Il cambiamento climatico e la pressione antropica sulle risorse idriche rendono le politiche di gestione dell’acqua primordiali nell'agenda dei policy makers. Nel mio lavoro, inizialmente, presento una rassegna della letteratura in materia di modelli di Equilibro Generale Calcolabile (CGE) che incorporano l’acqua. In tale ambito, propongo la seguente classificazione: (i) la concorrenza tra i settori per l’uso di acqua; (ii) le politiche di prezzo e delle tariffe sull’acqua, (iii) l'acqua e le questioni commerciali, (iv) i modelli CGE ed altri modelli. In secondo luogo, analizzo gli effetti della siccità per l'economia del Kenya attraverso un modello CGE statico, calibrato sulla Matrice di Contabilità Sociale (SAM) del Kenya (2003). Il Kenya è stato scelto perché Paese particolarmente esposto a ricorrenti siccità (ad esempio negli anni 1994, 1998-2000, 2001 e 2003) che hanno duramente colpito le popolazioni più vulnerabili del paese, cioè quelle concentrate nelle zone aride e semiaride (ASAL). Inoltre, propongo l'introduzione di schemi di tassazione, al fine di produrre un extra-reddito che possa essere reinvestito per aumentare l'efficienza del settore idrico in Kenya o per trasferimenti alle famiglie rurali più povere. Infine, riproduco l'attuazione del progetto “Arid Land and Resource Management Project” (ALRMP) di FAO e Banca Mondiale. I risultati mostrano che, in primo luogo, gli effetti di una riduzione della dotazione di acqua sono più robusti di quelli derivanti da un aumento della dotazione d'acqua. In secondo luogo, la simulazione di uno scenario di siccità - in cui non solo la dotazione di acqua, ma anche la disponibilità di terra e la produttività di attività selezionate sono ridotti - fornisce un quadro più coerente dei risultati. In terzo luogo, tassare “raw water” (il fattore di acqua) può influenzare negativamente i redditi degli abitanti delle zone rurali. Infine, Il ALRMP ha un impatto positivo sulla riduzione degli effetti negativi della siccità sulle ASAL in Kenya. / Climate change and human pressure on water resources make water management policies primordial in the agenda of policy makers. I first propose a literature review of the works on Water Computable General Equilibrium (CGE) Models suggesting the following classification: (i) competition between sectors; (ii) water pricing policies and tariffs; (iii) water and trade issues; (iv) CGE and other models. Secondly, the effects of droughts on the Kenyan economy are studied by means of a static CGE model, calibrated on the 2003 Social Accounting Matrix (SAM) of Kenya. As a water scarce Sub-Saharan country, Kenya is among those countries considered particularly exposed to drought problems. This has been witnessed in recent years by several recurring droughts (1994, 1998-2000, 2001, and 2003) which have harshly hit the most vulnerable part of the country, namely the Arid and Semi Arid Lands (ASAL). Besides, I propose the introduction of several taxation schemes in order to produce an extra revenue to be either reinvested in increasing the efficiency of the water sector in Kenya, or redistributed to the poorest rural households. Finally we simulate the implementation of the UN-FAO and World Bank “Arid Land and Resource Management Project” (ALRMP). The results show that, firstly, the effects of reducing water endowment are stronger than when increasing water endowment. Secondly, simulating a drought scenario – where not just water endowment but also availability of land and the productivity of selected activities are reduced - gives a more coherent picture of the outcomes. Thirdly, taxing raw water (the water factor) may negatively affect rural dwellers as they are owners of water resources. Finally, I found that the ALRMP has a positive impact on mitigating the negative effects of droughts in Kenyan ASAL.

