Cette thèse en essais propose une analyse des conséquences de différentes règlementations environnementales sur la croissance et le bien-être des agents économiques. Nous considérons trois instruments de régulation, correspondant à nos trois chapitres: les accords volontaires, les taxes pigouviennes et l'utilisation jointe taxe-subvention.Le premier thème de travail s'intéresse à la profitabilité de différents types d'accords volontaires visant à réduire la production d'un bien non-efficient en utilisation d'énergie. Nous définissons un accord volontaire optimal pour la société et analysons les effets de cet accord sur le marché de l'énergie. Notre conclusion est que l'accord entraîne une baisse de la quantité d'énergie d'équilibre et du prix. Cependant, un effet de détournement estimé à 30% se produit.Le deuxième thème de travail valide l'hypothèse de Porter, selon laquelle une règlementation environnementale stricte mais bien pensée peut engendrer des bénéfices sociaux et des bénéfices privés pour les firmes qui y sont soumises. Plus précisément, nous analysons les effets de l'instauration de différentes taxes environnementales dans le contexte particulier d'un lac superficiel. Nous montrons que l'instauration d'une taxe peut amener les agents économiques à converger vers un état stationnaire supérieur au sens de Pareto.Le troisième thème de travail s'attaque au paradoxe vert, qui énonce que les politiques de lutte contre le changement climatique peuvent provoquer, au contraire de leur objectif, une accélération du phénomène de réchauffement. Nous utilisons un modèle de ressources, combinant une ressource exhaustive, dont l'utilisation engendre des émissions polluantes et une ressource renouvelable, non polluante. L'équilibre sur le marché de l'énergie définit un temps d'arrêt endogène de la production de l'énergie sale, si le stock initial de cette énergie est faible. Si ce stock initial est important, l'économie converge vers un état stationnaire où la quantité produite d'énergie polluante est nulle. L'introduction d'une taxe sur l'énergie sale et d'une subvention à l'énergie propre entraîne une prolongation du régime d'utilisation jointe des deux énergies. A tout instant, la quantité d'énergie exhaustive consommée (et donc la pollution) diminue avec la règlementation environnementale. Nous réfutons le paradoxe vert. / This essay thesis proposes an analysis of the consequences of different environmental regulations on growth and on the economic agents' welfare. We consider three instruments of regulation, corresponding to our three chapters: voluntary agreements, pigovian taxes, and the joint use of tax and subsidy.The first work theme is devoted to the profitability of different voluntary agreement types, the aim of which is to reduce the production of the good which is not efficient in terms of energy use. We define a voluntary agreement optimal for society and analyse its effects on the energy market. Our conclusion is that the agreement leads to a decrease of the energy quantity and of the price. However an estimated leakage effect of 30% is likely to occur.The second work theme validates the Porter Hypothesis, in which a strict and well-thinking regulation can produce social benefits and private benefits for firms which are subject to the regulation. More precisely, we analyse the effects of the set up of different environmental taxes in the particular context of a shallow lake. We show that a tax set up can make the economic agents converge to a Pareto-superior steady state.The third work theme is concerned with the green paradox, which states that policies against global warming can cause an acceleration of the rise phenomenon, contrary to their objective. We use a resource model combining an exhaustible resource which creates polluting emissions, and a renewable, non-polluting, resource. The energy market equilibrium defines an endogenous stopping time of the dirty energy's production, if the initial stock of this energy is relatively weak. If this initial stock is high, the economy converges to a steady state in which the consumed quantity of polluting energy is null. The introduction of a tax on polluting energy and of a subsidy on clean energy leads to a prolongation of the joint use's system. At any time, the consumed quantity of polluting energy (and so the pollution) decreases with the environmental regulation. We refute the green paradox.

The diploma thesis topic is Voluntary agreements in the environment problems and advantages. The theoretical part describes how the attitude to the environment was developing, from the restrictive regulations to the first voluntary attitudes. The part of the thesis is devoted to the problems of the environment´s valuation because one of the tasks of the voluntary agreements is the effort to internalize externalities. For this the valuation of the environment is needed, which is problematic. At first the voluntary attitudes to the environmental protection are described in general and there are voluntary agreements that are described more in detail. The practical part is devoted to the problems of voluntary agreements in the Czech Republic. All voluntary agreements made in the Czech Republic are described. These particular agreements are assessed according to their results whether they fulfilled their purpose because of which they had been made. The component of the practical part is also a questionnaire which was to be filled in by companies which have been using some voluntary attitude, e.g. EMAS, ecolabeling or some voluntary agreement. In the conclusion the attitude of The Ministry of the Environment to the voluntary agreements is assessed as well as the effect of the voluntary agreements in the Czech Republic itself.

