ON PRICE TAKING BEHAVIOR IN A NONRENEWABLE RESOURCE CARTEL-FRINGE GAME

We consider a nonrenewable resource game with one cartel and a set of fringe members. We show that (i) the outcomes of the closed-loop and the open-loop nonrenewable resource game with the fringe members as price takers (the cartel-fringe game a la Salant 1976) coincide and (ii) when the number of fringe firms becomes arbitrarily large, the equilibrium outcome of the closed-loop Nash game does not coincide with the equilibrium outcome of the closed-loop cartel-fringe game. Thus, the outcome of the cartel-fringe open-loop equilibrium can be supported as an outcome of a subgame perfect equilibrium. However the interpretation of the cartel-fringe model, where from the outset the fringe is assumed to be price taker, as a limit case of an asymmetric oligopoly with the agents playing Nash-Cournot, does not extend to the case where firms can use closed-loop strategies.

NONRENEWABLE RESOURCE OLIGOPOLIES AND THE CARTEL-FRINGE GAME

We specify and solve a closed-loop dominant firm nonrenewable resource game, with a price-taking fringe. We show that (i) the outcomes of the closed-loop and the open-loop dominant firm nonrenewable resource game (a la Salant 1976) coincide and (ii) when the number of fringe firms becomes arbitrarily large, the equilibrium outcome of the closed-loop oligopoly game does not coincide with the equilibrium outcome of the closed-loop dominant firm nonrenewable resource game. Thus, the interpretation of the dominant firm model, where the fringe is assumed from the outset to be the price-taker, as a limit case of an asymmetric oligopoly where the number of fringe firms tends to infinity, does not extend to the case where firms can use closed-loop strategies.

Paths of the vocational training graduates: Estimation of a multi-state model using a stationary Markov chain.

Located at the hinge of education and employment, vocational training is supposed to provide profiles adapted to the labour market requirements. However, Moroccan graduates of vocational training often find it difficult to fit into the labour market. Indeed, according to the Ministry of Employment and Vocational Training, only 63% of the graduates in 2006 succeeded in integrating the working environment. Yet, this rate hides several realities and is likely to overestimate integration since it does not take into account some crucial variables in the analysis of professional integration, namely the duration of employment, the precariousness of employment, etc. Studies about the paths of vocational training graduates realized periodically (every two years) since 1987 by the Ministry of Employment and Vocational Training aim, by virtue of their longitudinal aspect, to analyze the stability and the evolution of these graduates employment as well as their behaviour. In other words, these studies seek to answer some questions about the dynamics of youth employment in the labour market. This work aims to model the transitions of vocational training graduates using a retrospective calendar recalling their professional situation starting from the date of obtaining the diploma (2002) until the date of the survey (2006). Our model uses a transition process generated by a homogeneous, stationary and ergodic Markov chain for the graduates state space. We propose to explain the transitions from one state to another, via a multivariate logistic link, through variables which can influence between-state transitions. This leads that the processual variables explain these transitions. To estimate the parameters of our model, we use an iterative method of unconstrained nonlinear optimization: Conjugate Gradient "CG”. The stationarity of the Markov chain and the estimation of the transition matrix allow us to compute labour market indicators used to describe the behaviour of young graduates as well as their professional mobility.llabour market, transitions, vocational training, Markov chain, "CG” Method, Morocco

THE OPTIMAL DEPLETION OF EXHAUSTIBLE RESOURCES: A COMPLETE CHARACTERIZATION

We provide the closed form solution to the Dasgupta-Heal-Solow-Stiglitz (DHSS) model. The DHSS model is based on the seminal articles Dasgupta and Heal (Rev. Econ. Stud., 1974), Solow (Rev. Econ. Stud., 1974) and Stiglitz (Rev. Econ. Stud., 1974) and describes an economy with two assets, man-made capital and a nonrenewable resource stock. We explicitly characterize, for such an economy, the dynamics along the optimal trajectory of all the variables in the model and from all possible initial values of the stocks. We use the analytical solution to prove several properties of the optimal consumption path. In particular, we show that the initial consumption under a utilitarian criterion starts below the maximin rate of consumption if and only the resource is abundant enough and that under a utilitarian criterion, it is not necessarily the present generation that benefits most from a windfall of resources.

