Auctions have a long history and are an effective method to distributed resources. In the era of Internet and e-commerce, electronic sealed-bid auction play an important role in business. However, it is a risk to run a sealed-bid auction through the Internet, which is an open and unreliable environment. There are many security concerns about correctness and fairness of the auction and privacy of the bidders in electronic sealed-bid auctions. Cryptology seems to be the only security solution for electronic sealed-bid auction. On the other hand, a practical electronic sealed-bid auction scheme must be efficient. So efficient application of cryptographic tools to electronic sealed-bid auction is the focus of this thesis. Firstly, security requirements of sealed-bid auctions are surveyed. The auction result must be determined correctly according to the submitted bids and the pre-defined auction rule. The bidders must compete with each other in a fair play and none of them can take advantage of others. The auction must be publicly verifiable, so that the auction result is acceptable by everyone. Usually, a losing bidder hopes to keep his bid secret, so the losing bids should be kept secret. In different applications, different auction rules may be applied. So, to avoid a tie, a large number of biddable prices must be accepted in some applications. Secondly, the currently known sealed-bid auction schemes are classified. In recent years, many sealed-bid auction schemes based on various cryptographic primitives have been proposed. Nearly all of them can be classified into five models. In the Model 1, each bid is known to the auctioneers, who can find the winning bid and winner very efficiently. Bid privacy is not implemented in Model 1. In Model 2 homomorphic bid opening is employed, so that the winning bid and winner can be found while the losing bids are kept secret. In Model 3 very strong bid privacy is achieved through a Dutch-style bid opening, which is highly inefficient. In Model 4, the link between the bids and bidders instead of confidentiality of the bids is kept secret. This kind of confidentiality is weaker than normal bid privacy and called relative bid privacy in this thesis. (Complete confidentiality of the bids in the end of the auction is called absolute bid privacy.) Implementation of relative bid privacy can be very efficient if an efficient anonymous channel can be constructed. Model 5 uses secure evaluation to open the bids and find the auction result and makes it possible to achieve absolute bid privacy efficiently. Three main cryptographic primitives are explored and employed to design new auction schemes in four auction models. The first tool is batch verification, which can improve computational efficiency in auction schemes. The second is mix network, which can be used to implement anonymous channels in Model 4 and Model 5. Two new efficient mix networks are designed and used in Model 2, Model 4 and Model 5. The third is secure evaluation, which is employed in two new auction schemes in Model 5 to achieve strong bid privacy efficiently. Other cryptographic primitives employed in the auction schemes include efficient 1-out-of-w oblivious transfer in Model 2 and key chain in Model 3. Five new auction schemes are proposed. The first scheme in Model 2 batch verifies bid validity to improve efficiency. The second scheme optimises the key chain used in Model 3 to obtain a more advanced auction scheme. The third scheme implements a concrete anonymous channel in Model 4 for the first time and achieves relative bid privacy and high efficiency convincingly. The last two employ new secure evaluation techniques to achieve absolute bid privacy and high efficiency. With these five new auction schemes, better solutions are achieved in various auction applications.

This thesis explores factors that determine the price for Australian art sold at auction. Using a large data set that comprises over 20,000 sale observations of Australian paintings sold between 1995 and 2003 characteristics associated with the artist, the work and auction are included in a series of hedonic models. In addition to modelling the overall market, differences within defined market segments for Indigenous and Non-indigenous art are explored. The role of artist identity and critical acclaim, the period in which art works are created and the event of an artist death are areas of specific focus within the analysis along with an investigation of the risks and returns associated with Australian art investment. It is found that artist identity is a crucial factor that drives price. Further, the most highly valued Non-indigenous art works are found to be created prior to 1900, although the market for Contemporary art produced post 1980 is associated with relatively high prices also. Distinctions emerge between Indigenous and Non-indigenous art as we consider the period in which works are created and the influence this has upon price. Almost 90 per cent of Indigenous art sold at auction has been created since 1970 and it is works from the 1970s that command the highest prices for Indigenous art sold at auction. This is not unexpected given the rise of Indigenous art in the early 1970s coinciding with the emergence of the Papunya Tula art movement. The death of an artist also proves to have a different influence upon price when we compared Indigenous and Non-indigenous art. For Non-indigenous art there is clear evidence of a death effect upon art prices, where prices typically rise around the time of an artists death before falling back somewhat with the passing of time. For Indigenous art the influence of a living artist's conditional life expectancy upon price proves to be of greater relevance in explaining price where as the artist ages and the term of their life expectancy reduces prices tend to rise. The analysis within this thesis finishes with the construction of a number of short term art price indices where it is found that returns to investment in Indigenous art are generally higher and less risky compared to Non-indigenous art. Australian art generally and Indigenous art in particular is found to have a relatively weak correlation with the stock market suggesting that Australian art has a role to play in a balanced investment portfolio especially taking into account the aesthetic utility that can also be derived as a result of holding art. The research contributes to understanding how the auction market for Australian art operates with emphasis paid to the distinctions and similarities observed within the sub-markets for Indigenous and Non-indigenous art. Insights from this research have the potential to inform public policy on a number of issues including the effect of resale royalties upon the operation of the auction market, and how indigenous economic development may be facilitated through a strong market for Indigenous art.

