A multi-agent system for e-barter including transaction and shipping costs

An e-barter multi-agent system consists of a set of agents exchanging goods. In contrast to e-commerce systems, transactions do not necessarily involve the exchange of money. Agents are equipped with a utility function to simulate the preferences of the customers that they are representing. They are grouped into local markets, according to the localities of the corresponding customers. Once these markets are saturated (i.e. no more exchanges can be performed) new agents, representing those local markets, are generated and combined into new markets. By reiteratively applying this process we finally get a global market.Even though a formalism to define e-barter architectures has been already introduced, that framework had a strong drawback: Neither transaction nor shipping costs were considered. In this paper we extend that framework to deal with systems where fees have to be paid to the owner of the system. These fees depend on the goods involved in the corresponding exchanges. In addition, shipping costs have also to be paid. These modifications complicate the setting because the utility that customers receive after exchanging goods is not directly given by the original utility function. That is, the returned utility after an exchange is performed has to be computed as a combination of the former utility and the derived costs. In particular, some exchanges may be disallowed because those costs exceed the increase of utility returned by the new basket of goods.