This dissertation contains three essays on environmental economics and on credit market imperfections. The literature on carbon tax incidence generally finds that carbon taxes have a regressive impact on the distribution of income. The main reason for that finding stems from the fact that poor households spend a larger share of their total expenditure on energy products than the rich households do. This literature, however, has ignored the impact of carbon taxes on income stemming from changes in relative factor prices. Yet, changes in household welfare depend not only on variations in commodity prices, but also on changes in income. Chapter 1 provides a comprehensive analysis of the distributional impact of carbon taxes on inequality by considering both demand-side and supply-side channels. We use a multi-sector, multi-household general equilibrium model to analyze the distributional impact of carbon taxes on inequality. Using equivalent income as the household welfare metric, we apply the Shapley value and concentration index approaches to decomposing household inequality. Our simulation results suggest that carbon taxes exert a larger negative impact on the income of the rich than that of the poor, and are thereby progressive. On the other hand, when assessed from the use side alone (i.e., commodity prices alone), our results confirm previous findings, whereas carbon taxes are regressive. However, due to the stronger incidence of carbon taxes on inequality from the income side, our results suggest that the carbon tax tends to reduce inequality. These findings further suggest that the traditional approach of assessing the impact of carbon taxes on inequality through changes in commodity prices alone may be misleading. Chapter 2 investigates the economic impacts of creating an emissions bubble between Canada and the US in a context of subglobal participation in efforts to reduce pollution with market based-instruments. One of the advantages of an emissions bubble is that it can be beneficial to countries that differ in their production and consumption patterns. To address the competitiveness issue that arises from the free-rider problem in the area of climate-change mitigation, we consider the imposition of a border tax adjustment (BTA) - a commonly suggested solution in the literature. We develop a detailed multisector and multi-regional general equilibrium model to analyze the welfare, aggregate, sectoral and trade impacts of the formation of an emissions bubble between Canada and the US with and without BTA. Our simulation results suggest that, in the absence of BTA, the creation of the bubble would make both countries better off through a positive terms-of-trade effect, and more importantly, through a significant reduction in Canada’s marginal abatement cost. The benefits of these positive effects would spill over to the non-participating countries, leading them to increase their trade shares in non-emissions-intensive goods. Moreover, the simulation results also indicate that a unilateral implementation of a BTA by any one of the two countries is welfare deteriorating in the imposing country and welfare improving in the other. In contrast, a joint implementation of a BTA by the two countries would make Canada better off and the US worse off. Chapter 3 shows that learning by lending is a potential channel of understanding the business cycle fluctuation under an imperfect credit market. An endogenous link among the learning parameter, lending rates, and the size of investment makes it possible to generate an internal propagation even due to a temporary shock. The main finding of this chapter is the explanation of how ex post non-financial factors such as information losses by individual agents in a credit market may account for a persistence in real indicators such as capital stock and output.

Submitted by Lucas Pedreira do Couto Ferraz (lucaspcf@gmail.com) on 2010-09-28T19:40:07Z No. of bitstreams: 1 Thesis_PhD.pdf: 996294 bytes, checksum: cf266060bc6c236aa36c8a4e4775224d (MD5) / Approved for entry into archive by Andrea Virginio Machado(andrea.machado@fgv.br) on 2010-09-29T12:58:30Z (GMT) No. of bitstreams: 1 Thesis_PhD.pdf: 996294 bytes, checksum: cf266060bc6c236aa36c8a4e4775224d (MD5) / Made available in DSpace on 2010-10-01T17:44:05Z (GMT). No. of bitstreams: 1 Thesis_PhD.pdf: 996294 bytes, checksum: cf266060bc6c236aa36c8a4e4775224d (MD5) Previous issue date: 2010-04-16 / This work presents a fully operational interstate CGE model implemented for the Brazilian economy that tries to quantify both the role of barriers to trade on economic growth and foreign trade performance and how the distribution of the economic activity may change as the country opens up to foreign trade. Among the distinctive features embedded in the model, modeling of external scale economies, port efficiency and land-maritime transport costs provides an innovative way of dealing explicitly with theoretical issues related to integrated regional systems. In order to illustrate the role played by the quality of infrastructure and geography on the country‟s foreign and interregional trade performance, a set of simulations is presented where barriers to trade are significantly reduced. The relative importance of trade policy, port efficiency and land-maritime transport costs for the country trade relations and regional growth is then detailed and quantified, considering both short run as well as long run scenarios. A final set of simulations shed some light on the effects of liberal trade policies on regional inequality, where the manufacturing sector in the state of São Paulo, taken as the core of industrial activity in the country, is subjected to different levels of external economies of scale. Short-run core-periphery effects are then traced out suggesting the prevalence of agglomeration forces over diversion forces could rather exacerbate regional inequality as import barriers are removed up to a certain level. Further removals can reverse this balance in favor of diversion forces, implying de-concentration of economic activity. In the long run, factor mobility allows a better characterization of the balance between agglomeration and diversion forces among regions. Regional dispersion effects are then clearly traced-out, suggesting horizontal liberal trade policies to benefit both the poorest regions in the country as well as the state of São Paulo. This long run dispersion pattern, on one hand seems to unravel the fragility of simple theoretical results from recent New Economic Geography models, once they get confronted with more complex spatially heterogeneous (real) systems. On the other hand, it seems to capture the literature‟s main insight: the possible role of horizontal liberal trade policies as diversion forces leading to a more homogeneous pattern of interregional economic growth.

