A contract-based model for directed network formation

We consider a network game where the nodes of the network wish to form a graph to route traffic between themselves. We present a model where costs are incurred for routing traffic, as well as for a lack of network connectivity. We focus on directed links and the link stability equilibrium concept, and characterize connected link stable equilibria. The structure of connected link stable networks is analyzed for several special cases.     

A contest model of liberalizing government procurements

This paper models liberalization of government procurements as admitting entry of foreign firms in a contest among potential rent seekers. It contributes to the literature on how institutions influence socially desirable outcomes. Liberalizing procurements reduces wasteful domestic lobbying but also increases the likelihood that a foreign firm will capture the rent. A main result is that the domestic welfare change is not monotonic in the foreign firms' abilities. Furthermore, we show that domestic liberalization policies can be inefficient from the global point of view because foreign lobbying costs can outweight productive efficiency.     

A model of signed network formation with heterogeneous players

This paper proposes a model of formation of signed networks that comprise both positive (friendly/cooperative) and negative (antagonistic) social ties between players who differ intrinsically in strength. Friendships/alliances serve to increase one’s power over their intrinsic strength; in the determination of power it matters not how many allies one has, but who these allies are. The model proposed here is suited to any context where players derive power from friendships/alliances with stronger players and payoffs are extracted from less powerful enemies. The structure of ties across various types of players is studied in Nash equilibria along with a characterization of Nash equilibria under various parametric conditions.     

A note on network formation with decay

This paper studies an endogenous network formation with decay. We introduce a strategic form game based on a simple bilateral cost allocation rule. We show that a strong Nash equilibrium of this game always exists and necessarily achieves efficient networks.     

Farsighted network formation

This paper studies a model of dynamic network formation when individuals are farsighted: players evaluate the desirability of a “current” move in terms of its consequences on the entire discounted stream of payoffs. We define a concept of equilibrium which takes into account farsighted behavior of agents and allows for limited cooperation amongst agents. We show that an equilibrium process of network formation exists. We also show that there are valuation structures in which no equilibrium strategy profile can sustain efficient networks. We then provide sufficient conditions under which the equilibrium process will yield efficient outcomes.     

A game-theoretic model of coalition formation among primates

This paper models the coalition formation process among primates as a sequential game. The population consists of individuals having distinct social ranks which is determined by the individual’s resource holding potential. Each member of the population is interested in gaining access to a food resource, either individually or via a coalition. At any given stage of the game, a player can either propose a specific coalition or he can be proposed to in order to join one. Hence, the strategy of a player consists of a sequence of decisions regarding who to propose to for the formation of a coalition and which proposals to accept or reject. We derive the preferences of the players over the various coalition structures under the assumption that the probability of a coalition to obtain the resource is given by a logistic distribution as a function of relative strengths of the players. We show that, given the primates’ strategic behavior, a variety of different coalition structures can emerge in equilibrium.      

Knowledge integration and network formation

In this paper, we highlight how inter-firm collaboration networks are influenced by the knowledge composition of goods in an industry. For this purpose, we carry out an agent-based simulation study in which firms integrate their competencies under different knowledge-based regimes. In this way networks form. The results reveal that knowledge regime significantly influences the network structure, and interaction among firms not only is very intensive when the products are specialized but also have common knowledge among them.     

Group representation concerns and network formation

This paper studies processes of integration and segregation using a connections model in which individuals form valuable links that also entail a cost. Individuals belong to two different groups and care about whether their own group represents a sufficient fraction in their neighborhood. Concerns for representation promote the segregation of societies as even for small linking costs individuals do not link to different others because of the threat that their group becomes under-represented. For certain cost ranges, concerns for representation also determine efficient networks because forming links with members of the opposite group entails a utility loss due to under-representation.     

Nonprofits and public good provision: A contest based on compromises

Two competing nonprofits with ideologically distinct missions compete for donor funding to provide an indivisible public good in a population with heterogeneous preferences. This paper examines the extent to which (average) public values are undermined and nonprofits’ ideology compromised in a contractual game in which the right to provide the public good is the outcome of competition between nonprofits. We also scrutinize the roles of (i) cooperative versus competitive contracting, (ii) multiple public goods, (iii) enforceability of actions and (iv) observability of nonprofit costs in determining the equilibrium terms of the contract. In each case, the intensity of the ideological divide between the donor and the nonprofits jointly impact the degree to which compromises are made in terms of both the public's and nonprofit's missions, and the ability on the part of the donor to reap double (cost-saving and strategic) financial gains.     

A neural network based dynamic forecasting model for Trend Impact Analysis

Trend Impact Analysis is a simple forecasting approach, yet powerful, within the Futures Studies paradigm. It utilizes experts' judgements to explicitly deal with unprecedented future events with varying degrees of severity in generating different possibilities (scenarios) of how the future might unfold. This is achieved by modifying a surprise-free forecast according to events' occurrences based on a Monte-Carlo simulation process. Yet, the current forecasting mechanism of TIA is static. This paper introduces a new approach for constructing TIA by using a dynamic forecasting model based on neural networks. This new approach is designed to enhance the TIA prediction process. It is expected that such a dynamic mechanism will produce more robust and reliable forecasts. Its idea is novel, beyond state of the art and its implementation is the main contribution of this paper.     

