Extended OLIGOPOLY models will be introduced and examined in which the firms might face capacity limits, thresholds for minimal and maximal moves, and antitrust thresholds in the case of partial cooperation. Similar situation occurs when there is an additional cost of output adjustment, which is discontinuous at zero due to set-up costs. In these cases the payoff functions of the firms are nondifferentiable and in some cases even discontinuous. Under the usual concavity assumptions Cournot oligopolies have monotonic response functions and unique Cournot-Nash equilibrium. However the introduction of these more realistic additions into the OLIGOPOLY models creates a fundamentally new situation: the existence of no equilibrium or the presence of multiple, in some cases even infinitely many, equilibria. It also results in a very different asymptotic behavior of the dynamic extensions. The paper gives a brief survey of the relevant models, derives the response functions of the firms, and examines the existence and the number of equilibria. In the case of infinitely many equilibria the equilibrium-set will be also determined and characterized.

This paper provides a theoretical model in which the firms within a processing industry behave in an oligopolistic and oligopsonistic market simultaneously. The model developed yields an equation for profit margin influenced by determinants of marginal processing cost as well as distortions in both markets. By pooled cross section and time series data, the equation is estimated for eleven sugar factories involved in Tehran Exchange Market over the period of 1996-2003. Applications for both markets indicate that with an increase in both the input share and output share, it causes an increase in the profit margin; however, it reduces due to increasing in wages fuel and energy costs. With competitive oligopsonistic market, the collusion degree initiated by Clarke and Davies (1982) in oligoppolistic market is estimated. It turns out that the collusion parameter is lower and negligible since price elasticity of demand is a faction for the quasi price elasticity, but by considering only quasi price demand elasticity, the degree of collusion is estimated to be higher.

This paper discusses a problem in which n decentralized supply chains enter the market simultaneously with no existing rival chains, shape the supply chains’ networks, and set wholesale and retail prices in a noncooperative manner. All the chains produce either identical or highly substitutable products. Customer demand is elastic and price-dependent. A three-step algorithm is proposed to solve this problem. Step one considers the supply chains’ potential network structures. Step two is based on a finite-dimensional variational inequality formulation and is solved by a modified projection method to determine equilibrium prices. Step three selects the equilibrium locations to shape the chains’ equilibrium network structure with the help of the Wilson algorithm. Finally, this approach is applied to a real-world scenario, and the results are discussed. Moreover, sensitivity analyses are conducted.

Due to the status of Iranian pistachios in the world market and importance of the product in foreign exchange earnings, the study of the structure of the world market for taking more efficient measures and policies is essential. In this study, most of the importers of Iranian pistachio including the UAE, Germany and China considered. According to statistics, the role of America in the Emirates and Germany markets is trimmed and Iran has a monopoly. But in the Chinese market because the presence of America, there is an OLIGOPOLY. Therefore, in this study, demand in China market in the form of competitive Bertrand, Cournot and Stackelberg using a system of simultaneous equations was estimated. The recommendations were based on the results. Needed data were collected from FAO and World Bank. Finally some recommendations are made to strengthen Iranian situation in export market.

This paper presents the competitive supply chain network design problem in which n decentralized supply chainssimultaneously enter the market with no existing rival chain, shape their networks and set wholesale and retail prices incompetitive mode. The customer demand is elastic and price dependent, customer utility function is based on the Hotelingmodel and the chains produce identical or highly substitutable products. We construct a solution algorithm based onbi-level programming and possibility theory. In the proposed bi-level model, the inner part sets the prices based onsimultaneous extra-and Stackleberg intra-chains competitions, and the outer part shapes the networks in cooperativecompetitions. Finally, we use a real-word study to discuss the effect of the different structures of the competitors on theequilibrium solution. Moreover, sensitivity analyses are conducted and managerial insights are offered.

This paper presents a competitive supply chain network design problem in which one, two, or three supply chains are planning to enter the price-dependent markets simultaneously in uncertain environments and decide to set the prices and shape their networks. The chains produce competitive products either identical or highly substitutable. Fuzzy multi-level mixed integer programming is used to model the competition modes, and then the models are converted into an integrated bi-level one to be solved, in which the inner part sets the prices in dynamic competition and the outer part shapes the network cooperatively. Finally, a real-world problem is investigated to illustrate how the bi-level model works and discuss how price, market share, total income, and supply chain network behave with respect to key marketing activities such as advertising, promotions, and brand loyalty.

In this paper, the pricing and bandwidth allocation in heterogeneous wireless access networks is studied. Demand modeling and resource allocation in heterogeneous wireless access networks is carried out using the theories of microeconomics in competitive markets. A competitive market model for bandwidth allocation and pricing is presented where new relaxation models and propositions are developed to address various aspects of the operation of wirless access networks such as roaming and hand off control. We used the existing market theories to develop a solution for pricing of a unit of bandwidth of each network based on the marginal cost of the product. The client preferences with regard to available networks are also modeled in our network market model. On the other hand, network providers also adjust their product offering according to the market price. We prove that the user and bandwidth assignment made on the basis of this model where all agents have rational behavior is Pareto optimum that maximizes the utility of networks and clients.