Dynamic oligopoly pricing with reference-price effects

We analyze the strategic implications of consumers’ reference-price effects, either symmetric (for loss-neutral consumers) or asymmetric (for loss-averse consumers), in a differentiated oligopoly model where firms compete either in prices (à la Bertrand) or in quantities (à la Cournot) over an infinite time horizon. The dynamic game is specified in continuous time. The solution concept is Markov Perfect Equilibrium. We show how price dynamics in the presence of reference-price effects crucially depends on the nature of market competition. One of the main results of our analysis is that, with loss-averse consumers, there exists an interval of initial reference prices such that firms adopt the same constant-pricing strategy in both the Bertrand and the Cournot games, implying that the distinction between price and quantity competition has no impact on market conduct and performance.     

A Cournot–Nash–Bertrand game theory model of a service-oriented Internet with price and quality competition among network transport providers

This paper develops a game theory model of a service-oriented Internet in which profit-maximizing service providers provide substitutable (but not identical) services and compete with the quantities of services in a Cournot–Nash manner, whereas the network transport providers, which transport the services to the users at the demand markets, and are also profit-maximizers, compete with prices in Bertrand fashion and on quality. The consumers respond to the composition of service and network provision through the demand price functions, which are both quantity and quality dependent. We derive the governing equilibrium conditions of the integrated game and show that it satisfies a variational inequality problem. We then describe the underlying dynamics, and provide some qualitative properties, including stability analysis. The proposed algorithmic scheme tracks, in discrete-time, the dynamic evolution of the service volumes, quality levels, and the prices until an approximation of a stationary point (within the desired convergence tolerance) is achieved. Numerical examples demonstrate the modeling and computational framework.     

Global exponential stability of BAM neural networks with distributed delays and impulses

Convergence dynamics of bi-directional associative memory (BAM) neural networks with continuously distributed delays and impulses are discussed. Without assuming the differentiability and the monotonicity of the activation functions and symmetry of synaptic interconnection weights, sufficient conditions to guarantee the existence and global exponential stability of a unique equilibrium are given.     

On Cournot–Bertrand competition with differentiated products

In this paper, we present a game theoretic framework for Cournot–Bertrand competition based on a nonlinear price function. The competition is between two firms and is assumed to take place in terms of pricing decision and quantity produced. However, the proposed objective function has not been used in literature before, yet the throughput obtained in this paper generalizes some of the existing results in literature. The competitive interaction between firms is described and analyzed using best-reply reaction, proposed adaptive adjustment and bounded rationality approach. The condition of stability of Nash equilibrium (NE) is induced by these approaches. Interestingly, we prove that there exists exactly a unique NE. Furthermore, it is noticed that when firms adopt best-reply and the proposed adaptive adjustment, the firms’ strategic variables become asymptotically stable. On the contrary, when the bounded rationality is used both quantity and price behave chaotically due to bifurcation occurred.     

Almost periodic solutions for shunting inhibitory cellular neural networks without global Lipschitz activation functions

In this paper the shunting inhibitory cellular neural networks (SICNNs) with continuously distributed delays are considered. Without assuming the global Lipschitz conditions of activation functions, sufficient conditions for the existence and local exponential stability of the almost periodic solutions are established by using a fixed point theorem, Lyapunov functional method and differential inequality techniques. The results of this paper are new and they complement previously known results.     

Stability analysis of Cohen–Grossberg neural network with both time-varying and continuously distributed delays

In this paper, the Cohen–Grossberg neural network model with both time-varying and continuously distributed delays is considered. Without assuming both global Lipschitz conditions on these activation functions and the differentiability on these time-varying delays, applying the idea of vector Lyapunov function, M-matrix theory and inequality technique, several new sufficient conditions are obtained to ensure the existence, uniqueness, and global exponential stability of equilibrium point for Cohen–Grossberg neural network with both time-varying and continuously distributed delays. These results generalize and improve the earlier publications. Two numerical examples are given to show the effectiveness of the obtained results. It is believed that these results are significant and useful for the design and applications of the Cohen–Grossberg neural networks.     