This dissertation contains three essays on environmental economics and on credit market imperfections. The literature on carbon tax incidence generally finds that carbon taxes have a regressive impact on the distribution of income. The main reason for that finding stems from the fact that poor households spend a larger share of their total expenditure on energy products than the rich households do. This literature, however, has ignored the impact of carbon taxes on income stemming from changes in relative factor prices. Yet, changes in household welfare depend not only on variations in commodity prices, but also on changes in income. Chapter 1 provides a comprehensive analysis of the distributional impact of carbon taxes on inequality by considering both demand-side and supply-side channels. We use a multi-sector, multi-household general equilibrium model to analyze the distributional impact of carbon taxes on inequality. Using equivalent income as the household welfare metric, we apply the Shapley value and concentration index approaches to decomposing household inequality. Our simulation results suggest that carbon taxes exert a larger negative impact on the income of the rich than that of the poor, and are thereby progressive. On the other hand, when assessed from the use side alone (i.e., commodity prices alone), our results confirm previous findings, whereas carbon taxes are regressive. However, due to the stronger incidence of carbon taxes on inequality from the income side, our results suggest that the carbon tax tends to reduce inequality. These findings further suggest that the traditional approach of assessing the impact of carbon taxes on inequality through changes in commodity prices alone may be misleading. Chapter 2 investigates the economic impacts of creating an emissions bubble between Canada and the US in a context of subglobal participation in efforts to reduce pollution with market based-instruments. One of the advantages of an emissions bubble is that it can be beneficial to countries that differ in their production and consumption patterns. To address the competitiveness issue that arises from the free-rider problem in the area of climate-change mitigation, we consider the imposition of a border tax adjustment (BTA) - a commonly suggested solution in the literature. We develop a detailed multisector and multi-regional general equilibrium model to analyze the welfare, aggregate, sectoral and trade impacts of the formation of an emissions bubble between Canada and the US with and without BTA. Our simulation results suggest that, in the absence of BTA, the creation of the bubble would make both countries better off through a positive terms-of-trade effect, and more importantly, through a significant reduction in Canada’s marginal abatement cost. The benefits of these positive effects would spill over to the non-participating countries, leading them to increase their trade shares in non-emissions-intensive goods. Moreover, the simulation results also indicate that a unilateral implementation of a BTA by any one of the two countries is welfare deteriorating in the imposing country and welfare improving in the other. In contrast, a joint implementation of a BTA by the two countries would make Canada better off and the US worse off. Chapter 3 shows that learning by lending is a potential channel of understanding the business cycle fluctuation under an imperfect credit market. An endogenous link among the learning parameter, lending rates, and the size of investment makes it possible to generate an internal propagation even due to a temporary shock. The main finding of this chapter is the explanation of how ex post non-financial factors such as information losses by individual agents in a credit market may account for a persistence in real indicators such as capital stock and output.

