Co-primary inter-operator spectrum sharing over a limited spectrum pool using repeated games

We consider two small cell operators deployed in the same geographical area, sharing spectrum resources from a common pool. A method is investigated to coordinate the utilization of the spectrum pool without monetary transactions and without revealing operator-specific information to other parties. For this, we construct a protocol based on asking and receiving spectrum usage favors by the operators, and keeping a book of the favors. A spectrum usage favor is exchanged between the operators if one is asking for a permission to use some of the resources from the pool on an exclusive basis, and the other is willing to accept that. As a result, the proposed method does not force an operator to take action. An operator with a high load may take spectrum usage favors from an operator that has few users to serve, and it is likely to return these favors in the future to show a cooperative spirit and maintain reciprocity. We formulate the interactions between the operators as a repeated game and determine rules to decide whether to ask or grant a favor at each stage game. We illustrate that under frequent network load variations, which are expected to be prominent in small cell deployments, both operators can attain higher user rates as compared to the case of no coordination of the resource utilization.Comment: To be published in proceedings of IEEE International Conference on Communications (ICC) at London, Jun. 201

Market Share Dynamics in a Model with Search and Word-of-Mouth Communication

This paper analyzes price competition in an infinitely repeated duopoly game. In each period, consumers remember the existence and location of their previous supplier. New information is gathered via search or word-of-mouth communication. Market outcomes are history-dependent, and the Markov perfection refinement is used to narrow the set of equilibria. Firms are shown to use mixed pricing strategies in equilibrium. The resulting price dispersion generates non-trivial market share dynamics. The goal of the paper is to characterize these dynamics, and to reveal the driving forces behind them

Payoff levels, loss avoidance, and equilibrium selection in the Stag Hunt: an experimental study

Game theorists typically assume that changing a game’s payoff levels—by adding the same constant to, or subtracting it from, all payoffs—should not affect behavior. While this invariance is an implication of the theory when payoffs mirror expected utilities, it is an empirical question when the “payoffs” are actually money amounts. In particular, if individuals treat monetary gains and losses differently, then payoff–level changes may matter when they result in positive payoffs becoming negative, or vice versa. We report the results of a human–subjects experiment designed to test for two types of loss avoidance: certain–loss avoidance (avoiding a strategy leading to a sure loss, in favor of an alternative that might lead to a gain) and possible–loss avoidance (avoiding a strategy leading to a possible loss, in favor of an alternative that leads to a sure gain). Subjects in the experiment play three versions of Stag Hunt, which are identical up to the level of payoffs, under a variety of treatments. We find differences in behavior across the three versions of Stag Hunt; these differences are hard to detect in the first round of play, but grow over time. When significant, the differences we find are in the direction predicted by certain– and possible–loss avoidance. Our results carry implications for games with multiple equilibria, and for theories that attempt to select among equilibria in such games

Quantum Probabilities as Behavioral Probabilities

We demonstrate that behavioral probabilities of human decision makers share many common features with quantum probabilities. This does not imply that humans are some quantum objects, but just shows that the mathematics of quantum theory is applicable to the description of human decision making. The applicability of quantum rules for describing decision making is connected with the nontrivial process of making decisions in the case of composite prospects under uncertainty. Such a process involves deliberations of a decision maker when making a choice. In addition to the evaluation of the utilities of considered prospects, real decision makers also appreciate their respective attractiveness. Therefore, human choice is not based solely on the utility of prospects, but includes the necessity of resolving the utility-attraction duality. In order to justify that human consciousness really functions similarly to the rules of quantum theory, we develop an approach defining human behavioral probabilities as the probabilities determined by quantum rules. We show that quantum behavioral probabilities of humans not merely explain qualitatively how human decisions are made, but they predict quantitative values of the behavioral probabilities. Analyzing a large set of empirical data, we find good quantitative agreement between theoretical predictions and observed experimental data.Comment: Latex file, 32 page

Online Learning in Case of Unbounded Losses Using the Follow Perturbed Leader Algorithm

In this paper the sequential prediction problem with expert advice is considered for the case where losses of experts suffered at each step cannot be bounded in advance. We present some modification of Kalai and Vempala algorithm of following the perturbed leader where weights depend on past losses of the experts. New notions of a volume and a scaled fluctuation of a game are introduced. We present a probabilistic algorithm protected from unrestrictedly large one-step losses. This algorithm has the optimal performance in the case when the scaled fluctuations of one-step losses of experts of the pool tend to zero.Comment: 31 pages, 3 figure

The Role of area-yield crop insurance program face to the Mid-term Review of Common Agricultural Policy

The mid-term review of Common Agricultural Policy increases the complexity of the decision-making process of farmers. The subsidies are substituted for a single decoupled income payment. The farmers decide what crops and livestock will produce based on climate, soils conditions and agricultural market signals and not based on subsidies granted to each one of the crop and livestock activities. The area-yield crop insurance program might have an important role on increasing production and facing natural catastrophes. This paper studies the introduction of the area-yield crop insurance program to reduce the risk originating from the variability of farmers' income and to compare this alternative with other agricultural policy alternatives in the context of the mid-term review of Common Agricultural Policy. The comparison of the introduction of the area-yield crop insurance program with other agricultural policy alternatives is made through an approach using concepts of the Cumulative Prospect Theory, because besides defining that the results are appraised in agreement with changes in relation to the initial wealth, this theory treats in a differentiated way gains and losses. A discrete sequential stochastic programming model with five states of nature is developed to study agricultural policy alternatives. The objective function is constituted by a set of functions (the value function and the probability weighting function) differentiated for gains and losses, in that the total value of the game is given by the sum of the positive and negative components. The value functions and the weighting probabilities are elicited by the Trade-off and Certainty Equivalent methods for a group of farmers in the Alentejo dryland region of Portugal. The set of constraint restrictions describes the environment in which the Alentejo farmers develop their crop and livestock activities in all their components: production, financial, marketing and taxes. Model results show the introduction of the area-yield crop insurance program with full decoupling of income payments from agricultural production under the mid-term review of the Common Agricultural Policy has positive effects in the agricultural production. This new Agricultural Policy guarantees a minimum farm income, while the area-yield crop insurance program allows making face to the agricultural production variability and avoids the abandonment of the farming activity in the Alentejo dryland region.Cumulative Propospect Theory, Mid-Term Review of the Common Agricultural Policy, Discrete Sequential Stochastic Programming Model, Area-Yield Crop Insurance program, Risk and Uncertainty,