Oligopoly and stability

In this paper, the so called Theocharis–Cournot problem is reconsidered. It concerns the relation between oligopoly and perfect competition, in particular the destabilization of Cournot equilibrium when the number of competitors increases. Using a CES production function where one input, capital, is fixed during periods of investment, a mixed short/long run market dynamics is set up. In the short run, with capital fixed, there is a capacity limit for production possibilities, whereas, at moments of capital renewal there are constant returns to scale. In this setting the local stability of Cournot equilibrium is reconsidered. It is demonstrated that if no more than two firms reinvest in the same time period, and the wage rate is not too high, then the Cournot equilibrium is stable.     

LMI conditions for stability of impulsive stochastic Cohen–Grossberg neural networks with mixed delays

In this paper, the global asymptotic stability of impulsive stochastic Cohen–Grossberg neural networks with mixed delays is investigated by using Lyapunov–Krasovskii functional method and the linear matrix inequality (LMI) technique. The mixed time delays comprise both the multiple time-varying and continuously distributed delays. Some new sufficient conditions are obtained to guarantee the global asymptotic stability of the addressed model in the stochastic sense using the powerful MATLAB LMI toolbox. The results extend and improve the earlier publications. Two numerical examples are given to illustrate the effectiveness of our results.     

Convergence dynamics of stochastic reaction–diffusion recurrent neural networks with continuously distributed delays

Convergence dynamics of reaction–diffusion recurrent neural networks (RNNs) with continuously distributed delays and stochastic influence are considered. Some sufficient conditions to guarantee the almost sure exponential stability, mean value exponential stability and mean square exponential stability of an equilibrium solution are obtained, respectively. Lyapunov functional method, M-matrix properties, some inequality technique and nonnegative semimartingale convergence theorem are used in our approach. These criteria ensuring the different exponential stability show that diffusion and delays are harmless, but random fluctuations are important, in the stochastic continuously distributed delayed reaction–diffusion RNNs with the structure satisfying the criteria. Two examples are also given to demonstrate our results.     

多寡头市场下领先者、追随者和竞争者的市场绩效比较分析

根据"结构-行为-绩效"的SCP分析框架,分析了企业在多寡头产量竞争的Cournot市场结构、多寡头价格竞争的Bertrand市场结构、1个领先者和多个追随者的Stackberg市场结构下,分别采取自主创新、跟踪新产品开发和引进模仿等不同的产品开发战略的市场绩效.结果表明,在同质产品多寡头市场上的产量竞争中,企业采取领先者、竞争者和追随者3种行为的企业均衡产量和企业利润依次递减;多寡头Stackberg市场结构在总产量、消费者剩余和社会福利上表现更佳;多寡头Cournot市场结构在市场价格和行业总利润上更高.在异质产品多寡头市场上的Bertrand价格竞争中,互补品市场的均衡价格和均衡产量相对于替代品都提高;当替代程度较大时,寡头数目较少,同时每个寡头的均衡产量和均衡价格都上升.     

Cournot vs. Bertrand under relative performance delegation: Implications of positive and negative network externalities

This paper demonstrates that relative-performance based strategic managerial delegation does not lead to the equivalence of Bertrand and Cournot equilibria in the presence of network externalities, regardless of the strength and type of network externalities — positive or negative. In the presence of positive network externalities, under relative-performance based delegation, Bertrand competition yields lower prices and profits, and higher quantities, consumers surplus and welfare than Cournot competition. On the contrary, these rankings are completely reversed in the presence of negative network externalities. It also discusses the endogenous choice of price or quantity contract under delegation in the presence of network externalities.     

Stochastic stability of Markovian jumping genetic regulatory networks with mixed time delays

In this paper, the stability analysis problem is investigated for a class of Markovian jumping genetic regulatory networks (GRNs) with mixed time delays (discrete time delays and distributed time delays) and stochastic perturbations. The main purpose of the addressed stability analysis problem is to establish some easy-to-verify conditions under which the dynamics of the true concentrations of the messenger ribonucleic acid and protein is asymptotically stable. By utilizing a more general Lyapunov-Krasovskii functional based on the idea of “delay decomposing” and the LMI (linear matrix inequality) technique, we derive sufficient delay-dependent conditions ensuring the asymptotically stability of the GRNs with mixed time delays and noise perturbations in terms of LMI. Finally, simulation examples are exploited to illustrate the effectiveness of the developed theoretical results.     

