International Environmental Agreement: a Dynamic Model of Emissions Reduction

We model an International Environmental Agreement as a two stages game: during the first stage each country decides whether or not to join the agreement while, in the second stage, the quantity of emissions reduction is choosen. Players determine their abatement levels in a dynamic setting, given the dynamics of pollution stock and the strategies of other countries. Players may act cooperatively, building coalitions and acting according to the interest of the coalition, or they make their choices taking care of their individual interest only. Countries can behave myopically or in a farsighted way. As a consequence, the size of stable coalition can completely change. A continuous time framework is choosen in the present paper and consequently the problem is studied by a differential game.IEA, Differential games, Coalition stability.

Farsighted Stable Sets

A coalition is usually called stable if nobody has an immediate incentive to leave or to enter the coalition since he does not improve his payoff. This myopic behaviour does not consider further deviations which can take place after the first move. Chwe (1994) incorporated the idea of a farsighted behaviour in his definition of large consistent set (LCS). In some respects, we propose a different idea of dominance relation based on indirect dominance and on a different concept of belief on moving coalitions' behavior. A notion of stability for a coalitional game is introduced by taking into account the different degree of risk/safety of any player participating in a move. Some results about uncovered sets, internal stability are investigated. By exploiting our dominance and stability concepts, the prisoner's dilemma in coalitional form and its Nash equilibrium are studied. Some examples illustrating the differences between the largest consistent set, our stable set and stable set due to von Neumann and Morgenstern (1947) are presented.

Design Imitation in the Fashion Industry

The paper deals with the imitation of fashion products, an issue that attracts considerable interest in practice. Copying of fashion originals is a major concern of designers and, in particular, their financial backers. Fashion firms are having a hard time fighting imitations, but legal sanctions are not easily implemented in this industry. We study an alternative strategy that has been used by designers. Instead of fighting the imitators in the courtroom, designers fight them in the market. The designer markets her products in separate markets, typically a high class market in which the products are sold in exclusive stores at high prices. Customers in this market seek exclusivity and their utility diminishes when seeing an increasing number of copies around. Their perception of the brand tend to dilute which poses a serious threat to a fashion company. The second market is a middle class market in which there are many more buyers, and the fashion firm competes directly with the imitators in this market. This market can be used to practise price discrimination, to sell off left-over inventories, and to get a spin-off from the design. The paper models the decision problems of the fashion firm and the imitators as a two-period game in which firms make pricing decisions and decisions on when to introduce their products in the markets. In addition, the fashion firm decides how much efforts to spend to increase its brand image in the two markets.

Optimal Control Problems Arising In Marketing Models

The diffusion in time of a new product in a monopolistic or oligopolistic market can be described by a system of evolution equations (PDE, ODE, DDE) containing one or more control parameters (advertising, prices, plant locations, ...). The productors choose the control parameters in order to maximize their (discounted) prots. Hence an optimal control problems (in the case of a monopoly) or a dynamic game (in the case of an oligopoly) has to be solved. A specic model is proposed and an exhaustive description of its solution is given.

Optimal marketing decision in a duopoly: a stochastic approach

Let us consider two new perfect substitute durable products which are produced and sold in a market by two competing firms. Looking at a potential buyer, we build a stochastic rule by which she purchases the good from one of the two firms (so that she becomes an adopter). The model is considered discrete in time and space. The probability of transition from the non adopter state to the adopter one depends on an imitation mechanism (word-ofmouth) as well as on the pricing and advertising policies of the producers/sellers. It is assumed that only actual information about the market determine the evolution in the subsequent time step so that a Markov process arises. Both firms maximize their expected discounted profits by choosing optimal marketing strategies. Suitable equilibria are characterized and, because of the lack of convexity in the model, the simulated annealing algorithm is proposed to compute them.