Ungefär en tredjedel av all mat som produceras runt om i världen går förlorad eller slängs, vilket resulterar i negativ påverkan på klimat och miljö, ekonomiska förluster samt bortfall av mat som annars kunnat tillgodose människor med mat. Att förebygga matsvinn har således flera positiva synergieffekter, men det behövs mer kunskap om orsaker till varför det uppstår samt ett fortsatt arbete för att företag, myndigheter och organisationer gemensamt ska kunna arbeta med svinnproblematiken. Ett aktivt samarbete mellan aktörer i livsmedelskedjan har internationellt och nationellt lyfts som viktiga förutsättningar för att kunna minska matsvinnet. I Sverige startades i fjol den frivilliga överenskommelsen Samarbete för minskat matsvinn (SAMS). Detta examensarbete ämnar att kartlägga var matsvinnet uppkommer i värdekedjor för två livsmedel, nötkött och potatis, samt identifiera orsaker till varför det uppstår. Vidare syftar rapporten till att bistå SAMS i sitt fortsatta arbete för att minska matsvinn genom att identifiera möjliga förebyggande åtgärder till de identifierade orsakerna. Tillvägagångssättet bestod av fyra huvuddelar: kartläggning av värdekedjan och dess förluster, hotspot-analys för att identifiera orsaker som SAMS kan påverka och som bidrar till stora mängder svinn, rotorsaksanalys för att identifiera rotorsaker och till sist lösningsplanering för att föreslå förebyggande åtgärder. Arbetet genomfördes via en systematisk litteraturstudie, semistrukturerade intervjuer med aktörer i livsmedelskedjan samt workshop-tillfällen med SAMS-medlemmar.  Resultaten visar att flertalet orsaker uppstår i minst två av leden i värdekedjorna och att orsaker kopplade till nötkött och potatis inom primärproduktionen och industrin skiljer sig från varandra. Samtidigt har orsaker kopplade till de senare leden av värdekedjorna från grossist och framåt mer liknande karaktär, som till exempel utgånget hållbarhetsdatum. Av de kartlagda orsakerna gjordes en bedömning kring orsaker som har stor påverkan samt orsaker som kan påverkas av ett samarbete mellan aktörer, vilket resulterade i hotspot-orsaker. För både nötkött och potatis erhölls 17 hotspot- orsaker som analyserades vidare i en rotorsaksanalys med hjälp av fiskbensdiagram. Utifrån fiskbensdiagrammen och vilka orsaker som var vanligt förekommande under arbetets gång applicerades fem-varför-metoden på orsaker kopplade till utgånget hållbarhetsdatum. Sju rotorsaker identifierades vilka berör avtal, förpackningar, riktlinjer, förvaring, kundpreferenser och beställningar. Lösningsförslagen adresserar förändrade avtal och förpackningar, underlättning av nedfrysningsmöjligheter, medvetandegörande av konsument, samt förändrad förvaring i butik och beställningsrutiner. Det visade sig att många rotorsaker grundar sig i flera hotspot-orsaker vilket indikerar att åtgärderna som föreslås har potential att förebygga fler hotspot-orsaker än utgånget hållbarhetsdatum. / Nearly one third of food produced for human consumption is lost or wasted globally, which results in negative impact on the environment and climate, economic losses and people who are undernourished. Therefore, preventing food losses and food waste has several positive synergy effects. However more knowledge is needed regarding the causes of losses and waste as well as continued work for companies, authorities and organizations to be able to work effectively with the waste problem. Active cooperation between stakeholders in the food supply chain has proven to be one of four important prerequisites for successful work to reduce food waste. In Sweden, a voluntary agreement called Samarbete för minskat matsvinn, SAMS was initiated last year. This thesis aims to map where food losses and waste arise in the value chain of two products, beef and potatoes, and to identify causes why it occurs. Furthermore, the report aims to contribute to SAMS in their continued work to reduce food losses and waste by identifying opportunities to prevent the identified causes. The aim is answered through an approach that consists of four parts: mapping the value chain and its losses, hotspot analysis to identify causes SAMS can impact and that contribute to the most wastage, root cause analysis to get down to the root causes and lastly solution generation to propose preventive measures. The study was carried out through extensive literature review and interviews, as well as workshops.  The results show that most causes occur in at least two of the links in the value chain, whereas the causes for beef and potatoes differ within the primary production and industries. Meanwhile, causes within retailers and forward towards the value chain are of similar characteristics. Of the identified causes, an assessment was made of which have a major impact and can be improved by SAMS, resulting in hotspot causes. For both beef and potatoes, 17 causes were obtained which were further analyzed in root case analysis using fishbone diagrams. Based on the fishbone diagrams and often occured causes during the work process, the five-why method was applied to causes correlated to expiration date. Seven root causes were identified which are related to contracts, packaging, guidelines, storage, customer preferences, and orders. Solution proposals presented to the root causes encompass contract changes, packaging solutions, freezing options, changing consumers’ behaviors, storage opportunities and different ordering routines. It showed that many root causes are based on several hotspot causes, which indicates that the proposed solutions have potential to prevent several causes than only passed expiration date.