Subhadip Chakrabarti

A note on networks of collaboration in multi-market oligopolies

In this note, we extend the Goyal and Joshi’s model of collaboration networks in oligopoly to multi-market situations. We examine the incentive of firms to form links and the architectures of the resulting equilibrium networks in this setting. We then present some results on efficient networks.

Nash equilibria of network formation games under consent

We investigate the Nash equilibria of game theoretic models of network formation based on explicit consent in link formation. These so-called “consent models” explicitly take account of link formation costs. We provide characterizations of Nash equilibria of such consent models under both one-sided and two-sided costs of link formation. We relate these equilibrium concepts to link-based stability concepts, in particular strong link deletion proofness.

Spying in Multi-Market Oligopolies

We consider a multimarket framework where a set of firms compete on two interrelated oligopolistic markets. Prior to competing in these markets, firms can spy on others in order to increase the quality of their product. We characterize the equilibrium espionage networks and networks that maximize social welfare under the most interesting scenario of diseconomies of scope. We find that in some situations firms may refrain from spying even if it is costless. Moreover, even though spying leads to increased product quality, there exist situations where it is detrimental to both consumer welfare and social welfare.

A Note on Negative Electoral Advertising: Denigrating Character vs. Portraying Extremism

In this expository note, we extend the model of Harrington and Hess (1996) by incorporating valence advertising. There is a two-candidate electoral contest. Candidates inherit a certain position indicating their ideological platform in an unidimensional policy space. They also inherit a certain valence index which is a comprehensive term for personal traits that are desirable to all voters such as integrity. The candidates can subsequently influence these using negative advertising with regard to both ideological and valence factors. We find that when the available resources are sufficiently small and certain reasonable assumptions are fulfilled, the candidate with the higher initial valence index will run a relatively personal campaign while the candidate with the lower initial valence index will run an ideological campaign.

A Note on Networks of Collaboration in Multi-market Oligopolies

In this note, we extend the Goyal and Joshi’s model of network of collaboration in oligopoly to multi-market situations. We examine the incentive of firms to form links and the architectures of the resulting equilibrium networks in this setting. We also present some results on efficient networks.

Extending Networks of Collaboration to Multi-market Oligopolies

In this article, we extend the Goyal and Joshi’s model (2003) of network of collaboration in oligopoly to multi-market situations. We examine the incentive of firms to form links and the architectures of the resulting networks in this setting. We also present some results on efficient networks.

Partial Cooperation in Location Choice: Salop’s Model with Three Firms

We consider how three firms compete in a Salop location model and how cooperation in location choice by two of these firms affects the outcomes. We consider the classical case of linear transportation costs as a two-stage game in which the firms select first a location on a unit circle along which consumers are dispersed evenly, followed by the competitive selection of a price. Standard analysis restricts itself to purely competitive selection of location; instead, we focus on the situation in which two firms collectively decide about location, but price their products competitively after the location choice has been effectuated. We show that such partial coordination of location is beneficial to all firms, since it reduces the number of equilibria significantly and, thereby, the resulting coordination problem. Subsequently, we show that the case of quadratic transportation costs changes the main conclusions only marginally.

NETWORK TOPOLOGY, HIGHER ORDERS OF STABILITY AND EFFICIENCY

Stable networks of order r where r is a natural number refer to those networks that are immune to coalitional deviation of size r or less. In this paper, we introduce stability of a finite order and examine its relation with efficient networks under anonymous and component additive value functions and the component-wise egalitarian allocation rule. In particular, we examine shapes of networks or network architectures that would resolve the conflict between stability and efficiency in the sense that if stable networks assume those shapes they would be efficient and if efficient networks assume those shapes, they would be stable with minimal further restrictions on value functions.

Labor unions and Nash bargaining using coalition formation games

In this paper we examine the properties of stable coalitions under sequential and simultaneous bargaining by competing labor unions. We do this using the Nash bargaining solution and various notions of stability, namely, Nash, coalitional, contractual and core stability.

Partial Cooperative Equilibria: Existence and Characterization

We study the solution concepts of partial cooperative Cournot-Nash equilibria and partial cooperative Stackelberg equilibria. The partial cooperative Cournot-Nash equilibrium is axiomatically characterized by using notions of rationality, consistency and converse consistency with regard to reduced games. We also establish sufficient conditions for which partial cooperative Cournot-Nash equilibria and partial cooperative Stackelberg equilibria exist in supermodular games. Finally, we provide an application to strategic network formation where such solution concepts may be useful.