Thesis Abstract: Chapter I: Regional burden sharing of GHG mitigation policies – A Canadian perspective. The distribution of the burden of cost arising from the reduction of greenhouse gas (GHG) emissions is a contentious issue in policy discussions; more so among regional jurisdictions in the federalist countries with decentralized authorities over environmental regulations. In this setting, often the policy discussions are focused on the distribution of regional emission reduction targets that, in turn, entails negotiations over the distribution of the scarcity rents and the regional transfers of wealth. The allocation of regional emission entitlements is thus a key factor that could hinder the political feasibility of a national GHG mitigation policy. In this paper, we build a multi-region computable general equilibrium (CGE) model of the Canadian economy to assess the implications of different burden sharing rules governing the national GHG abatement policy with a cap-and-trade system of emission permits. In addition to assessing the impacts of traditional regional emissions allocation rules that involve intra-regional transfers of wealth, we consider a particular emission allocation that avoids such transfers, which may be a more palatable option given the context of likely fierce negotiations over the issue. Our results indicate to differing outcomes depending on the allocation policy in use. The CGE framework is also able to shed light on the transmission mechanisms that drive the results underlying the policy options. Chapter II: Endogenous technological change and emission allowances. Given the imminent threat of global warming due to GHG emissions, a number of emission mitigation policies have been proposed in the literature. However, they generally suffer from the classical equity-efficiency trade-off. High costs from equity concerns often render environmental policies politically unattractive and thus hard to implement. Recent advancement in the climate policy modeling literature that incorporates endogenous technological change (ETC) into the framework can potentially bring new insights into this debate. Using an inter-temporal, multi-sector CGE approach with ETC incorporated into the framework, this paper builds a model that focuses on the equity-efficiency debate for the policymakers. Canada is chosen as the country of investigation for this purpose. The paper provides a new welfare ranking of four permit allocation policies that address the equity-efficiency trade-off. In a second-best setting with pre-existing distortions, output-based allocation (OBA) of emission permits is compared to three other policy options: (i) an emissions trading system with grandfathered allocation (GFA), (ii) an auction permit trading system where permit revenue is recycled to lower payroll taxes (RPT), and (iii) a hybrid of OBA and R&D subsidy (O-R&D). We find that adapting OBA, as well as O-R&D, is welfare improving over GFA. The implicit output subsidy, entailed in the OBA policy, mitigates against the rising cost effect in the GFA policy. This is reinforced through added investment incentive in R&D when ETC in incorporated into the framework. With O-R&D, since the R&D subsidy corrects for market imperfections in the knowledge accumulation process, the effect is further bolstered, culminating into mitigation of uneven distributional outcome for energy-intensive industries as a whole. Contrary to previous results, we also find that, in terms of the welfare metric, OBA unequivocally improves the distributional outcome across sectors as compared to the RPT policy. Inclusion of ETC also unequivocally generates a higher welfare ranking for all permit policy schemes. Chapter III: Emission permit banking and induced technological change. This paper attempts to undertake an exploratory research by integrating two themes in the emission mitigation policy literature, which include: the inter-temporal emission permit banking and borrowing and the role of induced technological change in emission mitigation. Using a simple optimal control approach, we construct a unified framework that evaluates the optimal path of emissions and the optimal trajectory of permit price when both inter-temporal banking and borrowing of permits and the effects of induced technological change (ITC) are present. We find that ITC leads to a declining emission trajectory over time. The effect of ITC on the optimal permit price path, however, is ambiguous and critically depends on the extent of marginal cost saving that emanates from emission-saving technological innovation.

Thesis Abstract: Chapter I: Regional burden sharing of GHG mitigation policies – A Canadian perspective. The distribution of the burden of cost arising from the reduction of greenhouse gas (GHG) emissions is a contentious issue in policy discussions; more so among regional jurisdictions in the federalist countries with decentralized authorities over environmental regulations. In this setting, often the policy discussions are focused on the distribution of regional emission reduction targets that, in turn, entails negotiations over the distribution of the scarcity rents and the regional transfers of wealth. The allocation of regional emission entitlements is thus a key factor that could hinder the political feasibility of a national GHG mitigation policy. In this paper, we build a multi-region computable general equilibrium (CGE) model of the Canadian economy to assess the implications of different burden sharing rules governing the national GHG abatement policy with a cap-and-trade system of emission permits. In addition to assessing the impacts of traditional regional emissions allocation rules that involve intra-regional transfers of wealth, we consider a particular emission allocation that avoids such transfers, which may be a more palatable option given the context of likely fierce negotiations over the issue. Our results indicate to differing outcomes depending on the allocation policy in use. The CGE framework is also able to shed light on the transmission mechanisms that drive the results underlying the policy options. Chapter II: Endogenous technological change and emission allowances. Given the imminent threat of global warming due to GHG emissions, a number of emission mitigation policies have been proposed in the literature. However, they generally suffer from the classical equity-efficiency trade-off. High costs from equity concerns often render environmental policies politically unattractive and thus hard to implement. Recent advancement in the climate policy modeling literature that incorporates endogenous technological change (ETC) into the framework can potentially bring new insights into this debate. Using an inter-temporal, multi-sector CGE approach with ETC incorporated into the framework, this paper builds a model that focuses on the equity-efficiency