International Emission Strategies under the Threat of a Sudden Jump in Damages

We characterize the equilibrium level of emissions, the equilibrium stock of global pollution and the discounted net social welfare for both the cooperative and non-cooperative equilibria when the countries face the threat of a sudden irreversible jump in the global damages at an unknown date. The goal is to analyze the impact of this type of uncertainty on the equilibrium behavior of the countries. We find that it can have a significant effect on those equilibria. Countries reduce their emissions to mitigate their exposure to this threat. As the level of threat rises, countries adjust their emissions to lower the stock of pollutant. However, although initially this threat has the effect of lowering the discounted net welfare, it can in the long run have a net positive effect on welfare. The emissions trajectory is non-monotonic and discontinuous, but only under the threat.Je considère un monde dans lequel les pays souffrent uniformément de la pollution globale. Ils font face à une menace continuelle de voir les dommages causés par cette pollution globale s’accroître subitement de façon irréversible. Je caractérise le niveau des émissions, le stock de pollution, et le niveau de bien-être actualisé en équilibre coopératif et non-coopératif. L’objectif visé est d’analyser l’impact de ce type d’incertitude sur les équilibres issus des comportements stratégiques des pays. Je trouve que cette incertitude peut avoir un effet significatif sur ces équilibres. Les pays réduisent leurs émissions pour mitiger leur exposition à cette menace. Plus la menace est grande, plus les pays ajustent leurs émissions afin de réduire davantage le stock de pollution globale. Cependant, en dépit du fait que cette incertitude diminue le bien-être net initial, elle peut à long terme avoir un effet net positif sur ce bien-être. La trajectoire des émissions est non-monotone et discontinue, mais seulement en présence de la menace

The Effects of the Length of the Period of Commitment on the Size of State International Environmental Agreements

This paper extends the standard model of self-enforcing dynamic international environmental agreements by allowing the length of the period of commitment of such agreements to vary as a parameter. It analyzes the pattern of behavior of the size of stable coalitions, the stock of pollution, and the emission rae as a function of the length of the period of commitment. It is shown that the length of the period of commitment can have very significant effects on the equilibrium. We show numerically that at the initial date, as the length of commitment is increased, the potential gain from cooperation tends to diminish, increasing the disincentive to ratify the agreements. This suggests that considerable attention should be given to the determination of the length of such international agreements

Trade Structure, Transboundary Pollution and Multilateral Trade Liberalization: the Effects on Environmental Taxes and Welfare

This paper considers a trade situation where the production activities of potentially heterogeneous countries generate pollution which can cross borders and harm the well-being of all the countries involved. In each of those countries the policy market levies pollution taxes on the polluting firms and a tariff on imports in order to correct that distortion. The purpose of the paper is to investigate the effect of a reduction in the tariff on equilibrium pollution taxes and welfare. The existing literature has investigated this problem for trade between two identical countries. This paper analyzes the problem in the more realistic context where countries are not necessarily identical and trade can be multilateral. It becomes possible to show what bias is introduced when those two realities are neglected. I find that a tariff reduction can actually lower output; it can also lower welfare even if pollution is purely local.Ce papier s’inscrit dans un contexte où les activités de production des pays potentiellement hétérogènes génèrent de la pollution qui peut traverser les frontières et nuire au bien-être des pays impliqués. Dans chacun de ces pays, l’état s’impose des taxes sur la pollution aux firmes polluantes et des tarifs à l’importation afin de corriger cette distorsion. Ce papier a pour but d’évaluer les effets que pourrait avoir une diminution des tarifs douaniers sur la production, les taxes sur la pollution et le bien-être de ces pays. La littérature existante a étudié ce problème, mais seulement dans le cadre d’un commerce bilatéral entre pays identiques. Cet article fournit un cadre d’analyse plus réaliste dans lequel les pays ne seront pas nécessairement identiques et où le commerce pourra être multilatéral. Il devient alors possible de mettre en évidence le biais introduit en négligeant ces deux facteurs. Dans ce nouveau contexte, je montre qu’une réduction des tarifs d’importation n’augmente pas nécessairement l’output; elle peut aussi nuire au bien-être, même si la pollution est purement locale

The Effects of the Length of the Period of Commitment on the Size of Stable International Environmental Agreements

