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Operations Management / (M.Sc.(Operation Research))

This thesis consists of three papers which contribute to the literatures on regulation and organizational economics.<p><p><p>The first part of the dissertation addresses questions related to the procurement decisions of private and public organizations. In particular it focuses on how the anticipation of renegotiating the contractual terms during the execution of a procurement contract affects the initial arrangements between the parties. Renegotiation may involve the design itself of the goods which are procured, and not just their price or the time of their delivery. A plausible explanation for its pervasiveness is the existence of transaction costs which prevents contracts from being complete. This is especially true for more sophisticated and customized goods, such as new infrastructures or cars' and aircrafts' parts or components. Ex-post these goods may fail to fit the buyer's specific needs and/or may exhibit flaws unforeseen at the planning stage.<p><p><p>In the first two chapters, I show that the anticipation of ex-post adaptations has critical implications for many procurement choices, such as that of the contractual agreement, the award mechanism, and the delegation of the design task to the suppliers. Therefore, a proper inclusion of design failures into the analysis of procurement contracts can help broaden our understanding of the wide variety of procurement modes and outcomes observed in the real world. My analysis offers an explanation for the procurement practices adopted in complex manufacturing and construction industries. Moreover, it can provide useful guidance for public procurement. Governments face tight restrictions in their choices of the procurement modes and for this reason they should carefully evaluate whether or not to adopt the best practices of the private sector.<p><p><p>The second part of the dissertation concerns the optimal design of an organization. In many organizations the task of evaluating an agent's performance is delegated to a third party, a supervisor, who can opportunistically misreport information. The question of how the provision of incentives in hierarchies is affected by the supervisor's opportunism is of great importance since it can improve our understanding of the internal organization of firms and can have broad applications to regulatory design.<p><p><p>The third chapter of the thesis, co-authored with Luca Livio (ECARES, FNRS), contributes to this line of research by studying the optimal task a supervisor should be charged with in the presence of corruption concerns. We highlight the existence of a trade-off between monitoring the agent's effort choice and auditing it ex-post, which arises when the two faces of corruption, collusion and extortion, are present. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

In this thesis we define and study the existence of an equilibrium situation in which producers maximize their profits relative to the production vectors in their production sets, consumers satisfy their preferences in their consumption sets under certain budget constraint, and for every commodity total demand equals total supply. This competitive equilibrium situation is referred to as the Walrasian equilibrium. The existence of this equilibrium is investigated from a various mathematical points of view. These include microeconomic theory, simplicial spaces, global analysis and lattice theory.

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The interaction of theoretical computer science with game theory and economics has resulted in the emergence of two very interesting research directions. First, it has provided a new model for algorithm design, which is to optimize in the presence of strategic behavior. Second, it has prompted us to consider the computational aspects of various solution concepts from game theory, economics and auction design which have traditionally been considered mainly in a non-constructive manner. In this thesis we present progress along both these directions. We first consider optimization problems that arise in the design of combinatorial auctions. We provide an online algorithm in the important case of budget-bounded utilities. This model is motivated by the recent development of the business of online auctions of search engine advertisements. Our algorithm achieves a factor of $1-1/e$, via a new linear programming based technique to determine optimal tradeoffs between bids and budgets. We also provide lower bounds in terms of hardness of approximation in more general submodular settings, via a PCP-based reduction. Second, we consider truth-revelation in auctions, and provide an equivalence theorem between two notions of strategy-proofness in randomized auctions of digital goods. Last, we consider the problem of computing an approximate Nash equilibrium in multi-player general-sum games, for which we provide the first subexponential time algorithm.

This dissertation consists of three independent essays. We briefly introduce these essays in chapter 1 and leave a comprehensive introduction to each essay. Chapter 2 considers a vertically separated industry where production takes time and vertical mergers shorten production time. We investigate the impact of vertical mergers on the downstream firms' ability to collude and show that vertical mergers facilitate downstream collusion. Chapter 3 provides a theoretical foundation for a puzzling empirical observation that advertising follows an inverted U shape for some new products. Chapter 4 analyzes an incumbent's response to a competitive entry. We show that if the quality of the entrant is uncertain, the incumbent can "jam" the quality signalling of the entrant. Finally, chapter 5 summarizes main conclusions of three essays. / text

[Truncated abstract] The core objective of this thesis is summarised by its title: “Understanding the World Wool Market: Trade, Productivity and Grower Incomes”. Thus, we wish to aid understanding of the economic mechanisms by which the world wool market operates. In doing so, we analyse two issues trade and productivity and their effect on, inter alia, grower incomes. To achieve the objective, we develop a novel analytical framework, or model. The model combines two long and rich modelling traditions: the partial-equilibrium commodity-specific approach and the computable-general-equilibrium approach. The result is a model that represents the world wool market in detail, tracking the production of greasy wool through five off-farm production stages ending in the production of wool garments. Capturing the multistage nature of the wool production system is a key pillar in this part of the model . . . The estimated welfare gain for China is 0.1% of real income; this is a significant welfare gain. For three losing regions Italy, Germany and Japan the results are robust and we can be highly confident that these regions are the largest losers from the complete removal of 2005 wool tariffs. In both wool tariff liberalisation scenarios, regions whose exports are skewed towards wool textiles and garments gain the most as it is these wool products that have the highest initial tariff rates. The overall finding of this work is that a sophisticated analytical framework is necessary for analysing productivity and trade issues in the world wool market. Only a model of this kind can appropriately handle the degree of complexity of interactions between members (domestic and foreign) of the multistage wool production system. Further, including the nonwool economy in the analytical framework allows us to capture the indirect effects of changes in the world wool market and also the effects on the nonwool economy itself.

This study seeks to investigate the trends and interactions of market volatility as a source of instability in the South African financial markets. Financial instability can be manifested in the form of banking and currency crisis, institutional failures and extreme asset price volatility. This study, however, focuses on a single aspect of financial instability - asset price volatility. Asset price volatility reflects changes in market expectations as investors react to such changes, and thus on its own is not necessarily a source of instability. However, volatility spillovers can propagate volatility shocks across the market, increasing the risk of widespread instability. Using a combination of graphical and trend analysis as well as more formal estimation techniques, the study examined volatility in the stock, money and foreign exchange markets. To obtain estimates of market volatility, the study experimented with various volatility models that include the GARCH, TARCH and EGARCH. An analysis of volatility interactions and the transmission of volatility shocks across the market is crucial to understanding financial instability. To examine volatility interaction and the transmission of volatility shocks, a VAR model was estimated. This framework allowed us to examine the propagation of shocks across the markets. Volatility in the financial markets was found to be highly persistent and in the case of exchange rates, volatility was also characterised by an increasing trend. Significant linkages between the financial markets were found. The links also extended to the volatility relationship as evidenced by significant volatility spillovers across the markets. While volatility spillovers from the money market were found in the stock market and the foreign exchange market, no volatility spillovers from these markets were found in the money market. Thus the money market was identified as the major source of volatility spillovers and shocks in the financial markets. These results highlighted the role of monetary policy in the financial system, specifically the need to make monetary policy stable and predictable to ensure that interest rate shocks are not an additional source of instability. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in