In their famous paper on the "Big Push", Murphy, Shleifer, and Vishny (1989) show how the combination of increasing returns to scale at the firm level and pecuniary externalities can give rise to a poverty trap, thereby formalising an old idea due to Rosenstein-Rodan (1943). We develop in this paper an oligopoly model of the Big Push that is very close in spirit to the Murphy-Shleifer-Vishny (MSV) model, but in contrast to the MSV model it is easily extended to the case of an economy that is open to international trade. Having a workable open-economy framework allows us to address the question whether globalisation makes it easier or harder for a country to escape from a poverty trap. Our model gives a definite answer to this question: Globalisation makes it harder to escape from a poverty trap since the adoption of the modern technology at the firm level is impeded by tougher competition in the open economy.

Cloud computing has become a cornerstone of the modern digital economy, with Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) leading the market. This thesis explores the oligopolistic tendencies and lock-in effects in the cloud computing market. It examines how strategic pricing and market behaviors by these major providers influence competitive dynamics and industry structure using established economic models like Cournot and Stackelberg. The research integrates theoretical analysis with an empirical case study of Ericsson's cloud service adoption, highlighting how theoretical pricing strategies are applied in practice. Ericsson's case study revealed that AWS is the most cost-effective for pay-as-you-go pricing, while Azure offers lower costs for reserved and spot pricing models. The study also indicates that the market is highly concentrated, as shown by the Three-Firm Concentration Ratio and the Herfindahl-Hirschman Index, suggesting a decrease in competition over time. A significant finding of this study is the strong lock-in effect experienced by customers due to high switching costs, including data migration, retraining, and system reconfigurations. These costs effectively discourage customers from switching providers, reinforcing the dominant positions of the leading cloud service providers.  The findings reveal how market leaders strategically react to competition and influence market structure. This study provides valuable insights for businesses and policymakers on fostering a competitive environment that encourages innovation and fair pricing practices. It contributes to understanding the complexities of market dynamics, the strategic decision-making process, and the significant impact of vendor lock-in in oligopolistic markets. / Molntjänster har blivit en hörnsten i den moderna digitala ekonomin, med Amazon Web Services (AWS), Microsoft Azure och Google Cloud Platform (GCP) som marknadsledare. Denna avhandling undersöker de oligopolistiska tendenserna och inlåsningseffekterna på molntjänstmarknaden. Den undersöker hur strategisk prissättning och marknadsbeteenden hos dessa stora leverantörer påverkar konkurrensdynamik och branschstruktur med hjälp av etablerade ekonomiska modeller som Cournot och Stackelberg. Forskningen integrerar teoretisk analys med en empirisk fallstudie av Ericssons adoption av molntjänster, vilket belyser hur teoretiska prissättningsstrategier tillämpas i praktiken. Ericssons fallstudie visade att AWS är mest kostnadseffektivt för betala-efter-användning prissättning, medan Azure erbjuder lägre kostnader för reserverade och spot prissättningsmodeller. Studien indikerar också att marknaden är starkt koncentrerad, vilket framgår av analysen av Three-Firm Concentration Ratio och Herfindahl-Hirschman Index, som antyder en minskning av konkurrensen över tid. En betydande upptäckt i denna studie är den starka inlåsningseffekt som kunder upplever på grund av höga omställningskostnader, inklusive datamigrering, omskolning och systemomkonfigurationer. Dessa kostnader avskräcker effektivt kunder från att byta leverantörer, vilket förstärker de ledande molntjänstleverantörernas dominerande positioner. Resultaten visar hur marknadsledarna strategiskt reagerar på konkurrens och påverkar marknadsstrukturen. Denna studie ger värdefulla insikter för företag och beslutsfattare om att främja en konkurrensutsatt miljö som uppmuntrar innovation och rättvis prissättning. Den bidrar till förståelsen av marknadsdynamikens komplexitet, den strategiska beslutsprocessen och den betydande påverkan som leverantörsinlåsning har i oligopolistiska marknader.

Cette thèse couvre deux sujets : le dessin des permis à polluer et la gestion des déchets. Le premier chapitre analyse la mise en œuvre des permis à polluer. Le chapitre se concentre sur les impacts de la distribution liés à la sévérité de l’allocation gratuite basée sur la production courante quand deux secteurs sont couverts par le marché des permis et le plafond reste constant. Un nouveau type d’augmentation des profits dans les secteurs qui ne sont pas exposés à la concurrence internationale a été démontré théoriquement. Le deuxième chapitre traite la question de la différenciation de l’allocation des permis dans les différentes régions, liée à la possibilité des entreprises à délocaliser. Les conditions dans lesquelles le bien-être décroît avec la délocalisation sont déterminées. Dans ce cas, des distributions gratuites de permis peuvent être utilisées pour éviter la délocalisation des entreprises. Le troisième chapitre compare l’efficacité des programmes de la responsabilité élargie du producteur (REP) avec l’efficacité d’une ex-ante taxe. La taxe permet plus de flexibilité ex-ante quant aux conditions du marché, mais la REP permet plus d’adaptation ex-post aux réalisations des coûts. Ainsi, l’efficacité relative de la REP augmente avec l’incertitude des coûts et la compétitivité du marché. / This thesis covers two subjects. One is the design of pollution permits and the other is the waste management. The first chapter analyses the implementation of pollution permits. It focuses on the distributional impacts linked with the stringency of output-based allocation,when two sectors are covered by the market for permits and the total cap is held constant. Theoretically demonstrated is a new type of profit increase in sectors that are not exposed to international competition. The second chapter addresses the issue of differentiating permit allocation across areas, this being linked to the possibility of firms to relocate. The conditions under which welfare decreases with relocation are determined. In such a case, free allowances may be used to prevent firms from relocating. The third chapter compares the efficiency of extended producer responsibility (EPR) programs and the efficiency of an ex-ante tax. The tax allows more ex-ante flexibility regarding market conditions, but the EPR allows more ex-post adaption to cost realizations. As a result, the relative efficiency of the EPR increases with uncertainty of the costs and competitiveness of the market.