This article describes the creation and operation of a market that has been functioning since very recently in the country. It shows the stages for the implementation of this market, which begins with bilateral agreements to sell natural gas and transportation capacity between the actors involved, and later gives way to day-to-day electronic auctions. Additionally, this article shows the main contractual provisions which are often incorporated into bilateral agreements for the transference of transportation capacity. Finally, two important deficiencies that appeared in these years of operation will be analyzed, such as the restrictionon the transference of volumes of natural gas, and the exclusion from this market of capacity surpluses of the service of distribution of natural gas through pipelines that is contracted by consumers. / El presente artículo describe la creación y funcionamiento de un mercado que viene funcionando hace muy poco tiempo en el país. A través de este artículo se podrá conocer las etapas para la implementación de este mercado que se inicia con acuerdos bilaterales de venta de gas natural y capacidad de transporte entre los agentes participantes, para posteriormente dar paso a las subastas electrónicas del día a día. Asimismo, se conocerá las principales disposiciones contractuales que suelen incorporarse en los acuerdos bilaterales de transferencia de capacidad de transporte. Finalmente, se analizarán dos deficiencias importantes ocurridas en estos años de funcionamiento, como son la restricción para la transferencia de volúmenes de gas natural y la no inclusión en este mercado de excedentes de capacidad del servicio de distribución por redes de ductos contratado por los consumidores.

In this thesis, we address several generic problems concerned with procurement of tasks from a crowd that consists of strategic workers with uncertainty in their qualities. These problems assume importance as the quality of services in a service marketplace is known to degrade when there is (unchecked) information asymmetry pertaining to quality. Moreover, crowdsourcing is increasingly being used for a wide variety of tasks these days since it offers high levels of flexibility to workers as well as employers. We seek to address the issue of quality uncertainty in crowdsourcing through mechanism design and machine learning. As the interactions in web-based crowdsourcing platform are logged, the data captured could be used to learn unknown parameters such as qualities of individual crowd workers. Further, many of these platforms invite bids by crowd workers for available tasks but the strategic workers may not bid truthfully. This warrants the use of mechanism design to induce truthful bidding. There ensues a complex interplay between machine learning and mechanism design, leading to interesting technical challenges. We resolve some generic challenges in the context of the following problems. Design of a quality eliciting mechanism with interdependent values We consider an expert sourcing problem, where a planner seeks opinions from a pool of experts. Execution of the task at an assured quality level in a cost effective manner turns out to be a mechanism design problem when the individual qualities are private information of the experts. Also, the task execution problem involves interdependent values, where truthfulness and efficiency cannot be achieved in an unrestricted setting due to an impossibility result. We propose a novel mechanism that exploits the special structure of the problem and guarantees allocative efficiency, ex-post incentive compatibility and strict budget balance for the mechanism, and ex-post individual rationality for the experts. Design of an optimal dimensional crowdsourcing auction We study the problem faced by an auctioneer who gains stochastic rewards by procuring multiple units of a service from a pool of heterogeneous strategic workers. The reward obtained depends on the inherent quality of the worker; the worker’s quality is fixed but unknown. The costs and capacities are private information of the workers. The auctioneer is required to elicit costs and capacities (making the mechanism design dimensional) and further, has to learn the qualities of the workers as well, to enable utility maximization. To solve this problem, we design a dimensional multi-armed bandit auction that maximizes the expected utility of the auctioneer subject to incentive compatibility and individual rationality while simultaneously learning the unknown qualities of the agents. Design of a multi-parameter learning mechanism for crowdsourcing We investigate the problem of allocating divisible jobs, arriving online, to workers in a crowd-sourcing platform. Each job is split into a certain number of tasks that are then allocated to workers. These tasks have to meet several constraints that depend on the worker performance. The performance of each worker in turn is characterized by several intrinsic stochastic parameters. In particular, we study a problem where each arriving job has to be completed within a deadline and each task has to be completed, honouring a lower bound on quality. The job completion time and quality of each worker are stochastic with fixed but unknown means. We propose a learning mechanism to elicit the costs truthfully while simultaneously learning the stochastic parameters. Our proposed mechanism is dominant strategy incentive compatible and ex-post individually rational with asymptotically optimal regret performance.