debate for the policymakers. Canada is chosen as the country of investigation for this purpose. The paper provides a new welfare ranking of four permit allocation policies that address the equity-efficiency trade-off. In a second-best setting with pre-existing distortions, output-based allocation (OBA) of emission permits is compared to three other policy options: (i) an emissions trading system with grandfathered allocation (GFA), (ii) an auction permit trading system where permit revenue is recycled to lower payroll taxes (RPT), and (iii) a hybrid of OBA and R&D subsidy (O-R&D). We find that adapting OBA, as well as O-R&D, is welfare improving over GFA. The implicit output subsidy, entailed in the OBA policy, mitigates against the rising cost effect in the GFA policy. This is reinforced through added investment incentive in R&D when ETC in incorporated into the framework. With O-R&D, since the R&D subsidy corrects for market imperfections in the knowledge accumulation process, the effect is further bolstered, culminating into mitigation of uneven distributional outcome for energy-intensive industries as a whole. Contrary to previous results, we also find that, in terms of the welfare metric, OBA unequivocally improves the distributional outcome across sectors as compared to the RPT policy. Inclusion of ETC also unequivocally generates a higher welfare ranking for all permit policy schemes. Chapter III: Emission permit banking and induced technological change. This paper attempts to undertake an exploratory research by integrating two themes in the emission mitigation policy literature, which include: the inter-temporal emission permit banking and borrowing and the role of induced technological change in emission mitigation. Using a simple optimal control approach, we construct a unified framework that evaluates the optimal path of emissions and the optimal trajectory of permit price when both inter-temporal banking and borrowing of permits and the effects of induced technological change (ITC) are present. We find that ITC leads to a declining emission trajectory over time. The effect of ITC on the optimal permit price path, however, is ambiguous and critically depends on the extent of marginal cost saving that emanates from emission-saving technological innovation.

Thesis Abstract: Chapter I: Regional burden sharing of GHG mitigation policies – A Canadian perspective. The distribution of the burden of cost arising from the reduction of greenhouse gas (GHG) emissions is a contentious issue in policy discussions; more so among regional jurisdictions in the federalist countries with decentralized authorities over environmental regulations. In this setting, often the policy discussions are focused on the distribution of regional emission reduction targets that, in turn, entails negotiations over the distribution of the scarcity rents and the regional transfers of wealth. The allocation of regional emission entitlements is thus a key factor that could hinder the political feasibility of a national GHG mitigation policy. In this paper, we build a multi-region computable general equilibrium (CGE) model of the Canadian economy to assess the implications of different burden sharing rules governing the national GHG abatement policy with a cap-and-trade system of emission permits. In addition to assessing the impacts of traditional regional emissions allocation rules that involve intra-regional transfers of wealth, we consider a particular emission allocation that avoids such transfers, which may be a more palatable option given the context of likely fierce negotiations over the issue. Our results indicate to differing outcomes depending on the allocation policy in use. The CGE framework is also able to shed light on the transmission mechanisms that drive the results underlying the policy options. Chapter II: Endogenous technological change and emission allowances. Given the imminent threat of global warming due to GHG emissions, a number of emission mitigation policies have been proposed in the literature. However, they generally suffer from the classical equity-efficiency trade-off. High costs from equity concerns often render environmental policies politically unattractive and thus hard to implement. Recent advancement in the climate policy modeling literature that incorporates endogenous technological change (ETC) into the framework can potentially bring new insights into this debate. Using an inter-temporal, multi-sector CGE approach with ETC incorporated into the framework, this paper builds a model that focuses on the equity-efficiency debate for the policymakers. Canada is chosen as the country of investigation for this purpose. The paper provides a new welfare ranking of four permit allocation policies that address the equity-efficiency trade-off. In a second-best setting with pre-existing distortions, output-based allocation (OBA) of emission permits is compared to three other policy options: (i) an emissions trading system with grandfathered allocation (GFA), (ii) an auction permit trading system where permit revenue is recycled to lower payroll taxes (RPT), and (iii) a hybrid of OBA and R&D subsidy (O-R&D). We find that adapting OBA, as well as O-R&D, is welfare improving over GFA. The implicit output subsidy, entailed in the OBA policy, mitigates against the rising cost effect in the GFA policy. This is reinforced through added investment incentive in R&D when ETC in incorporated into the framework. With O-R&D, since the R&D subsidy corrects for market imperfections in the knowledge accumulation process, the effect is further bolstered, culminating into mitigation of uneven distributional outcome for energy-intensive industries as a whole. Contrary to previous results, we also find that, in terms of the welfare metric, OBA unequivocally improves the distributional outcome across sectors as compared to the RPT policy. Inclusion of ETC also unequivocally generates a higher welfare ranking for all permit policy schemes. Chapter III: Emission permit banking and induced technological change. This paper attempts to undertake an exploratory research by integrating two themes in the emission mitigation policy literature, which include: the inter-temporal emission permit banking and borrowing and the role of induced technological change in emission mitigation. Using a simple optimal control approach, we construct a unified framework that evaluates the optimal path of emissions and the optimal trajectory of permit price when both inter-temporal banking and borrowing of permits and the effects of induced technological change (ITC) are present. We find that ITC leads to a declining emission trajectory over time. The effect of ITC on the optimal permit price path, however, is ambiguous and critically depends on the extent of marginal cost saving that emanates from emission-saving technological innovation.