This paper extends the standard model of self-enforcing dynamic international environmental agreements by allowing the length of the period of commitment of such agreements to vary as a parameter. It analyzes the pattern of behavior of the size of stable coalitions, the stock of pollutant and the emission rate as a function of the length of the period of commitment. It is shown that the length of the period of commitment can have very significant effects on the equilibrium. Three distinct intervals for the length of the period of commitment are identified, across which the equilibrium and its dynamic behavior differ considerably. Whereas for sufficiently high values of the period of commitment only self-enforcing agreements of two countries are possible, for sufficiently low such values full cooperation can be generated. Lengths of periods of commitment between those two thresholds are characterized by an inverse relationship between the length of commitment and the membership size of the agreement. This suggests that considerable attention should be given to the determination of the length of such international agreements

Open Access to the Resource of Antibiotic Treatment Efficacy Subject to Bacterial Resistance

In this paper, we are interested in how a pharmaceutical industry manages existing antibiotic drugs in the context of bacterial resistance. We consider a model based on an epidemiological framework where antibiotic recovery rates, and thus intrinsic qualities, may differ. Antibiotic efficacy is modeled as a common pool of a non-renewable resource to which antibiotic producers have open access. The paper derives antibiotic demands within a vertical differentiation model and characterizes the dynamics of infected individuals, antibiotic efficacy and treatment rates under the open-access and the socially optimal allocation. We show that the high-quality antibiotic drug loses its comparative advantage over time under both allocations, such that the low-quality drug should be used longer. This occurs at a later point of time in the social optimum and allows for a better control of infection in the longer run. In contrast with the ambiguous outcome reported in the literature, the socially optimal steady-state level of antibiotic efficacy is lower than that of the open-access allocation. We also extend our analysis to a strategic, duopolistic context

Essais sur des questions internationales en économie de l'environnement

Cette thèse est constituée de trois articles. Le premier étudie le problème de pollution globale dans un contexte environnemental incertain. Le deuxième article traite des accords internationaux sur l'environnement. Le troisième article montre comment la libéralisation du commerce peut affecter le bien-être et les taxes sur la pollution dans un monde où les pays sont hétérogènes et la pollution transfrontalière. Dans le premier article, je considère un monde dans lequel les pays souffrent uniformément de la pollution globale. Ils font face à une menace continuelle de voir les dommages causés par cette pollution globale s'accroître subitement de façon irréversible. Je caractérise le niveau des émissions, le stock de pollution, et le niveau de bien-être actualisé en équilibres coopératif et non-coopératif. L'objectif visé est d'analyser l'impact de ce type d'incertitude sur les équilibres issus des comportements stratégiques des pays. Je trouve que cette incertitude peut avoir un effet significatif sur ces équilibres. Les pays réduisent leurs émissions pour atténuer leur exposition à cette menace. Plus la menace est grande, plus les pays ajustent leurs émissions afin de réduire le stock de pollution globale. Cependant, en dépit du fait que cette incertitude diminue le bien-être net initial, elle peut à long terme avoir un effet net positif sur le bien-être. Le deuxième article étend la classe des modèles dynamiques standards traitant des accords internationaux sur l'environnement au cas où la durée de la période d'engagement à de tels accords est un paramètre que l'on peut varier de façon exogène. Nous y étudions les évolutions dans le temps de la taille des coalitions stables, du stock de pollution et du taux d'émissions en fonction de la durée d'engagement. Nous montrons que la longueur de la période d'engagement a un effet très significatif sur l'équilibre. Trois intervalles de durée d'engagement sont identifiés pour lesquels l'équilibre et sa dynamique diffèrent considérablement. Alors que pour des durées de la période d'engagement très longues on observe des coalitions stables constituées d'un petit nombre de pays, si ces durées sont suffisamment courtes on peut observer un niveau de coopération élevé. Les durées d'engagement entre ces deux extrêmes sont caractérisées par une relation inverse entre la durée de la période d'engagement et la taille des coalitions stables. Ces faits portent à croire qu'il faudrait accorder une attention toute particulière au choix de la durée d'engagement lors de l'élaboration de tels accords internationaux. Le troisième article s'inscrit dans un contexte où les activités de production des pays potentiellement hétérogènes génèrent de la pollution qui peut traverser les frontières et nuire au bien-être des pays impliqués. Dans chacun de ces pays, l'état impose des taxes sur la pollution aux firmes polluantes et des tarifs à l'importation afin de corriger cette distorsion. Ce papier a pour but d'évaluer les effets que pourrait avoir une diminution des tarifs douaniers sur la production, les taxes sur la pollution et le bien-être de ces pays. La littérature existante a étudié ce problème, mais seulement dans le cadre d'un commerce bilatéral entre pays identiques. Cet article fournit un cadre d'analyse plus réaliste dans lequel les pays ne seront pas nécessairement identiques et où le commerce pourra être multilatéral. Il devient alors possible de mettre en évidence le biais introduit en négligeant ces deux facteurs. Dans ce nouveau contexte, je montre qu'une réduction des tarifs d'importation n'augmente pas nécessairement la production; elle peut aussi nuire au bien-être, même si la pollution est purement locale.This thesis is composed of three papers. The first paper studies the problem of global pollution in the context of environmental uncertainty. The second paper has to do with international environmental agreements. The third paper shows how trade liberalization can affect welfare and pollution taxes in a world of heterogeneous countries and transboundary pollution. In the first paper, I consider a world where countries suffer uniformly from global pollution while facing a continuous threat that the damages from this global pollution will suddenly jump to an irreversible high-damage state. I characterize the equilibrium level of emissions, the equilibrium stock of global pollution and the discounted net social welfare for both the cooperative and non-cooperative equilibria. The purpose is to analyze the impact of this type of uncertainty on the equilibrium behavior of the countries. I find that this uncertainty can have a significant effect on those equilibria. Countries reduce their emissions to mitigate their exposure to that threat. As the level of threat rises, countries adjust their emissions to lower the stock of pollutant. However, although initially this type of uncertainty has the effect of lowering the discounted net welfare, it can in the long run have a net positive effect on welfare. The second paper extends the standard model of self-enforcing dynamic international environmental agreements by allowing the length of the period of commitment of such agreements to vary as a parameter. It analyzes the pattern of behavior of the size of stable coalitions, the stock of pollutant and the emission rate as a function of the length of the period of commitment. It is shown that the length of the period of commitment can have very significant effects on the equilibrium. Three distinct intervals for the length of the period of commitment are identified, across which the equilibrium and its dynamic behavior differ considerably. Whereas for sufficiently high values of the period of commitment only self-enforcing agreements by a small number of countries are possible, for sufficiently low such values cooperation on the part of a very high number of countries can be occur. Lengths of periods of commitment between those two thresholds are characterized by an inverse relationship between the length of commitment and the membership size of the agreement. This suggests that considerable attention should be given to the determination of the length of such international agreements. The third paper considers a trade situation where the production activities of potentially heterogeneous countries generate pollution which can cross borders and harm the well-being of all the countries involved. In each of those countries the policy maker levies pollution taxes on the polluting firms and a tariff on imports in order to correct that distortion. The purpose of the paper is to investigate the effect of a reduction in the tariff on equilibrium pollution taxes and welfare. The existing literature has investigated this problem for trade between two identical countries. This paper analyzes the problem in the more realistic context where countries are not necessarily identical and trade can be multilateral. It becomes possible to show what bias is introduced when those two realities are neglected. I find that a tariff reduction can actually lower output; it can also lower welfare even if pollution is purely local