CARTEL STABILITY IN A DYNAMIC OLIGOPOLY WITH STICKY PRICES

We study the stability of cartels in a differential game model of oligopoly with sticky prices (Fershtman and Kamien 1987). We show that when firms use closed-loop strategies and the rate of increase of the marginal cost is .small enough., the grand coalition (i.e., when the cartel includes all firms) is stable: it is unprofitable for a .firm to exit the cartel. Moreover, a cartel of 3 firms is stable for any positive rate of increase of the marginal cost: it is not profitable for an insider firm to exit the coalition, nor it is profitable for an outsider firm to join the coalition. When firms use open-loop strategies the grand coalition is never stable; moreover, we show that only a cartel of size 2 can be stable and it is so only when the rate of increase of the marginal cost is large enough.

The Build-up of Cooperative Behavior among Non-cooperative Agents

We develop a theoretical model in which each individual is, in some ultimate sense, motivated by purely egoistic satisfaction derived from the goods accruing to him, but there is an implicit social contract such that each performs duties for the others in a way that enhances the satisfaction of all. We introduce a state variable that acts as a proxy for social capital of trustworthiness and that we call the stock of cooperation. We show that noncooperative agents might condition their action on this state variable. Agents build-up the society's stock of cooperation and gradually overcome the free riding problem in a game of private contribution to a public good. We assume that there are neither penalties in the sense of trigger strategies, nor guilt and that each individual is rational. Nous développons un modèle théorique dans lequel les individus sont motivés par la satisfaction égoïste que leur procure l’accumulation de biens, mais où le contrat social incite chaque individu à travailler pour les autres afin d’accroître le bien-être collectif. Nous introduisons une variable d’état représentant le stock de capital social, ou « stock de coopération ». Nous démontrons que cette variable peut influencer les actions des agents non-coopératifs. Les agents accumulent le stock de coopération de la société et réussisent à règler de manière progressive le problème du passager clandestin pour un jeu de contributions privées dans un bien public. Nous supposons qu’il n’existe pas de stratégies de pénalité, de sentiment de culpabilité chez les individus et que chaque agent est rationnel.behavior rule, public goods, stock of cooperation, trust, biens public, confiance, règle de conduite, stock de coopération

GLOBAL DYNAMICS IN A GROWTH MODEL WITH AN EXHAUSTIBLE RESOURCE

We revisit the seminal growth model with exhaustible resources, the so called Dasgupta-Heal-Stiglitz-Solow model (DHSS). For this optimal control problem with two state variables, we explicitly characterize the dynamics of all the variables in the model and from all possible initial values of the stocks. We determine the condition under which consumption is initially increasing with time and the condition under which initial investment is positive implying that overshooting of man-made capital occurs. We show that the initial consumption under a utilitarian criterion starts below the maximin rate of consumption if and only if the resource is abunduant enough and that under a utilitarian criterion, it is not necessarily the present generation that benefits most from a windfall of resources.

Welfare Effect of Mergers and Trade Liberalization

In a two-country model where firms behave à la Cournot, we show that marginal and non-marginal trade liberalization have different effects on the social desirability of horizontal mergers. Marginal tariff reductions increase (decrease) the desirability of merger at sufficiently low (high) tariff levels. In the neighborhood of free trade, for sufficiently low cost savings from merger, trade liberalization increases the desirability of merger whilst decreasing the profitability, implying that mergers should be actively encouraged by competition authorities. Furthermore, we identify ranges of tariff levels for which, if trade liberalization increases (decreases) the desirability of merger, it necessarily increases (decreases) its profitability.

FREE TRADE, AUTARKY AND THE SUSTAINABILITY OF AN INTERNATIONAL ENVIRONMENTAL AGREEMENT

We determine the impact of free trade on the sustainability of an international environmental agreement (IEA) and incorporate it into the assessment of the net benefits of opening up to free trade. We show that such an analysis can reverse the conclusions reached within a standard one-shot game framework. First, we examine a one shot game and argue that the benefits from an increase in economic activity due to free trade outweigh the extra cost of free trade associated with larger environmental damage. Then, we analyze the infinite repetition of the one-shot game where countries can use trigger strategies and show that there exist circumstances where an IEA is sustainable under autarky but not under free trade. This aggravates the environmental damages caused by free trade and leads to the possibility that autarky may welfare dominate free trade. This conclusion remains valid even when countries adopt the most cooperative environmental policy when the "fully cooperative" environmental policy is not sustainable.