A Formal Framework for E-Barter Based on Microeconomic Theory and Process Algebras

Abstract

In this paper we present a formal framework for the definition of e-barter architectures. By e-barter we mean the possibility of (electronically) exchanging goods without reducing transactions to money. Actually, in our setting, money can be considered just as another good, so that e-barter generalizes seller/buyer architectures. An advantage of e-barter systems, in contrast with most current systems, is that multilateral exchanges can be performed. Customers are first grouped into local markets, according mainly to their localities. Next, a higher order construction allows to compose markets, so that a global market takes a tree-like shape.

In order to methodically build our systems, we consider a process algebraic notation. This allows us to specify all the stages of a system (from customers to markets, markets of markets, etc). We introduce an operational semantics for our language so that exchanges of goods are formally defined. Besides, we use some concepts borrowed from microeconomic theory. Specifically, we consider utility functions (i.e. functions returning the valuation that customers/markets give to goods), exchange of goods, and equilibria.

We will show that the integration of microeconomic theory and process algebras provides two important gains. Firstly, it allows to avoid ambiguity in the understanding of the behavior of systems. Secondly, it gives a scheme to appropriately structure, in a bottom-up way, e-barter systems.

Research supported in part by the CICYT project TIC2000-0701-C02-01.