Este trabalho adota a técnica de simulação baseada em agentes para analisar o processo de precificação de energia comercializada no ambiente de contratação regulada (leilões) do mercado elétrico do Brasil. Nesse contexto, são simulados leilões de energia nova - produto fonte eólica. O simulador dos leilões de energia do Brasil foi construído através de programação realizada em matlab. Nesse programa, é possível comparar a escolha de lances de vendedores participantes nos pleitos. Os agentes (vendedores) participantes dos leilões aprendem com o decorrer dos leilões simulados. A aprendizagem é determinada através da utilização de variação do algoritmo Q-learning. Os resultados claramente demonstram que as técnicas de aprendizagem consideradas têm resultados mais favoráveis do que escolhas aleatórias (sem aprendizagem). Considerando outro ponto de vista, é possível verificar diferença de média de preços nos leilões entre os perfis de geradores públicos e privados. Além disso, é possível afirmar que o preço da energia se altera dada alteração na participação relativa de vendedores públicos ou privados nos pleitos. / This thesis adopts an agent based simulation in order to analyses the pricing process of energy that is negotiate by auctions in Brazil. In this work, wind energy power auctions are simulate. The model was developed in Matlab platform, and so, it was possible to compare the bidding process of the players in those auctions. The players learn during the auctions, and the process of learning is defined by a variation of the Q-learning algorithm. The results of the research show that when Q-learning is considered by generators there are more benefits than it is not. From another point of view, it is possible to say that there is difference between the prices of public and private players (enterprises that sell Wind energy). Besides it is possible to say that when the number of public and private players in an auction change the energy price.

nÃo hà / O objetivo da presente dissertaÃÃo à medir os impactos da introduÃÃo da modalidade do PregÃo EletrÃnico na PolÃtica de Compras Governamentais do Estado do CearÃ, buscando verificar se o fato resultou em economia para os cofres pÃblicos, como tambÃm estimar a agilidade do tempo de conclusÃo dos processos licitatÃrios. Para tanto se buscou estabelecer uma comparaÃÃo entre a economia gerada pelas modalidades de Carta Convite e Tomada de PreÃo em perÃodo anterior ao PregÃo (1994/1999) e apÃs este (2007/2010). Para estimar a eficÃcia do pregÃo eletrÃnico com as supracitadas modalidades de licitaÃÃo foram utilizados dados obtidos com a aquisiÃÃo de bens da mesma natureza nos ÃrgÃos pÃblicos estaduais, e tambÃm pesquisa nos sites do MinistÃrio do Planejamento, OrÃamento e GestÃo, e do Sistema do Banco do Brasil. Utilizou-se para anÃlise, estatÃstica de regressÃo simples linear. O modelo proposto utilizou trÃs variÃveis: preÃo de aquisiÃÃo, tempo de permanÃncia do processo e nÃmero de participantes, e uma dummy de qualidade. Analisando estas variÃveis, verifica-se que o tempo de permanÃncia e que o nÃmero de participantes nÃo sÃo estatisticamente relevantes para o preÃo de aquisiÃÃo, demonstrando que a modalidade da licitaÃÃo nÃo aparece como fator determinante da eficiÃncia. Jà a dummy de qualidade mostrou efeito positivo sobre a aquisiÃÃo de bens de tecnologia. / The purpose of this paper is to measure the impact of the introduction of Electronic Auction mode in Government Procurement Policy of the State of CearÃ, seeking to verify the fact resulted in savings for the public coffers, but also estimate the speed of the completion time of processes bidding. For that we sought to establish a comparison between the savings generated by the modalities of Invitation Letter and Decision-Price in the period prior to Auction (1994/1999) and after that (2007/2010). To estimate the efficiency of electronic trading with the above methods of procurement used data obtained with the purchase of the same nature in the public state, and also research in sites, the Ministry of Planning, Budget and management and System of the Bank of Brazil. Was used for analysis, simple linear regression statistics. The proposed model used three variables: purchase price, length of stay and number of process participants, and a dummy of quality. Analyzing these variables, it appears that the length of stay and the number of participants are not statistically significant for the purchase price, showing that the mode of bidding does not appear as determinant of efficiency. Since the dummy showed positive effect of quality on the acquisition of property.