Innovation and Antibiotic Use within Antibiotic Classes: Market Incentives and Economic Instruments

We analyze a monopolist’s incentive to innovate a new antibiotic which is connected to the same pool of antibiotic treatment efficacy as is another drug produced by a generic industry. We outline the differences of antibiotic use under market conditions and in the social optimum. A time and state-dependent tax-subsidy mechanism is proposed to induce the monopolist and generic industry to exploit antibiotic efficacy optimally

The Effects of the Length of the Period of Commitment on the Size of Stable International Environmental Agreements

This paper extends the standard model of self-enforcing dynamc international environmental agreements by allowing the length of the period of commitment of such agreements to vary as a parameter. It analyzes the pattern of behavior of the size of stable coalitions, the stock of pollution, and the emission rate as a function of the length of the period of commitment. It is shown that the length of the period of commitment can have very significant effects on the equilibrium. We show numerically that at the initial date, as the length of commitment is increased, the potential gain from cooperation tends to diminish, increasing the disincentive to ratify the agreements. This suggests that considerable attention should be given to the determination of the length of such international agreements

International Emission Strategies under the Threat of a Sudden Jump in Damages

We characterize the equilibrium level of emissions, the equilibrium stock of global pollution and the discounted net social welfare for both the cooperative and non-cooperative equilibria when the countries face the threat of a sudden irreversible jump in the global damages at an unknown date. The goal is to analyze the impact of this type of uncertainty on the equilibrium behavior of the countries. We find that it can have a significant effect on those equilibria. Countries reduce their emissions to mitigate their exposure to this threat. As the level of threat rises, countries adjust their emissions to lower the stock of pollutant. However, although initially this threat has the effect of lowering the discounted net welfare, it can in the long run have a net positive effect on welfare. The emissions trajectory is non-monotonic and discontinuous, but only under the threat.Global pollution, environmental uncertainty, regime shift, stochastic differential games