Farsighted strategies in the formation of a communication network

I examine the formation of a specific communication network, a variant of the two-way flow model, in which agents have farsighted strategies. I show that the likelihood to form efficient networks tends to zero for sufficiently large network sizes.     

Strategic network formation through peering and service agreements

We introduce a game theoretic model of network formation in an effort to understand the complex system of business relationships between various Internet entities (e.g., Autonomous Systems, enterprise networks, residential customers). In our model we are given a network topology of nodes and links where the nodes act as the players of the game, and links represent potential contracts. Nodes wish to satisfy their demands, which earn potential revenues, but may have to pay their neighbors for links incident to them. We incorporate some of the qualities of Internet business relationships, including customer–provider and peering contracts. We show that every Nash equilibrium can be represented by a circulation flow of utility with certain constraints. This allows us to prove bounds on the prices of anarchy and stability. We also focus on the quality of equilibria achievable through centralized incentives.     

Signaling in social network and social capital formation

This paper presents a model of social capital and social network formation. The key interaction within the model is that whom an individual chooses to become friends with affects the value (social capital) of the friendship. In the model, how a player searches for and then forms friendships reveals how willing she is to engage in cooperation with a potential friend. Individuals observe their local network structure (friends and cliques) and the actions of players within these. Willingness to cooperate is private information and is captured by the discount factor of an individual. Cooperative types have high discount factors and can signal their type by forming a clique through befriending a friend of a friend. Uncooperative types do not form these kinds of friendships because of the local observability of their actions to all members of a clique. Thus, when a player meets someone with whom she shares a friend, her belief that the individual has a high discount factor is greater than the population average. In this sense, people “trust” each other more when they share a friend in common. Finally, I relate the primitives of the model to characteristics of the implied social network by nesting the sequential equilibrium in an algorithm of network formation proposed by Jackson and Rogers (Am Econ Rev 97(3):890–915, 2007). The model highlights a trade-off between maximizing the total amount of social capital in a society and distributing it equitably across individuals.     

Estimating noncooperative and cooperative models of bargaining: an empirical comparison

This paper examines the issue of model selection in studies of strategic situations. In particular, we compare estimation results from a noncooperative formulation of government formulation à la (Baron and Ferejohn in Am Poli Sci Rev 87:34–47, 1989) with those from two alternative cooperative formulations (Nash in Econometrica 18:155–162, 1950; Shapley and Shubik in Am Poli Sci Rev 48:787–792, 1954). Although the estimates of the ministerial ranking are similar, statistical testing suggests that the noncooperative formulation is best fitted to the observed data among the alternative models. This result implies that modeling the noncooperative structure in bargaining situations is crucially important at the risk of possibly misspecifying the details of the game.     

Collusive behavior in noncooperative epsilon-equilibria of oligopolies with long but finite lives

In a game of a finite number of repetitions of a Cournot-type model of an industry, if firms are satisfied to get close to (but not necessarily achieve) their optimal responses to other firms' sequential strategies, then in the resulting noncooperative “equilibria” of the sequential market game, (1) if the lifetime of the industry is large compared to the number of firms, there are equilibria corresponding to any given duration of the cartel, whereas (2) if the number of firms is large compared to the industry's lifetime, all equilibria will be close (in some sense) to the competitive equilibrium.     

Walrasian equilibria as limits of noncooperative equilibria. Part II: Pure strategies

We examine the connection between Walrasian equilibria of a limit economy (with infinitesimal firms) and noncooperative (Cournot) equilibria of approximating finite economies (with significant firms). Nonconvex production sets, decreasing returns in the aggregate, and endogenous determination of the number of active firms are allowed. A Walrasian equilibrium is a limit of pure strategy noncooperative equilibria only if a condition (loosely analogous to downward sloping demand in the partial equilibrium constant returns to scale case) holds. The condition is also sufficient to guarantee the existence of a robust sequence of pure strategy noncooperative equilibria which converges to the Walrasian equilibrium.     

开放式创新社区网络的系统动力学模型

环境的变迁要求企业积极变革创新模式,寻求更多的创新方法。在分析开放式创新社区网络的系统特性和结构特点的基础上,从知识转移与流动、人力资本流动和创新收入增长3个方面整合了开放式创新社区网络的系统动力学模型,分析了开放式创新社区网络在运行过程中的3个关键因素,即系统内部整合、创新收入增长方式的多样化和开放式创新文化建设,并为企业有效管理和利用开放式创新平台来提高创新绩效、提升企业创新能力、实现企业价值增长,提出政策建议。