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-03-16T16:28:54Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 1_TESE_Fernando Rolim_UFPE_CTG_FINAL ✓.pdf: 11444878 bytes, checksum: 49ba52a66dd0e0151594254313b84808 (MD5) / Made available in DSpace on 2017-03-16T16:28:54Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 1_TESE_Fernando Rolim_UFPE_CTG_FINAL ✓.pdf: 11444878 bytes, checksum: 49ba52a66dd0e0151594254313b84808 (MD5) Previous issue date: 2015-10-29 / Esta Tese analisa a competitividade de procedimentos licitatórios para a delegação dos serviços de Transporte Público Urbano por Ônibus (TPUO) através do desenvolvimento e aplicação de um original e inédito método de análise baseado na adjunção da Teoria da Regulação Econômica (aqui vista como fenômeno que trata dos mercados nos momentos ex ante e ex post licitações) com a Teoria dos Leilões (aqui vista como processo que trata dos fenômenos que ocorrem durante os próprios procedimentos licitatórios). O método foca na análise tanto das estruturas de mercado ex ante licitações, como nos termos dos editais das licitações, para especular se as licitações tendem a ser competitivas, no sentido de atrair o maior número de empresas entrantes e incumbentes possível às disputas, de estabelecer um ambiente contestável, e de obter contratações mais econômicas. No método desenvolvido é priorizada a adoção de pressupostos baseados em elementos técnicos e econômicos, pois se entende que esses elementos devem limitar a discricionariedade do gestor público, ainda que a legislação eventualmente lhe faculte várias possibilidades para a tomada de decisão. A hipótese da pesquisa, de que em geral as licitações brasileiras para a delegação de serviços de TPUO não têm privilegiado a competitividade, é confirmada pelo teste de hipótese feito, qual seja, a aplicação do método de análise nos editais das Concorrências 02/2013 e 03/2013 do Grande Recife Consórcio de Transportes (CTM) para a delegação de serviços de TPUO na Região Metropolitana do Recife (RMR). Diante dos achados da pesquisa, resta especular que a explicação para a realidade constatada não está na análise econômica. Nesse sentido, a Tese pode fechar um ciclo de pesquisas conduzidas pela academia nacional nas últimas duas décadas, que tem tentado buscar respostas para explicar o porque de não haver competitividade em licitações para delegação de serviços de TPUO no Brasil. As respostas provavelmente não se encontram no campo da Economia, a despeito de a Tese mostrar que a competitividade, segundo a Teoria da Regulação Econômica e a Teoria dos Leilões, não vir sendo atingida nas licitações brasileiras. Resta agora explorar outros caminhos e searas, que enfoquem e estudem as relações sociais e outras disciplinas que eventualmente possam desvendar o que efetivamente está subjacente à falta de competitividade, para entender e diagnosticar, na prática, as forças que impedem a inserção de adequados níveis de competitividade nos mercados de TPUO brasileiros. / This thesis analyzes the competitiveness of competitive tendering (CT) procedures aimed at the delegation of the Urban Bus Public Transport (TPUO) services through the development and application of a method of analysis based on the addition of the Theory of Economic Regulation (seen here as a phenomenon that deals with the markets ex ante and ex post competitive tendering processes) with the Auction Theory (seen here as a process that deals with the phenomena that occur during the competitive tendering procedures). The method focuses on the analysis of both the ex ante CT market structures and the terms of the notices to tender, in order to speculate whether the bids tend to be competitive from the perspective of attracting as many entrant and incumbent firms as possible, of establishing a contestable environment, and of fostering more economic contracts. In the method developed it is prioritized the adoption of assumptions based on technical and economic aspects, since it is considered that these