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Online auctions are arguably one of the most important and distinctly new applications of the internet. The predominant player in online auctions, eBay, has over 18.9 milllion users, and it was the host of over $5 billion worth of goods sold in the year 2000. Using methods from approximate dynamic programming and integer programming, we design algorithms for optimally bidding for a single item online auction, and simultaneous or overlapping multiple online auctions. We report computational evidence using data from eBay's web site from 1772 completed auctions for personal digital assistants and from 4208 completed auctions for stamp collections that show that (a) the optimal dynamic strategy outperforms simple but widely used static heuristic rules for a single auction, and (b) a new approach combining the value functions of single auctions found by dynamic programming using an integer programming framework produces high quality solutions fast and reliably. / Singapore-MIT Alliance (SMA)

There is a growing interest in electronic auctions in the literature. Many researchers work on the single attribute version of the problem. Multi-attribute version of the problem is more realistic. However, this brings a substantial difficulty in solving the problem. In order to overcome the computational difficulties, we develop an Evolutionary Algorithm (EA) for the case of multi-attribute multi-item reverse auctions. We generate the whole Pareto front using the EA. We also develop heuristic procedures to find several good initial solutions and insert those in the initial population of the EA. We test the EA on a number of randomly generated problems and compare the results with the true Pareto optimal front obtained by solving a series of integer programs. We also develop an exact interactive approach that provides aid both to the buyer and the sellers for a multi-attribute single item multi round reverse auction. The buyer decides on the provisional winner at each round. Then the approach provides support in terms of all attributes to each seller to be competitive in the next round of the auction.

The purpose of this multiple case study was to explore strategies managers in the online auction industry used to manage customer complaints to improve customer satisfaction. The targeted population consisted of 4 managers of online auction companies in the southwestern region of the United States. The conceptual framework for the study was Argyris and Sch�n's double-loop learning theory. Data were collected via semistructured interviews with business managers, observation of company operations and behaviors, review of documentation, and member-checking activities. Data analysis consisted of text interpretation of data and notes using coding techniques. Data analysis resulted in 5 themes: business orientation, customer purview, complaints handling, coping strategies, and learning abilities. The implications of this study for positive social change include facilitating the growth of online markets and increasing lower-cost purchasing opportunities for consumers with limited access to conventional marketplaces.

Um processo para o desenvolvimento de frameworks para sistemas de informação baseados na Web é proposto. Esse processo é composto pelos subprocessos de engenharia reversa de sistemas baseados na Web, de criação de uma linguagem de padrões e de construção e instanciação do framework. O subprocesso de engenharia reversa utiliza sistemas presentes na Web para derivar um modelo do domínio de aplicação. O desenvolvimento da linguagem de padrões é baseado no modelo do domínio e a construção do framework utiliza essa linguagem de padrões como base de todo o processo. Os produtos resultantes do uso desse processo para o domínio dos leilões virtuais, a Linguagem de Padrões LV e o Framework Qd+, também são apresentados. / A process for the development of web-based information systems frameworks is proposed. This process comprises a reverse engineering - for web-based information systems -, a pattern language creation, and a framework instantiation subprocesses. The reverse engineering subprocess uses existing WISs to derive an application domain model. The pattern language is created from the application domain model and the framework is developed from this pattern language. The deliverables of the application of this process to the online auctions domain, the Pattern Language for Online Auctions and the Qd+ Framework, are also presented.

Um processo para o desenvolvimento de frameworks para sistemas de informação baseados na Web é proposto. Esse processo é composto pelos subprocessos de engenharia reversa de sistemas baseados na Web, de criação de uma linguagem de padrões e de construção e instanciação do framework. O subprocesso de engenharia reversa utiliza sistemas presentes na Web para derivar um modelo do domínio de aplicação. O desenvolvimento da linguagem de padrões é baseado no modelo do domínio e a construção do framework utiliza essa linguagem de padrões como base de todo o processo. Os produtos resultantes do uso desse processo para o domínio dos leilões virtuais, a Linguagem de Padrões LV e o Framework Qd+, também são apresentados. / A process for the development of web-based information systems frameworks is proposed. This process comprises a reverse engineering - for web-based information systems -, a pattern language creation, and a framework instantiation subprocesses. The reverse engineering subprocess uses existing WISs to derive an application domain model. The pattern language is created from the application domain model and the framework is developed from this pattern language. The deliverables of the application of this process to the online auctions domain, the Pattern Language for Online Auctions and the Qd+ Framework, are also presented.

