove game, hawks (H) and doves (D), it includes two other strategies based on the property of resources: Possession (P), as the right to occupy or possess what one owns; and Trade (T), as the right to buy and sell ownership. The simulations presented in this chapter describe how evolutionary forces, depending on the simulation parameters, allow the emergence of the different type of populations (D, C, P or T) over several complex topologies. The evolution of these populations clearly depends on several parameters as the cost of fighting, the trading values, the network topology, the owner’s probability and, under certain conditions, the neighborhood size. We also study the effect of partner switching (a.k.a. rewiring) to discover that, in all the topologies and conditions analyzed, the results are worse than without rewiring, and the global payoff decreases due to the effect of hawks. We also consider the effect of allowing the agents to accumulate payoff during a certain number of rounds, and we have discovered that the global payoff improves significantly when agents accumulate resources during five rounds or more. Finally, we introduce the possibility to create an informal trading social network, where traders seek for other traders, and connect to them; avoiding the hawks in their own neighborhoods. This trading social network is much more successful for traders, and for the global payoff, than the previous all-to-all attempt.