aspects should limit the discretion of the public authority, even when the legislation allows different choices for the decision maker. The hypothesis of the research, that in general the Brazilian CT procedures for the delegation of the TPUO services have not privileged competitiveness, is confirmed by the test of hypothesis done, that means, the application of the method upon the notices to tender 02/2013 03/2013 of the Greater Recife Transport Consortium (CTM) for the delegation of TPUO services in the Metropolitan Region of Recife (RMR). Before the research findings, it may be speculated that the explanation for the reality observed can not be found in the economic analysis. In this sense, the Thesis may close a research effort conducted by Brazilian scholars throughout the last two decades, who have been trying to find answers to explain the reason for the lack of competitiveness in the CT procedures for de delegation of the TPUO services in Brazil. Probably answers may not be found in the Economy field, even though the Thesis has shown that competitiveness, according to the Theory of Economic Regulation and the Auction Theory, has not been achieved in the Brazilian case. Thus, it would be appropriate to explore other fields that focus and study social relations and other disciplines which might uncover what is actually behind the lack of competitiveness, to understand and diagnose, in practice, the forces that prevent the insertion of appropriate levels of competitiveness in the Brazilian TPUO markets.

nÃo hà / O propÃsito deste trabalho visa a examinar um comparativo na PolÃtica de Compras Governamentais do Estado do Cearà em perÃodo anterior ao pregÃo e durante este (1999 e 2009, respectivamente). Para comparar a eficÃcia do pregÃo com outras modalidades de licitaÃÃo, mais precisamente carta-convite e tomada de preÃos, foram utilizados dados obtidos com bens adquiridos da mesma natureza nos ÃrgÃos pÃblicos estaduais. Utilizou-se para anÃlise, estatÃstica de regressÃo simples linear. O modelo proposto utilizou trÃs variÃveis: preÃo de aquisiÃÃo, tempo de permanÃncia do processo e nÃmero de participantes. Analisando estas variÃveis, verifica-se que os preÃos e o tempo de permanÃncia nÃo sÃo estatisticamente relevantes e que o nÃmero de participantes tem relaÃÃo significativa com o preÃo de aquisiÃÃo, demonstrando que a modalidade da licitaÃÃo nÃo aparece como fator determinante da eficiÃncia. / The purpose of this study is to analyze a comparison in Cearà State Government Purchase Politics in a period before trading and during it (in the years of 1999 and 2009, respectively). To compare trading efficiency and others licitation modalities it was used data of acquired properties of the same nature. Regression statistical analysis was used. The proposed model analyzed three variables: acquisition price, time of process permanency and number of participants. It was verified that acquisition price and time of process permanency are not statically relevant, and that the number of participants has a significant relation to acquisition price, indicating that the licitation modality does not represent a determinant factor of efficiency.

The main aim of the thesis is the comparison of the e-auction and the direct sale of apartments and to find answers to the research questions: Does the way of sale affect the price of the apartment? Are the prices higher in e-auction than in direct sales? In the theoretical part, the issue of auctions and direct sales is described and the development on the Czech real estate market is outlined. Analytical part analyzes data from e-auction and direct sale of apartements, and research questions are answered.

The increasing volume of greenhouse gases in the atmosphere has led to the creation of European Emissions Trading System (EU ETS). This system should also fulfil an incentive function to reduce emissions. The EU ETS also participates in revenues of the state budgets. This master thesis deals with impacts of EU ETS on revenues of state budgets for each member states of this system. The thesis is compiled with calculations of revenues of state budgets. This methodology is then applied to the assessment of the impact of auctioning of emission allowances on the Czech state budget and is demonstrated on three possible scenarios.