On the one hand, time-honored practices of open outcry, bazaar and other flea markets, as well as Sotheby's and Christie's, the traditional auction houses. On the other hand, the Internet technology quickly and cheaply connects people anywhere in the world at anytime. A true love story then began and gave rise to online auctions, which are undoubtedly one of the greatest successes of e-commerce. Thanks to the Internet, individual consumers, average people, generally used to posted prices, discover an efficient mechanism of price setting. The weak popularity of auctions until the dawn of the third millennium (auctions were intended to B2B transactions, or to B2C transactions but in specific markets, such as the art market) certainly justifies the lack of interest of researchers in marketing for this mechanism. On the other hand, economists made auctions one of their favorite topics, as this mechanism constitutes a wonderful application of game theory, which has been playing a preponderant role in economics for twenty-five years. Entitled “Essays on Online Auction Design and Bidding Behavior”, this doctoral dissertation helps enrich the traditional economic approach of auctions by a behavioral and dynamic approach. The original part of the research is structured in three main stages, which go deeper and deeper in the study of bidders' behavior and auction dynamics. The whole research is based on online auctions organized by the French airline company Air France and by the auction site eBay. In the first stage of the research, on the basis of hypotheses coming from the auction theory, the impact of auction rules on bidders’ participation and seller's revenue is econometrically studied, using simultaneous equations models and the 2SLS method. Does a high opening bid have a negative effect on the number of bidders and a positive one on the auction revenue, as predicted by the auction theory? Do sequential auctions of similar items lead to similar auction price? These are examples of questions that are investigated. While the auction theory literature typically takes the number of bidders as exogenously given, we chose to consider it as endogenous. Even though an increasing number of researchers acknowledge the endogenous feature of auction participation, no empirical study really takes this feature into account. Hypotheses from the auction theory turn out to be confirmed, as far as the minimum bid and the number of bidders are concerned. Interesting results are found regarding the performance of sequential auctions of similar items, since auctions in a sequence turn out to yield increasing revenues. Furthermore, the impact of the starting bid turns out to be moderated by the effect of these sequential auctions. In the second stage of this research, a disaggregated perspective (at the bidder’s level) is adopted, since a typology of bidding behaviors based on bidders' choices is built. This part is thus aimed at investigating whether heterogeneity exists in bidder’s behavior in online auctions, contrary to the longstanding assumption of homogenous, rational and strategic bidders made by the auction theory. A clustering analysis is conducted, based on decisions that bidders have to make during an auction, whose keywords are certainly: when? How? How much? For example: do bidders submit a small or a large number of bids? Do they react quickly when they lose auction leadership? When do they make their bids: at the beginning of the auction, at the end of it, or during the whole auction? What increment do they use? Results, based on two different samples related to Air France and eBay auctions provide a description of different bidding behaviors. The analysis focusing on Air France auctions highlights five types of bidding behavior: jump bidders, rational bidders, active bidders, bottom fishers and pioneers. Slightly different results are obtained for eBay auctions, since six types of bidding behavior are highlighted: snipers, evaluators, unmasking bidders, bottom fishers, pioneers and late pioneers. A closer look is given to the group of bidders who turned out to win an auction, in order to determine whether these bidders are characterized by specific bidding decisions, and thus, by specific bidding behaviors. The third stage focuses on the dynamic bidding process of an English auction, by specifically studying the impact of signals – namely, promotional messages – sent during an online auction on the final auction price. It proposes to test a model of the genesis and the impact of these messages aimed at informing current bidders and potential bidders about the item or urging them to submit a bid. This impact is modeled through a disaggregated and dynamic model. It exploits the recent behavioral view that each bid submitted by a bidder in an English auction is a particular decision that may be influenced by signals sent by the auctioneer during the auction, that is, between the decisions that the bidder makes. This model simultaneously takes into account the following three factors: (i) the direct impact of marketing messages on the auction price when messages affect bidders’ valuations, (ii) the indirect impact of messages on this price when messages attract a new bidder to the auction, and (iii) the possibility that the auctioneer’s strategy for sending messages depends on past events in the auction and on the timing of past messages. In this model, we thus propose that messages influence final auction prices through a dual-path system. The model also reflects an important feature of auction messages, which is the real time interactivity between the auctioneer and auction participants. The results, obtained through Bayesian inference, support the proposed model. This doctoral dissertation globally helps better understand bidders’ behavior in view of the rules set by the seller, and estimate how this seller can maximize his/her revenues. The main original aspects of this research consist in considering the English auction as a dynamic process and in focusing on bidders’ behavior, these two elements being ignored by economists. From a managerial point of view, this research can help online auction designers to better design their auctions in order to maximize their revenue.

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.

Baigiamajame magistro darbe nagrinėjamos internetinių aukcionų pritaikymo galimybės tarptautinei prekybai dailės kūriniais. Nagrinėjami pagrindiniai teoriniai principai, kuriais remiantis nustatomos internetinių aukcionų pritaikymo galimybės tarptautinei prekybai dailės kūriniais: dailės kūrinių specifika, teikiama nauda, rinkos dalyviai, internetinių aukcionų sistemos ypatumai, interneto tinklalapio elementų ir kultūrinių skirtumų įtaka tarptautinei prekybai. Pateiktas internetinių aukcionų efektyvumo ir pritaikymo tarptautinei rinkai vertinimo klausimynas, atlikta lyginamoji analizė Lietuvoje ir užsienyje plėtojamų internetinių aukcionų bei internetinių aukcionų pritaikymo tarptautinei prekybai dailės kūriniais perspektyvų analizė. Atsižvelgiant į literatūros šaltinių, statistikos analizę ir atliktus tyrimus, parengiami strateginiai sprendimai, skirti internetiniams aukcionams pritaikyti tarptautinei prekybai dailės kūriniais. Darbo pabaigoje pateikiamos apibendrinamos išvados ir pasiūlymai. / The final master thesis deals with online auction application possibilities of international trade in art works. To the main theoretical principles used to define online auctions range of possibilities of international trade in art works: the specificity of works of art, benefits, market participants, on-line auction system features, web site elements and cultural differences on international trade. There is submitted on-line auction efficiency and adaptation to international market assessment questionnaire, performed a comparative analysis of Lithuania and abroad evolving online auctions and a prospective analysis of online auctions for the international trade in art works. Then, using literary sources, statistical analysis and studies, strategic solutions is being presented, which would improve the online auctions possibilities and orientation of the international trade in art works. Finally the conclusions and suggestions are proposed.

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