Can education be good for both growth and the environment?

We develop an overlapping generations model of growth and the environment with public policy on education. Beyond the traditional mechanisms through which knowledge, growth and the environment interplay, we stress out the role played by education on environmental awareness. Assuming first that environmental awareness is constant, we show the existence of a balanced growth path along which environmental quality increases continually. Then, if education enhances environmental awareness, the equilibrium properties are modi?ed: the economy can reach a steady state or converge to an asymptotic balanced growth path. Therefore, education does not necessarily promote sustained and sustainable growth.overlapping generations, public education, environmental maintenance, green awareness, sustainable growth

Global emission ceiling versus international cap and trade: What is the most efficient system when countries act non-cooperatively?

We model climate negotiations as a two-stage game. In the first stage of the game, players have to agree on a global emission cap (GEC). In the second stage, they non-cooperatively choose either their emission level or their emission quota, depending on whether emission trading is allowed, under the cap that potentially binds them together. A three heterogenous player quadratic game serves as a base for the analysis. In this framework, when the cap is non-binding, there exists a unique Nash equilibrium. When the emission cap is binding, among all the coupled constraints Nash equilibria, we select a normalized equilibrium by solving a variational inequality, which has a unique solution. In both scenarios – with and without emission trading – we show that there exists a non-empty range of values for which setting a binding cap improves all players’ payoff. It also appears that for some values of the cap, all players get a higher payoff under the GEC system alone than under the international cap and trade (ITC) system alone. Thus, the introduction of a GEC outperforms the ITC system both in terms of emission reduction and of payoff gains.environmental game, climate change, international cap and trade system, national emission quotas, global emission cap, normalized equilibria, variational and quasi-variational inequalities.

Double Irreversibility and Environmental Policy Design

The design of environmental policy typically takes place within a framework in which uncertainty over the future impact of pollution and two different kinds of irreversibilities interact. The first kind of irreversibility concerns the sunk cost of environmental degradation; the second is related to the sunk cost of environmental policy. Clearly, the two irreversibilities pull in opposite directions: policy irreversibility leads to more pollution and a less/later policy while environmental irreversibility generates less pollution and a more/sooner policy. Using a real option approach and an infinite time horizon model, this paper considers both irreversibilities simultaneously. The model first is developed by paying particular attention to the option values related to pollution and policy adoption. Solving the model in closed form then provides solutions for both the optimal pollution level and the optimal environmental policy timing. Finally, the model is "calibrated" with the purpose of appraising which irreversibility has the prevailing effect and what is the overall impact of both irreversibilities on pollution and policy design.Environmental Policy, Environmental Irreversibility, Policy Irreversibility

The Environmental Kuznets Curve in a World of Irreversibility

We develop an overlapping generations model where consumption is the source of polluting emissions. Pollution stock accumulates with emissions but is partially assimilated by nature at each period. The assimilation capacity of nature is limited and vanishes beyond a critical level of pollution. We first show that multiple equilibria exist. More importantly, some exhibit irreversible pollution levels although an abatement activity is operative. Thus, the simple engagement of maintenance does not necessarily suffice to protect an economy against convergence toward a steady state having the properties of an ecological and economic poverty trap. In contrast with earlier related studies, the emergence of the environmental Kuznets curve is no longer the rule. Instead, we detect a sort of degenerated Environmental Kuznets Curve that corresponds to the equilibrium trajectory leading to the irreversible solution

Public infrastructure, non cooperative investments and endogeneous growth

This paper develops a two-country general equilibrium model with endogenous growth where governements behave strategically in the provision of productive infrastructure. The public capitals enter both national and foreign production as an external input, and they are financed by a flat tax on income. In the private sector, firms and households take the public policy as given when making their decisions. It is shown that both a Markov Perfect Equillibrium (MPE) and a Centralized Solution (CS) exist, even when the parameters allow for endogenous growth, therefore explosive paths for the state variables. And the dynamic analysis reveals three important features. Firstly, under constant returns, the two countries' growth rates differ during the transition but are identical on the balanced growth path. Secondly, due to the infrastructure externality, assuming away constant returns to scale a country with decreasing returns can experience sustained growth provided that the other grows at a positive constant rate. Thirdly, Nash growth rates are compared with the centralized rates. We show that cooperation in infrastructure provision does not necessarily lead to higher growth for each country. We also show that, in some configurations of households' preferences and initial conditions, cooperation would call for a recession in the initial stages of development, whereas strategic investments would not. Lastly, depending also on the configuration of preferences, we show that cooperation can increase or decrease the gap between countries' growth rates.

