This work deals with legal aspects of collective dominant position under Article 82 of the Treaty establishing European Community (hereinafter- EC). The purpose is to reveal a legal definition and main features of collective dominant position. The author examines features and criteria which are established in the jurisprudence of EC institutions. The author examines features and criteria which are established in the jurisprudence of EC institutions. The author also indicates that the criteria for establishing collective dominance are not fully scrutinized under EC competition law. Moreover, the practice of EC institutions is analyzed not only under Article 82, which prohibits abuse of a dominant position, but also under Merger regulation to that extent which is necessary to reveal the main topic. Further the work presents problems which are found under these two institutions of EC competition law.

The aim of the diploma thesis is a comprehensive analysis of the concept of collective dominance, in particular with reference to the evaluation of its applicability and utility in practice. The first chapter deals with the main features of the oligopoly market and Czech and European legal provisions on the abuse of a dominant position and mergers within which it has evolved. On base of the analysis of Court of Justice and General Court judgements the second chapter explains the notion of the collective dominance and examines the obligatory conditions of the collective dominance, as well as the factors which influence these conditions. The third chapter concerns the concept of collective dominance with regard to competition law taxonomy. It compares not only the test of collective dominance applied pursuant to the article 102 TFEU with the test applied according to the Council Regulation (EC) No 139/2004 on the control of concentrations between undertakings, but also the concept of collective dominance with the agreements pursuant to the article 101 TFEU. It also deals with abusive practices typical for oligopolies. Beside the explanation of the UK legislation the last two chapters illustrate decisions of competition authorities in the Czech Republic and in the United Kingdom and analyse and compare them. The diploma thesis is concluded by the analysis of main shortcomings of the concept of collective dominance and the evaluation of actual state of the examined topic with the aim to abstractly summarize knowledge gained through the thesis.

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.