Thesis Abstract: Chapter I: Regional burden sharing of GHG mitigation policies – A Canadian perspective. The distribution of the burden of cost arising from the reduction of greenhouse gas (GHG) emissions is a contentious issue in policy discussions; more so among regional jurisdictions in the federalist countries with decentralized authorities over environmental regulations. In this setting, often the policy discussions are focused on the distribution of regional emission reduction targets that, in turn, entails negotiations over the distribution of the scarcity rents and the regional transfers of wealth. The allocation of regional emission entitlements is thus a key factor that could hinder the political feasibility of a national GHG mitigation policy. In this paper, we build a multi-region computable general equilibrium (CGE) model of the Canadian economy to assess the implications of different burden sharing rules governing the national GHG abatement policy with a cap-and-trade system of emission permits. In addition to assessing the impacts of traditional regional emissions allocation rules that involve intra-regional transfers of wealth, we consider a particular emission allocation that avoids such transfers, which may be a more palatable option given the context of likely fierce negotiations over the issue. Our results indicate to differing outcomes depending on the allocation policy in use. The CGE framework is also able to shed light on the transmission mechanisms that drive the results underlying the policy options. Chapter II: Endogenous technological change and emission allowances. Given the imminent threat of global warming due to GHG emissions, a number of emission mitigation policies have been proposed in the literature. However, they generally suffer from the classical equity-efficiency trade-off. High costs from equity concerns often render environmental policies politically unattractive and thus hard to implement. Recent advancement in the climate policy modeling literature that incorporates endogenous technological change (ETC) into the framework can potentially bring new insights into this debate. Using an inter-temporal, multi-sector CGE approach with ETC incorporated into the framework, this paper builds a model that focuses on the equity-efficiency debate for the policymakers. Canada is chosen as the country of investigation for this purpose. The paper provides a new welfare ranking of four permit allocation policies that address the equity-efficiency trade-off. In a second-best setting with pre-existing distortions, output-based allocation (OBA) of emission permits is compared to three other policy options: (i) an emissions trading system with grandfathered allocation (GFA), (ii) an auction permit trading system where permit revenue is recycled to lower payroll taxes (RPT), and (iii) a hybrid of OBA and R&D subsidy (O-R&D). We find that adapting OBA, as well as O-R&D, is welfare improving over GFA. The implicit output subsidy, entailed in the OBA policy, mitigates against the rising cost effect in the GFA policy. This is reinforced through added investment incentive in R&D when ETC in incorporated into the framework. With O-R&D, since the R&D subsidy corrects for market imperfections in the knowledge accumulation process, the effect is further bolstered, culminating into mitigation of uneven distributional outcome for energy-intensive industries as a whole. Contrary to previous results, we also find that, in terms of the welfare metric, OBA unequivocally improves the distributional outcome across sectors as compared to the RPT policy. Inclusion of ETC also unequivocally generates a higher welfare ranking for all permit policy schemes. Chapter III: Emission permit banking and induced technological change. This paper attempts to undertake an exploratory research by integrating two themes in the emission mitigation policy literature, which include: the inter-temporal emission permit banking and borrowing and the role of induced technological change in emission mitigation. Using a simple optimal control approach, we construct a unified framework that evaluates the optimal path of emissions and the optimal trajectory of permit price when both inter-temporal banking and borrowing of permits and the effects of induced technological change (ITC) are present. We find that ITC leads to a declining emission trajectory over time. The effect of ITC on the optimal permit price path, however, is ambiguous and critically depends on the extent of marginal cost saving that emanates from emission-saving technological innovation.