Technological vs ecological switch and the environmental Kuznets curve

We consider an optimal technology adoption AK model in line with Boucekkine Krawczyk and Vallée (2011): an economy, caring about consumption and pollution as well, starts with a given technological regime and may decide to switch at any moment to a cleaner technology at a given permanent or transitory output cost. At the same time, we posit that there exists a pollution threshold above which the assimilation capacity of Nature goes down, featuring a kind of irreversible ecological regime. We study how ecological irreversibility interacts with the ingredients of the latter optimal technological switch problem, with a special attention to induced capital-pollution relationship. We find that if a single technological switch is optimal, one recovers the Environmental Kuznets Curve provided initial pollution is high enough. If exceeding the ecological threshold is optimal, then the latter configuration is far from being the rule.Technology adoption; ecological irreversibility; Environmental Kuznets Curve; Multi-stage optimal control

Public Infrastructure, non Cooperative Investments and Endogenous Growth

This paper develops a two-country general equilibrium model with endogenous growth where governments behave strategically in the provision of productive infrastructure. The public capitals enter both national and foreign production as an external input, and they are …nanced by a at tax on income. In the private sector, fi…rms and households take the public policy as given when making their decisions. For arbitrary constant tax rates, the dynamic analysis reveals two important features. Firstly, under constant returns, the two countries growth rates differ during the transition but are identical on the balanced growth path. Secondly, due to the infrastructure externality, assuming away constant returns to scale a country with decreasing returns can experience sustained growth provided that the other grows at a positive constant rate. Then we endogeneize tax rates. It is shown that both a Markov Perfect Equilibrium (MPE) and a Centralized Solution (CS) exist, even when the parameters allow for endogenous growth, therefore explosive paths for the state variables. Nash growth rates are compared with the centralized rates. We show that cooperation in infrastructure provision does not necessarily lead to higher growth for each country. We also show that, in some con…gurations of households' preferences and initial conditions, cooperation would call for a slowdown in the initial stages of development, whereas strategic investments would not. Lastly, depending also on the con…guration of preferences, we show that cooperation can increase or decrease the gap between countries' growth rates.

Robust control of a bimorph mirror for adaptive optics system

We apply robust control technics to an adaptive optics system including a dynamic model of the deformable mirror. The dynamic model of the mirror is a modification of the usual plate equation. We propose also a state-space approach to model the turbulent phase. A continuous time control of our model is suggested taking into account the frequential behavior of the turbulent phase. An H_\infty controller is designed in an infinite dimensional setting. Due to the multivariable nature of the control problem involved in adaptive optics systems, a significant improvement is obtained with respect to traditional single input single output methods

Optimal Emission-Extraction Policy in a World of Scarcity and Irreversibility

This paper extends the classical exhaustible-resource/stock-pollution model with irreversibility of pollution decay, meaning that after reaching some threshold there is no decay of the pollution stock. Within this framework, we answer the question how the potential irreversibility of pollution affects the extraction path. We investigate the conditions under which the economy will optimally adopt a reversible policy, and when it is optimal to enter the irreversible region. In the case of irreversibility it may be optimal to leave a positive amount of resource in the ground forever. As far as the optimal extraction/emission policy is concerned, several types of solutions may arise, including solutions where the economy stays at the threshold for a while. Given that different programs may satisfy the first order conditions for optimality, we further investigate when each of these is optimal. The analysis is illustrated by means of a calibrated example. To sum up, for any pollution level, we can identify a critical resource stock such that there exist multiple optima i.e. a reversible and an irreversible policy that yield exactly the same present value. For any resource stock below this critical value, the optimal policy is reversible whereas with large enough resources, irreversible policies outperform reversible programs. Finally, the comparison between irreversible policies reveals that it is never optimal for the economy to stay at the threshold for a while before entering the irreversible region.non-renewable resource, irreversible pollution, optimal policy

Optimal Emission Policy under the Risk of Irreversible Pollution

We consider an optimal consumption and pollution problem that has two important features. Environmental damages due to economic activities may be irreversible and the level at which the degradation becomes irreversible is unknown. Particular attention is paid to the situation where agents are relatively impatient and/or do not care a lot about the environment and/or Nature regenerates at low rate. We show that the optimal policy of the uncertain problem drives the economy in the long run toward a steady state while, when ignoring irreversibility, the economy follows a balanced growth path accompanied by a perpetual decrease in environmental quality and consumption, both asymptotically converging toward zero. Therefore, accounting for the risk of irreversibility induces more conservative decisions regarding consumption and polluting emissions. In general, however, we cannot rule out situations where the economy will optimally follow an irreversible path and consequently, will also be left, in the long run, with an irreversibly degraded environment.Optimal Control, Irreversibility Threshold, Uncertainty, Optimal Reversible, Irreversible Policy