This thesis characterizes how a mergers profitability and efficiency are affected by its size and by its scale economy factor d in a Cournot market with linear demand and quadratic costs. Our results allow us to challenge the widely believed view among economists that mergers typically are not profitable for the insiders (merged firms). In contrast to the minimum of 80% pre-merger market share required for the insiders to be profitable in Salant, Switzer and Reynolds (1983), our model shows that mergers with much less market share are also profitable. It is worth noting that in the market with diseconomies of scale (i.e., d>0), any two-firm merger could be profitable as long as its scale economy factor is greater than the critical value which is solely determined by the market size n. Our results also allow us to provide useful implications for antitrust laws especially the horizontal merger policy. In our model, mergers with economies of scale (i.e., d>-2 and d<0) and with more than 50% combined pre-merger market share are beneficial to both public interest and merging firms. This observation implies that even monopolies in this market could contribute positively to social welfare. This result is different from what Farrell and Shapiro (1990) and Levin (1990) have obtained in their papers that only mergers with less than 50% pre-merger market share are both profitable and efficient. Although mergers generally raise price, we find that mergers can also lower price and expand output if and only if they enjoy substantial economies of scale.

This thesis characterizes how a mergers profitability and efficiency are affected by its size and by its scale economy factor d in a Cournot market with linear demand and quadratic costs. Our results allow us to challenge the widely believed view among economists that mergers typically are not profitable for the insiders (merged firms). In contrast to the minimum of 80% pre-merger market share required for the insiders to be profitable in Salant, Switzer and Reynolds (1983), our model shows that mergers with much less market share are also profitable. It is worth noting that in the market with diseconomies of scale (i.e., d>0), any two-firm merger could be profitable as long as its scale economy factor is greater than the critical value which is solely determined by the market size n. Our results also allow us to provide useful implications for antitrust laws especially the horizontal merger policy. In our model, mergers with economies of scale (i.e., d>-2 and d<0) and with more than 50% combined pre-merger market share are beneficial to both public interest and merging firms. This observation implies that even monopolies in this market could contribute positively to social welfare. This result is different from what Farrell and Shapiro (1990) and Levin (1990) have obtained in their papers that only mergers with less than 50% pre-merger market share are both profitable and efficient. Although mergers generally raise price, we find that mergers can also lower price and expand output if and only if they enjoy substantial economies of scale.

There are three main chapters in the dissertation which fall in the areas of industrial organization and international economics. After the introduction and the literature review, I present two different models that highlight how the degree of substitutability between differentiated products on a market affects a new entrant's entry decisions. I further extend the benchmark model to discuss the implications of the government trade policy on the competition strategies. The last chapter investigates how the bilateral trade flows in various industries between the United States and China respond to Yuan/Dollar exchange rate fluctuations and a few other key variables. In the second chapter, I extend the Singh and Vivies (1984) model and the Hackner (2000) model by allowing for a multi-product duopoly, a domestic incumbent and a foreign entrant, with asymmetric costs in producing two differentiated products: high- and low-quality. If they engage in Cournot competition, in the subgame perfect Nash equilibrium, the foreign entrant will choose to supply both products when two varieties are more heterogeneous. If two varieties are more homogeneous, the foreign entrant tends to supply only one product. After extending the model to consider the tariff imposed on foreign imports, the simulation results suggest that, to increase domestic welfare, the government should allow cost-effective foreign entrants to enter, but keep cost-ineffective ones out of the domestic market. In the third chapter, I provide a thorough analysis of the Bertrand model with a setup that is similar to the Cournot model. When firms compete on prices, the SPNE differs significantly from that of the Cournot model. Depending on the relative marginal cost between two firms, there are circumstances under which the foreign entrant would choose to only enter into the low- or the high-quality market regardless of the degree of substitutability between two varieties. Furthermore, when the domestic government imposes a tariff on the foreign imports, the foreign entrant's entry decision changes with the tariff level. In the last chapter, unlike the existing literature which mainly look at the relationship between the exchange rate and the trade balance at the aggregate level, I attempt to investigate the short-run and the long-run impact of the Yuan/Dollar exchange rate on the US trade balance at the commodity level using a new methodology, the Autoregressive Distributed Lag Bounds Testing approach. As most articles found no short-run and long-run relationship between the exchange rate and the trade balance at the aggregate level ("aggregation bias"), I argue that different commodities may respond to the exchange rate fluctuations differently. Therefore, this study would offer us a better understanding on which US industries are more vulnerable to the Yuan/Dollar exchange rate fluctuations and which ones are strong players against Chinese competitors. In addition, I further explore other possible contributors to the US trade deficit such as income levels, China FDI inflow, and the US FDI outflow. / Economics

This diploma thesis deals with conict economic situations based on game theory. In the beginning, basic models of conict situations and current popular software tools are dened not only for the general support of student education or for science, but also for solving economic problems in game theory. Based on this analysis, the conicting situation of two competing rms is being solved. Gradually, work goes deeper into areas of delay dierential equations that better show the behavior of two players on the market. Subsequently, these delayed dierential equations are projected into the Cournot model, for which a critical value is identied that switches the stability of two rms on the market due to the delayed realization of their outputs.

This Master’s thesis deals with the application of cooperative game theory for solving the problems of Cournot's oligopolies. The knowledge of oligopoly theory and game theory has been elaborated to build a model describing the behavior of companies at a market that meets the preconditions of Cournot's oligopoly. The definition of cooperative game is based on the -characteristic function, which takes into account, compared to classical methods, that companies which are not in the coalition are pursuing their own profits, not suppressing coalition positions. The properties of the resulting cooperative games are examined in detail, focusing on monotony and convexity. Several theorems about these properties have been derived and their economic interpretations are given. Also, the question of calculation of the -characteristic function using the best-reply dynamics algorithm is being solved, and its convergence for a given type of games is justified. The model is applied to data from the oil market, which is further characterized by the results of the cooperative game.

This dissertation seeks to contribute to the policy discussion on how to design efficient and sustainable energy policies. In three self-contained chapters, it applies microeconomic theory and empirical analysis to identify three market failures in European energy markets and to evaluate specific policy measures that strive to overcome these failures in order to increase market efficiency and to enhance environmental or societal sustainability. Chapter 1 and 2 study European electricity markets, which play an important role in the transition towards a carbon-neutral energy future. Overcoming barriers to efficient electricity markets is a crucial step to keep the costs of this transition as low as possible to society. Both chapters focus on obstacles to electricity market efficiency that have recently been highlighted by the European Commission. On the supply side, subsidies for renewable electricity may distort production incentives and competition in wholesale electricity markets. Chapter 1 applies a theoretical model to study the effect of different subsidies on producer strategies and competition in wholesale electricity markets. On the demand side, the European Commission seeks to overcome the reluctance of residential electricity consumers to switch electricity supplier in order to ensure effective competition in the retail electricity market. Chapter 2 empirically quantifies different reasons for switching inertia using a structural discrete choice model and performs counterfactual analysis to study the effect of different policy measures that seek to overcome switching inertia. Chapter 3 looks at the building sector, which accounts for 40% of final energy consumption in Europe and is a major emitter of carbon emissions. In the residential housing market information asymmetries hamper incentives to invest in energy efficiency improvements of rental property. This chapter empirically analyzes the effect of a European policy that mandates the use of energy performance certificates aiming at establishing an efficient market for energy efficient dwellings. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished