Abstract
The conclusions of the Bertrand model of competition are substantially altered by the presence of either differentiated goods or asymmetric information about rival's production costs. In this paper, we consider a Bertrand competition, with differentiated goods. Furthermore, we suppose that each firm has two different technologies, and uses one of them according to a certain probability distribution. The use of either one or the other technology affects the unitary production cost. We show that this game has exactly one Bayesian Nash equilibrium. We do ex-ante and ex-post analyses of firms' profits and market prices. We prove that the expected profit of each firm increases with the variance of its production costs. We also show that the expected price of each good increases with both expected production costs, being the effect of the expected production costs of the rival dominated by the effect of the own expected production costs.

Abstract
We describe three different but related scenarios for determination of asset prices in an incomplete market: one scenario uses a market game approach whereas the other two are based on risk sharing or regret minimizing considerations.

Abstract
This paper develops a theoretical framework to study spatial price competition in a Hotelling-type network game. Each firm i is represented by a node of degree k(i), where k(i) is the number of firm i 's direct competitors (neighbors). We investigate price competition a la Hotelling with complete and incomplete information about the network structure. The goal is to investigate the effects of the network structure and of the uncertainty on firms' prices and profits. We first analyze the benchmark case where each firm knows its own degree as well as the rivals' degree. Then, in order to understand the role of information in the price competition network, we also analyze the incomplete information case where each firm knows its type (i.e. number of connections) but not the competitors' type.

Abstract
We introduce the yes-no decision model, where individuals can make the decision yes or no. We characterize the coherent and uncoherent strategies that are Nash equilibria. Each decision tiling indicates the way coherent and uncoherent Nash equilibria co-exist and change with the relative decision preferences of the individuals for the yes or no decision. There are 289 combinatorial classes of decision tilings, described by the decision bussola, which demonstrates the high complexity of making decision.

Abstract
We present a model of an Edgeworthian exchange economy where two goods are traded in a market place. For a specific class of random matching Edgeworthian economies, the expectation of the limiting equilibrium price coincides with that of related Walrasian economies. The novelty of our model is that we assign a bargaining skill factor to each participant which introduces a game, similar to the prisoner's dilemma, into the usual Edgeworth exchange economy. We analyze the effect of the bargaining skill factor on the amount of goods acquired and the overall increase in the utility of the consumer. Finally, we let the bargaining skills of the participants evolve with subsequent trades and study the impact of this change over time.

Abstract
Ourmain interest is to study the relevant biological thresholds that appear in epidemic and immunological dynamical models. We compute the thresholds of the SIRI epidemic models that determine the appearance of an epidemic disease. We compute the thresholds of a Tregs immunological model that determine the appearance of an immune response.