Economic Institutions and Stability: A Network Approach

We consider a network economy in which economic agents are connected within a structure of value-generating relationships. Agents are assumed to be able to participate in three types of economic activities: autarkic self-provision; binary matching interactions; and multi-person cooperative collaborations. We introduce two concepts of stability and provide sufficient and necessary conditions on the prevailing network structure for the existence of stable assignments, both in the absence of externalities from cooperation as well as in the presence of size-based externalities. We show that institutional elements such as the emergence of socioeconomic roles and organizations based on hierarchical leadership structures are necessary for establishing stability and as such support and promote stable economic development.Cooperatives;Networks;Clubs;Network economies;Stable matchings

Complex networks analysis in socioeconomic models

This chapter aims at reviewing complex networks models and methods that were either developed for or applied to socioeconomic issues, and pertinent to the theme of New Economic Geography. After an introduction to the foundations of the field of complex networks, the present summary adds insights on the statistical mechanical approach, and on the most relevant computational aspects for the treatment of these systems. As the most frequently used model for interacting agent-based systems, a brief description of the statistical mechanics of the classical Ising model on regular lattices, together with recent extensions of the same model on small-world Watts-Strogatz and scale-free Albert-Barabasi complex networks is included. Other sections of the chapter are devoted to applications of complex networks to economics, finance, spreading of innovations, and regional trade and developments. The chapter also reviews results involving applications of complex networks to other relevant socioeconomic issues, including results for opinion and citation networks. Finally, some avenues for future research are introduced before summarizing the main conclusions of the chapter.Comment: 39 pages, 185 references, (not final version of) a chapter prepared for Complexity and Geographical Economics - Topics and Tools, P. Commendatore, S.S. Kayam and I. Kubin Eds. (Springer, to be published

The Networked Common Goods Game

We introduce a new class of games called the networked common goods game (NCGG), which generalizes the well-known common goods game. We focus on a fairly general subclass of the game where each agent's utility functions are the same across all goods the agent is entitled to and satisfy certain natural properties (diminishing return and smoothness). We give a comprehensive set of technical results listed as follows. * We show the optimization problem faced by a single agent can be solved efficiently in this subclass. The discrete version of the problem is however NP-hard but admits an fully polynomial time approximation scheme (FPTAS). * We show uniqueness results of pure strategy Nash equilibrium of NCGG, and that the equilibrium is fully characterized by the structure of the network and independent of the choices and combinations of agent utility functions. * We show NCGG is a potential game, and give an implementation of best/better response Nash dynamics that lead to fast convergence to an $\epsilon$-approximate pure strategy Nash equilibrium. * Lastly, we show the price of anarchy of NCGG can be as large as $\Omega(n^{1-\epsilon})$ (for any $\epsilon>0$), which means selfish behavior in NCGG can lead to extremely inefficient social outcomes

Stability, Specialization and Social Recognition

Yang s theory of economic specialization under increasing returns to scale (Yang 2001) is a formal development of the fundamental Smith-Young theorem on the extent of the market and the social division of labor.In this theory specialization and, thus, the social division of labor is firmly embedded within a system of perfectly competitive markets.This leaves unresolved whether and how such development processes are possible in economies based on more primitive, nonmarket organizations.In this paper we introduce a general relational model of economic interaction.Within this non-market environment we discuss the emergence of economic specialization and ultimately of economic trade and a social division of labor.We base our approach on three stages in organizational development: the presence of a stable relational structure; the presence of relational trust and subjective specialization; and, finally, the emergence of objective specialization through the social recognition of subjectively defined economic rolesnetworks;stability;social division of labor;specialization

Eigenvalues and the diameter of graphs

Graphs;Eigenvalues

The Formation of Financial Networks

Modern banking systems are highly interconnected. Despite their various benefits, the linkages that exist between banks carry the risk of contagion. In this paper we investigate how banks decide on direct balance sheet linkages and the implications for contagion risk. In particular, we model a network formation process in the banking system. Banks form links order to reduce the risk of contagion. The network is formed endogenously and serves as an insurance mechanism. We show that banks manage to form networks that are resilient to contagion. Thus, in an equilibrium network, the probability of contagion is virtually 0.Financial Stability, Network Formation, Contagion Risk

Repeated games and networks

The chapter provides an overview of recent results on infinitely repeated games in which monitoring and interactions are local. The chapter surveys Folk Theorems for games with local monitoring, and results characterizing optimal punishments in separable local public goods games. The relationship between the monitoring structure and the equilibrium correspondence is a key topic of enquiry. Results clarify the roles played by contagion, ostracism, and communication in shaping equilibrium outcomes. Understanding how network measures of social cohesion and of information diffusion can affect trust in communities is the main applied aim of the literature.</p