Cooperazione e competizione nello sfruttamento di una risorsa rinnovabile

In this paper we propose a static model describing the commercial exploitation of a common property renewable resource by a population of agents. Players can cooperate or compete; cooperators maximize the utility of their group while defectors maximize their own profit. Agents aren't assumed to be divided into the two groups from the beginning; by solving the static game we obtained the best response function of i-th player without making other agents positions. Then, the Nash equilibria we calculated point out how different strategies - all the players cooperate, all the players compete or players can be divided into cooperators and defectors - can coexist.Resource Exploitation, Game theory

Yardstick competition and fiscal disparities: an experimental study

Recent theoretical research suggest that yardstick competition may be biased by the presence of fiscal disparities between local governments and that fiscal equalization may help in correcting this bias. This paper provides an empirical test of these theoretical predictions by means of a laboratory experiment

Yardstick competition and fiscal disparities: an experimental study

Recent theoretical research suggest that yardstick competition may be biased by the presence of fiscal disparities between local governments and that fiscal equalization may help in correcting this bias. This paper provides an empirical test of these theoretical predictions by means of a laboratory experiment

Effects of surface topography on growth and osteogenic differentiation of human mesenchymal stem cells

The clinical success of an endosseous artificial implant is related to the quality of its osseointegration with the surrounding living bone. To achieve a stable anchorage, mesenchymal cells, migrating to the implant surface from the surrounding tissue, must differentiate towards mature osteoblasts rather than connective tissue cell types. It is well known that the cell response is affected by the physicochemical parameters of the biomaterial surface, such as surface energy, surface charges or chemical composition. Topography seems to be one of the most crucial physical cues for cells (1). In particular, interactions between mesenchymal stem cells (MSCs) and surfaces with specific micro and nano patterns can stimulate MSCs to produce bone mineral in vitro (2). Herein, stamps reporting different micro and nano features were fabricated in order to obtain several corresponding replicas in a short time through microinjec- tion molding. Then, the effects of the substrate topography on human bone marrowderived MSC adhesion, proliferation, and osteogenic differentiation were investigated in the absence of inductive growth factors. Collectively, our data show that both micro- and nano-structured surfaces possess osteoinductive properties. A relationship between dimensional feature of surface topography and differentiative potential was noted. On the contrary, cell adhesion and proliferation seemed to be unaffected. Further in vivo studies will be carried out to confirm the osteoinductive properties of selected surface geometries

Umbilical cord mesenchymal stem cells modulate dextran sulphate sodium induced acute colitis in immunodeficient mice.

Inflammatory bowel diseases (IBD) are complex multi-factorial diseases with increasing incidence worldwide but their treatment is far from satisfactory. Unconventional strategies have consequently been investigated, proposing the use of stem cells as an effective alternative approach to IBD. In the present study we examined the protective potential of exogenously administered human umbilical cord derived mesenchymal stem cells (UCMSCs) against Dextran Sulphate Sodium (DSS) induced acute colitis in immunodeficient NOD.CB17-Prkdc scid/J mice with particular attention to endoplasmic reticulum (ER) stress. METHODS: UCMSCs were injected in NOD.CB17-Prkdc scid/J via the tail vein at day 1 and 4 after DSS administration. To verify attenuation of DSS induced damage by UCMSCs, Disease Activity Index (DAI) and body weight changes was monitored daily. Moreover, colon length, histological changes, myeloperoxidase and catalase activities, metalloproteinase (MMP) 2 and 9 expression and endoplasmic reticulum (ER) stress related proteins were evaluated on day 7. RESULTS: UCMSCs administration to immunodeficient NOD.CB17-Prkdc scid/J mice after DSS damage significantly reduced DAI (1.45\u2009\ub1\u20090.16 vs 2.08\u2009\ub1\u20090.18, p\u20093-fold), which were significantly reduced in mice receiving UCMSCs. Moreover, positive modulation in ER stress related proteins was observed after UCMSC administration. CONCLUSIONS: Our results demonstrated that UCMSCs are able to prevent DSS-induced colitis in immunodeficient mice. Using these mice we demonstrated that our UCMSCs have a direct preventive effect other than the T-cell immunomodulatory properties which are already known. Moreover we demonstrated a key function of MMPs and ER stress in the establishment of colitis suggesting them to be potential therapeutic targets in IBD treatment