Almost periodic solutions of shunting inhibitory cellular neural networks on time scales

In this paper shunting inhibitory cellular neural networks (SICNNs) with time-varying and continuously distributed delays are considered on time scale T. Without assuming the global Lipschitz conditions of activation functions, some new sufficient conditions for the existence and asymptotic stability of the almost periodic solutions are established on time scales. Two numerical examples are given to illustrate our feasible results.     

The asymptotic behavior of dynamic producer-consumer systems

Dynamic Arrow-type price dynamics are investigated in a continuous time framework. The existence of a unique equilibrium is first proved under realistic conditions. Then, the local asymptotic stability of the equilibrium in the presence of instantaneous price and output information is shown. Continuously distributed time lags are then assumed in obtaining and implementing price and output information, or equivalently, it may be assumed that the firms and/or the market wants to react to long term effects rather than to follow sudden changes in price or outputs. If a time lag is assumed only in estimating the demand in the market, then the local asymptotic stability of the equilibrium is preserved. If the producers also use delayed information, then instability may occur. Stability conditions are derived and in the case of bifurcation the possibility of the birth of limit cycles is explored.     

Hopf bifurcation and stability crossing curves in a cobweb model with heterogeneous producers and time delays

We study a continuous time cobweb model with discrete time delays where heterogeneous producers behave as adapters in the market. Specifically, they partially adjust production (which is subject to some gestation lags) towards the profit-maximising quantity under static expectations. The dynamics of the economy is described by a two-dimensional system of delay differential equations. We characterise stability properties of the stationary state of the system and show the emergence of Hopf bifurcations. We also apply some recent mathematical techniques (stability crossing curves) to show how heterogeneous time delays affect the stability of the economy.     

具有不对称网络外部性和纵向差异化的产品竞争策略

在产品不完全覆盖市场中,研究具有不对称网络外部性的纵向差异化产品的Bertrand价格竞争或Cournot数量竞争策略.研究表明,两产品在Cournot数量竞争中的市场利润和社会福利都大于在Bertrand价格竞争中的市场利润和社会福利.在Bertrand价格竞争或Cournot数量竞争中,当低质量产品的网络外部性较大且满足一定条件时,低质量产品也可以获得较大的市场利润;当高质量产品具有较大网络外部性,或网络外部性虽然较小但满足一定条件条件,网络外部性相等或产品都不具有网络外部性时,高质量产品获得较大的市场利润.随着网络外部性的增强,Cournot-Nash均衡点并不稳定,在重复博弈以后,均衡点向Bertrand-Nash均衡点靠近.     

Stability results for stochastic delayed recurrent neural networks with discrete and distributed delays

We present new conditions for asymptotic stability and exponential stability of a class of stochastic recurrent neural networks with discrete and distributed time varying delays. Our approach is based on the method using fixed point theory, which do not resort to any Liapunov function or Liapunov functional. Our results neither require the boundedness, monotonicity and differentiability of the activation functions nor differentiability of the time varying delays. In particular, a class of neural networks without stochastic perturbations is also considered. Examples are given to illustrate our main results.     

New results of almost periodic solutions for recurrent neural networks

In this paper recurrent neural networks with time-varying delays and continuously distributed delays are considered. Without assuming the global Lipschitz conditions of activation functions, some sufficient conditions for the existence and local exponential stability of the almost periodic solutions are established, which are new and complement previously known results.     

Ex-post price stability with convex costs

Homogeneous goods markets with convex costs, do not generally possess Bertrand-Nash equilibria in pure strategies. In order to identify ex-post stable prices in such markets, the set of outcomes feasible in Bertrand competition are analysed as a non-transferable utility coalitional game. The market-clearing price is shown to always implement a strict-core outcome. Moreover, where at least two sellers compete, the strict-core converges to only admit market-clearing outcomes. The analysis has implications for a number of prominent models of oligopoly competition. When firms engage in capacity pre-commitment, the set of ex-post stable prices converges to the corresponding Cournot prices. This result holds for arbitrary capacity choices and a general class of rationing rules. Conversely, double-marginalisation is never ex-post stable.