Dimitrios Diamantaras

A refinement and extension of the no-envy concept☆

Abstract We propose a new criterion of equity in the spirit of Foleys (1967) no-envy concept. We prove the existence of efficient allocations satisfying this criterion for a class of economies containing many for which envy-free and efficient allocations do not exist; when a large set of the latter exists, our criterion selects a small subset of it.

Decentralization of Pareto Optima in Economies with Public Projects, Nonessential Private Goods and Convex Costs

SummaryIn the theory of economies with public goods one usually considers the case in which private goods are essential, i.e., each agent receives a fixed minimum level of utility if he consumes no private goods, irrespective of the public goods consumed. This paper develops the second welfare theorem for economies with public projects and possibly inessential private goods. As a corollary we also derive conditions under which valuation equilibria exist.

On equity with public goods

Existence theorems for envy-free and efficient allocations are derived for economies with public goods. For economies with an arbitrary but finite number of private and public goods, an adaptation of the existence proof of Svensson for private good economies is used. For economies with one private and one public good, a case often studied in theory and applications, two more direct proofs are given, using different conditions and taking advantage of the particularly simple structure of the set of envy-free allocations in this case. These proofs are also shown to apply to the case of excludable public goods with congestion.

Simulating Social Network Formation: A Case-Based Decision Theoretic Model

Social networks depict complex systems as graph theoretic models. The study of the formation of such systems (or networks) and the subsequent analysis of the network structures are of great interest. For information systems research and its impact on business practice, the ability to model and simulate a system of individuals interacting to achieve a certain socio-economic goal holds much promise for proper design and use of cyber networks. We use case-based decision theory to formulate a customizable model of information gathering in a social network. In this model, the agents in the network have limited awareness of the social network in which they operate and of the fixed, underlying payoff structure. Agents collect payoff information from neighbors within the prevailing social network, and they base their networking decisions on this information. Along with the introduction of the decision theoretic model, we developed software to simulate the formation of such networks in a customizable context to examine how the network structure can be influenced by the parameters that define social relationships. We present computational experiments that illustrate the growth and stability of the simulated social networks ensuing from the proposed model. The model and simulation illustrates how network structure influences agent behavior in a social network and how network structures, agent behavior, and agent decisions influence each other.

On the set of Pareto efficient allocations in economies with public goods (

SummaryWe examine the set of Pareto-efficient allocations in economies with public goods. We show that even if preferences are continuous and strongly monotonic, it need not coincide with the set of weakly efficient allocations. We then study topological properties of the Pareto set. We show that it is neither connected nor closed in allocation space. Furthermore, if the public goods are local, the image of the Pareto set in utility space need not be closed or connected. We provide two independent sufficient conditions for the closedness of the Pareto set. The results are directly applicable to private goods economies with joint production. Our results should be of interest for general equilibrium and mechanism design theory; where for example, the properties of the efficient set are important for proving the existence of an equilibrium and for the study of the properties of monotone-path social choice correspondences.

Generalized Samuelson conditions and welfare theorems for nonsmooth economies

Abstract We give intuitive Samuelson conditions for a very general class of economies. Smoothness and monotonicity are not required. We provide necessary and sufficient conditions for all Pareto-efficient allocations, including those on the boundary. We prove that if all agents have a cheaper point, the supporting prices fully decentralize the allocation. We also show first and second welfare theorems as corollaries to the characterization of efficient allocations.

Envy-free and efficient allocations in large public good economies

Abstract In an economy with private and public goods and a continuum of agents, we show that every envy-free and efficient allocation is generated by a public competitive equilibrium from equal endowments (not a Lindahl equilibrium from equal endowments).

Generic Existence of Rational Expectations Lindahl Equilibria

This paper develops several versions of a concept of rational expectations Lindahl equilibrium for economies with private and public goods and linear production, and proves the generic existence of fully revealing rational expectations Lindahl equilibria using only the prices of the private goods as signals. This feature leads to the generic coincidence of all the versions of the equilibrium concept. Copyright 1992 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

Regular public good economies

Abstract This paper defines three concepts of regularity for economies with private and pure public goods, corresponding to the Lindahl, ratio, and balanced linear cost share equilibrium concepts. Each of these regularity properties is shown to be generic.