Peer to peer.

How economic policy uncertainty processes impact on inclusive green growth in emerging industrialized countries: A case study of China

We model social storage systems as a strategic network formation game. We define the utility of each player in the network under two different frameworks, one where the cost to add and maintain links is considered in the utility function and the other where budget constraints are considered. In the context of social storage and social cloud computing, these utility functions are the first of its kind, and we use them to define and analyze the social storage network game. We, then, present the pairwise stability concept adapted for social storage where both addition and deletion of links require mutual consent, as compared to mutual consent just for link addition in the pairwise stability concept defined by Jackson and Wolinsky [35]. Mutual consent for link deletion is especially important in the social storage setting. For symmetric storage networks, we prove that there exists a unique neighborhood size, independent of the number of players, where no pair of users has any incentive to increase or decrease their neighborhood size. We call this neighborhood size as the stability point. We provide some necessary and sufficient conditions for pairwise stability of social storage networks. Further, given the number of players and other parameters, we discuss which pairwise stable networks would evolve. We also show that in a connected pairwise stable network there can be at most one player with neighborhood size one less than (or one more than) the stability point.

Unique Stability Point in Social Storage Networks.

This paper extends the two-way flow model of network formation initiated by Bala and Goyal (Econometrica 68(5):1181–1230, 2000) by allowing for partner heterogeneity. In our model if a player i forms a link with player j, then she pays a cost of c
 j
 and gets benefits of V
 j
 . Our main result consists of the characterization of strict Nash networks. We find that the introduction of partner heterogeneity plays a major role in dramatically increasing the set of strict Nash equilibria. This result differs substantially from what Galeotti et al. (Games Econ Behav 54(2):353–372, 2006) find in the two-way flow connections model of network formation with player heterogeneity.

Strict Nash networks and partner heterogeneity

Impact of a sharing economy on sustainable development and energy efficiency: Evidence from the top ten Asian economies

This paper investigates the impact of link formation between a pair of agents on the resource availability of other agents (that is, externalities) in a social cloud network, a special case of endo...

Externalities in endogenous sharing economy networks

In this paper, we address various types of two-person stochastic games—both zero-sum and nonzero-sum, discounted and undiscounted. In particular, we address different aspects of stochastic games, namely: (1) When is a two-person stochastic game completely mixed? (2) Can we identify classes of undiscounted zero-sum stochastic games that have stationary optimal strategies? (3) When does a two-person stochastic game possess symmetric optimal/equilibrium strategies? Firstly, we provide some necessary and some sufficient conditions under which certain classes of discounted and undiscounted stochastic games are completely mixed. In particular, we show that, if a discounted zero-sum switching control stochastic game with symmetric payoff matrices has a completely mixed stationary optimal strategy, then the stochastic game is completely mixed if and only if the matrix games restricted to states are all completely mixed. Secondly, we identify certain classes of undiscounted zero-sum stochastic games that have stationary optima under specific conditions for individual payoff matrices and transition probabilities. Thirdly, we provide sufficient conditions for discounted as well as certain classes of undiscounted stochastic games to have symmetric optimal/equilibrium strategies—namely, transitions are symmetric and the payoff matrices of one player are the transpose of those of the other. We also provide a sufficient condition for the stochastic game to have a symmetric pure strategy equilibrium. We also provide examples to show the sharpness of our results.

Stationary, completely mixed and symmetric optimal and equilibrium strategies in stochastic games

Social storage systems are becoming increasingly popular compared to the existing data backup systems like local, centralized and P2P systems. An endogenously built symmetric social storage model and its aspects like the utility of each agent, bilateral stability, contentment, and efficiency have been extensively discussed in Mane et. al. (2017). We include heterogeneity in this model by using the concept of Social Range Matrix from Kuznetsov et. al (2010). 
Now, each agent is concerned about its perceived utility, which is a linear combination of its utility as well as others utilities (depending upon whether the pair are friends, enemies or do not care about each other). We derive conditions when two agents may want to add or delete a link, and provide an algorithm that checks if a bilaterally stable network is possible or not. Finally, we take some special Social Range Matrices and prove that under certain conditions on network parameters, a bilaterally stable network is unique.

Data Backup Network Formation with Heterogeneous Agents

Social storage systems are a good alternative to existing data backup systems of local, centralized, and P2P backup. In this paper, we look at two untouched aspects of social storage systems. One aspect involves modelling social storage as an endogenous social network, where agents themselves decide with whom they want to build data backup relation. The second aspect involves studying the stability of social storage systems, which would help reduce maintenance costs and further, help build efficient as well as contented networks. 
We have a four fold contribution that covers the above two aspects. We, first, model the social storage system as a strategic network formation game. We define the utility of each agent in the network under two different frameworks. Second, we propose the concept of bilateral stability which refines the pairwise stability concept defined by Jackson et. al. 1996, by requiring mutual consent for both addition and deletion of links, as compared to mutual consent just for link addition. Mutual consent for link deletion is especially important in the social storage setting. Third, we prove necessary and the sufficient conditions for bilateral stability of social storage networks. For symmetric social storage networks, we prove that there exists a unique neighborhood size, independent of the number of agents (for all non-trivial cases), where no pair of agents has any incentive to increase or decrease their neighborhood size. We call this neighborhood size as the stability point. Fourth, given the number of agents and other parameters, we discuss which bilaterally stable networks would evolve and also discuss which of these stable networks are efficient --- that is, stable networks with maximum sum of utilities of all agents. We also discuss ways to build contented networks, where each agent achieves the maximum possible utility.

Stability, Efficiency, and Contentedness of Social Storage Networks

This paper investigates the impact of link formation between a pair of agents on the resource availability of other agents (that is, externalities) in a social cloud network, a special case of endogenous sharing economy networks. Specifically, we study how the closeness between agents and the network size affect externalities. 
We conjecture, and experimentally support, that for an agent to experience positive externalities, an increase in its closeness is necessary. The condition is not sufficient though. We, then, show that for populated ring networks, one or more agents experience positive externalities due to an increase in the closeness of agents. Further, the initial distance between agents forming a link has a direct bearing on the number of beneficiaries, and the number of beneficiaries is always less than that of non-beneficiaries.

Nagarajan Krishnamurthy

Papers

Externalities in endogenous sharing economy networks

Stationary, completely mixed and symmetric optimal and equilibrium strategies in stochastic games

Data Backup Network Formation with Heterogeneous Agents

Stability, Efficiency, and Contentedness of Social Storage Networks

Externalities in Endogenous Sharing Economy Networks.