Essays on the Economics of Networks

Essays on the Economics of Networks
Author: Alexander Graupner
Publisher:
Total Pages: 110
Release: 2020
Genre:
ISBN:

This dissertation contains three chapters on how economic networks affect various market situations. Broadly, they cover contracting and monopoly pricing in the presence of economic networks. The first chapter considers a principal, many agents contracting problem. Agents sit on a network of complementarities. That is, the effort of one agent affects the value of effort for those with whom he connects. Given this structure on effort, I characterize the first best contract. This contract induces efforts that reflect the agents Bonacich centrality in the symmetrized network. I then consider a variety of bilateral contracts, and compare their values for the principal. First, I consider bilateral forcing contracts. These contracts induce less effort per agent than the first best contract. Agents' effort distortions depends on their bibliographic coupling. I show that it is this novel measure that drives effort down for certain agents. Networks with high total bibliographic coupling have a large profit gap from first to second best forcing contracts. I compare these contracts to bilateral linear contracts, and show that linear contracts outperform the forcing contracts. Finally, I show that base and bonus contracts are profit maximizing for the principal, and implement first best. The second chapter considers a monopolist who introduces a new durable good to a base of consumers who are connected on a network of communication. Consumers are initially unaware of the product, and must learn about its existence through their neighbors. Each consumer who purchases informs a group of neighbors, and the information flows through consumers as a branching process. The monopolist commits to a dynamic price path on the infinite horizon. I find that though consumers are fully strategic, the monopolist finds it optimal to serve the entire consumer base infinitely often, which implies a sales structure. I then derive the optimal price path for a simplified model of two agents, and derive comparative statics. The third chapter considers a monopolist who sells to a consumer base that is largely unaware of the product. The monopolist spreads the information of the product to consumers by the past purchasers. I assume that the monopolist knows the exact network structure on which consumers live, and sets prices based off of consumers positions and the aware set of consumers. I consider three different pricing strategies. First, I consider a setting where the monopolist can price discriminate based on the consumers' network position. In this case I am able to find which consumers are important to the information flow. Consumers who are aware early get a discount, along with agents who are critical to the information flow. If there are consumers who can only be reached through one consumer purchasing, this consumer is offered a discounted price. I see that these ideas follow through to the single priced monopolist case, where prices fluctuate if many critical agents exist. Finally, I consider the optimal mechanism, where the monopolist can price discriminate based off of network position and price. In this case the monopolist can find the optimal flow of information and implement it.

Essays on Economics of Networks

Essays on Economics of Networks
Author: Soomin Jung
Publisher:
Total Pages:
Release: 2021
Genre:
ISBN:

This dissertation is on economics of networks. The first two chapters study what network sellers and buyers create when there exist gains of trade. The last chapter studies information diffusion on a given network. In the first two chapters, I study sellers and buyers who trade via bargaining. Agents can often increase their bargaining power by increasing the value of their outside options. They may seek to invest in costly relationships with potential trade partners. That is, they form an endogenous trade network and then bargain with their trade partners. I study a two-stage model in which sellers and buyers trade non-cooperatively on an endogenous trade network. In Chapter 1, sellers are assumed to have no capacity constraints. The main result of this chapter is that even though agents can increase their bargaining power by forming relationships with multiple trading partners, there exists an efficient subgame perfect equilibrium--that is, all the gains from trade are realized with the minimum costs and without a delay. Chapter 2 assumes that sellers are endowed with one unit of a good for a trade following the tradition of the bargaining literature. The capacity constraint increases the seller's bargaining power if there are many buyers who want to buy a good from each seller. This may give incentives to sellers to invest in superfluous links. Chapter 2 shows that the market can achieve efficiency even if sellers have the capacity constraint. In specific, a bilateral trading network is supported as an equilibrium network. Chapter 3 studies information diffusion on a fixed network through word-of-mouth. Word-of-mouth is an effective tool that a firm leverages to advertise the quality of its products to uninformed consumers. Such viral marketing, however, may fail if the consumers' "words" are not credible. Suppose that consumers are located on a given network and a firm "buys" one consumer and employs her as an implant to make recommendations of a product to her neighbors regardless of the actual quality of the good. I show that the viral marketing fails if the consumer network has a node with an excessively high degree of connection--for instance, a star network or a complete network--which undermines the credibility of the recommendation from an implant employed by a firm to promote a bad quality product. Also, if the viral marketing works, a good quality product is spread out over the network while a bad quality is driven out.