Simulationsmodelle sind ein etabliertes Instrument zur Analyse von Auswirkungen exogener Schocks in komplexen Systemen. Die in jüngster Zeit gestiegene verfügbare Rechenleistung und -geschwindigkeit hat die Entwicklung detaillierterer und komplexerer Simulationsmodelle befördert. Dieser Trend hat jedoch Bedenken hinsichtlich der Unsicherheit solcher Modellergebnisse aufgeworfen und daher viele Nutzer von Simulationsmodellen dazu motiviert, Unsicherheiten in ihren Simulationen zu integrieren. Eine Möglichkeit dies systematisch zu tun besteht darin, stochastische Elemente in die Modellgleichungen zu integrieren, wodurch das jeweilige Modell zu einem Problem (mehrfacher) numerischer Integrationen wird. Da es für solche Probleme meist keine analytischen Lösungen gibt, werden numerische Approximationsmethoden genutzt. Die derzeit zur Quantifizierung von Unsicherheiten in Simulationsmodellen genutzt en Techniken, sind entweder rechenaufwändig (Monte Carlo [MC] -basierte Methoden) oder liefern Ergebnisse von heterogener Qualität (Gauß-Quadraturen [GQs]). In Anbetracht der Bedeutung von effizienten Methoden zur Quantifizierung von Unsicherheit im Zeitalter von „big data“ ist es das Ziel dieser Doktorthesis, Methoden zu entwickeln, die die Näherungsfehler von GQs verringern und diese Methoden einer breiteren Forschungsgemeinschaft zugänglich machen. Zu diesem Zweck werden zwei neuartige Methoden zur Quantifizierung von Unsicherheiten entwickelt und in vier verschiedene, große partielle und allgemeine Gleichgewichtsmodelle integriert, die sich mit Agrarumweltfragen befassen. Diese Arbeit liefert methodische Entwicklungen und ist von hoher Relevanz für angewandte Simulationsmodellierer. Obwohl die Methoden in großen Simulationsmodellen für Agrarumweltfragen entwickelt und getestet werden, sind sie nicht durch Modelltyp oder Anwendungsgebiet beschränkt, sondern können ebenso in anderen Zusammenhängen angewandt werden. / Simulation models are an established tool for assessing the impacts of exogenous shocks in complex systems. Recent increases in available computational power and speed have led to simulation models with increased levels of detail and complexity. However, this trend has raised concerns regarding the uncertainty of such model results and therefore motivated many users of simulation models to consider uncertainty in their simulations. One way is to integrate stochastic elements into the model equations, thus turning the model into a problem of (multiple) numerical integration. As, in most cases, such problems do not have analytical solutions, numerical approximation methods are applied. The uncertainty quantification techniques currently used in simulation models are either computational expensive (Monte Carlo [MC]-based methods) or produce results of varying quality (Gaussian quadratures [GQs]). Considering the importance of efficient uncertainty quantification methods in the era of big data, this thesis aims to develop methods that decrease the approximation errors of GQs and make these methods accessible to the wider research community. For this purpose, two novel uncertainty quantification methods are developed and integrated into four different large-scale partial and general equilibrium models addressing agro-environmental issues. This thesis provides method developments and is of high relevance for applied simulation modelers who struggle to apply computationally burdensome stochastic modeling methods. Although the methods are developed and tested in large-scale simulation models addressing agricultural issues, they are not restricted to a model type or field of application.

Die Dissertation befasst sich mit der Erweiterung und Anwendung des allgemeinen räumlichen Gleichgewicht- und Transportmodells RELU-TRAN (Anas und Liu, 2007) und analysiert verschiedene verkehrs- und klimabezogene Politikmaßnahmen (Tempo-30 in Städten, Infrastrukturqualität, Anpassung an den Klimawandel) in einer Stadtökonomie.