Three Essays on Networks and Public Economics

Three Essays on Networks and Public Economics
Author: Pier-André Bouchard St Amant
Publisher:
Total Pages: 336
Release: 2013
Genre:
ISBN:

This thesis is a collection of three essays. The first two study how ideas spread through a network of individuals, and how it an advertiser can exploit it. In the model I develop, users choose their sources of information based on the perceived usefulness of their sources of information. This contrasts with previous literature where there is no choice made by network users and thus, the information flow is fixed. I provide a complete theoretical characterization of the solution and define a natural measure of influence based on choices of users. I also present an algorithm to solve the model in polynomial time on any network, regardless of the scale or the topology. I also discuss the properties of a network technology from a public economic standpoint. In essence, a network allows the reproduction of ideas for free for the advertiser. If there is any free-riding problem, I show that coalitions of users on the network can solve such problem. I also discuss the social value of networks, a value that cannot be captured for profit. The third essay is completely distinct from the network paradigm and instead studies funding rules for public universities. I show that a funding rule that depends solely on enrolment leads to "competition by franchise" and that such behavior is sometimes inefficient. I suggest instead an alternate funding rule that allows government to increase welfare without increasing spending in universities.

Essays on Social Networks in Development Economics

Essays on Social Networks in Development Economics
Author: Arun Gautham Chandrasekhar
Publisher:
Total Pages: 210
Release: 2012
Genre:
ISBN:

(cont.) substitutes for commitment. On net, savings allows individuals to smooth risk that cannot be shared interpersonally, with the largest benefits for those who are weakly connected in the network. The final chapter (co-authored with my classmates Horacio Larreguy and Juan Pablo Xandri) attempts to determine which models of social learning on networks best describe empirical behavior. Theory has focused on two leading models of social learning on networks: Bayesian and DeGroot rules of thumb learning. These models can yield greatly divergent behavior; individuals employing rules of thumb often double-count information and may not exhibit convergent behavior in the long run. By conducting a unique lab experiment in rural Karnataka, India, set up to exactly differentiate between these two models, we test which model best describes social learning processes on networks. We study experiments in which seven individuals are placed into a network, each with full knowledge of its structure. The participants attempt to learn the underlying (binary) state of the world. Individuals receive independent, identically distributed signals about the state in the first period only; thereafter, individuals make guesses about the underlying state of the world and these guesses are transmitted to their neighbors at the beginning of the following round. We consider various environments including incomplete information Bayesian models and provide evidence that individuals are best described by DeGroot models wherein they either take simple majority of opinions in their neighborhood.

Essays on Social and Economic Networks

Essays on Social and Economic Networks
Author: Timo Hiller
Publisher:
Total Pages: 67
Release: 2011
Genre: Business networks
ISBN:

This thesis consists of three papers in the field of social and economic networks. In the first, called Peer Effects in Endogenous Networks, I build a model of endogenous net- work formation in the presence of peer effects, which play an important role for decisions concerning educational attainment, criminal activity, labor market participation and R&D expenditures of firms. The class of payoff functions assumed induce local complementar- ities in effort levels and positive local externalities. Links are one-sided and agents move simultaneously in links and effort levels. I find that equilibrium networks display - other than the complete and the empty network - a core-periphery structure, which is commonly observed in empirical studies. Ex-ante homogenous agents may obtain very different ex-post outcomes, depending on the network that arises in equilibrium. Multiplicity of equilibria serves as an explanation for large differences in behaviour across otherwise identical groups. The second paper, titled Alliance Formation and Coercion in Networks, presents a game-theoretic model of network formation, which allows agents to enter bilateral alliances and to extract payoffs from enemies. Each pair of agents creates a surplus of one, which allies divide in equal parts. If agents are enemies, then the agent with more allies obtains a larger share of the surplus. I show that Nash equilibria are of two types. First, a state of utopia, where all agents are allies. Second, asymmetric equilibria, such that agents can be partitioned into sets of different size, where agents within the same set are allies and agents in different sets are enemies. These results stand in contrast to coalition formation games in the economics of conflict literature, where stable group structures are generally symmetric. The model also provides a game-theoretic foundation for structural balance, a long-standing notion in social psychology, which has been fruitfully applied to the study of alliance formation in international relations. The third paper, A Note on Stochastically Stable States for Alliance Formation and Coercion in Networks, introduces dynamics into the model of the second paper and provides a conjecture for stochastically stable states. At every time period t and with fixed probability p, each agent adjusts his strategy myopically, while with small probability E chooses his strategy at random. The configuration where all agents sustain only positive links is shown to not be stochastically stable. Stochastically stable state are thought to be such that the number of cliques is maximal, under a restriction on the relative size of groups.

Organization with Incomplete Information

Organization with Incomplete Information
Author: Mukul Majumdar
Publisher: Cambridge University Press
Total Pages: 372
Release: 1998-09-13
Genre: Business & Economics
ISBN: 9780521553001

There have been systematic attempts over the last twenty-five years to explore the implications of decision making with incomplete information and to model an 'economic man' as an information-processing organism. These efforts are associated with the work of Roy Radner, who joins other analysts in this collection to offer accessible overviews of the existing literature on topics such as Walrasian equilibrium with incomplete markets, rational expectations equilibrium, learning, Markovian games, dynamic game-theoretic models of organization, and experimental work on mechanism selection. Some essays also take up relatively new themes related to bounded rationality, complexity of decisions, and economic survival. The collection overall introduces models that add to the toolbox of economists, expand the boundaries of economic analysis, and enrich our understanding of the inefficiencies and complexities of organizational design in the presence of uncertainty.