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)

Denna studies syfte är att undersöka tilliten på nätauktionshemsidorna. Tillit i denna studie ärrelaterat till informationen som finns tillgänglig om användarna. Detta innebär att ominformationen om användarna är få eller inte tillgänglig är minskas tilliten och saknad av tillitskapas. Denna studie är baserad på ett dataunderlag bestående av 100 användare, 50användare från den internationella auktionshemsidan eBay och 50 användare från denskandinaviska auktionshemsidan Tradera.Den teoretiska referensramen i denna studie baseras på Akerlofs teori ”Market for Lemons”,som beskriver hur avsaknad av information används för att skapa en marknad för ”lemons”,detta innebär att säljare med dåliga produkter slår ut säljare med bra produkter från enmarknad och en marknad med dåliga produkter skapas för att informationen inte är tillgängligför köparna.Undersökningen visar att det finns gott om information om varje användare. Informationen ärdetaljerat och sträcker sig till när användaren skapade sitt konto. Köpare och säljare har enmöjlighet att lämna ett omdöme vid avslutat transaktion i enlighet hur de upplevde auktionen.Detta omdöme kan varken ändras eller raderas. Omdömen skapar tillit; om en säljare har ettlågt omdöme kan man inte lita på att de fullföljer sina auktioner. Tilliten i undersökningen varexceptionellt högt. Ingen av användarna i dataunderlaget hade en feedback som understeg90%; detta innebär att åtminstone 90% av alla auktioner var av positiv karaktär och att bådesäljaren och köparen var nöjda med sina transaktioner. Undersökningen visar också att mångaanvändare på eBay bedriver någon form av verksamhet. Mer än hälften av användarna idataunderlaget hade en butik på eBay och sålde både nya och begagnade föremål.Slutsatsen från denna undersökning är att informationen om varje användare är tillräckligt föratt föra bort dåliga säljare från auktionsmarknaden och behålla de bra säljarna. Detta leder tillen hög tillitsnivå hos användarna på både eBay och Tradera. / The aim of this study is to investigate trust in auction sites. Trust in this study is related to theinformation available about the users, this means if the information about the users is scarcethe trust is lowered and mistrust is created. The study is based on dataset collected from 100users, 50 users from the international auction site eBay and 50 from the Scandinavian auctionsite Tradera.The theoretical framework of the study is based on Akerlof’s theory “Market for Lemons”,which describes how the lack of information is used to create a market for lemons, that is,sellers with bad products pushing out sellers with good products from the market and a marketfor bad products are created because the information is hidden from the buyers.The investigation shows that there is a lot of information about each user. The information isdetailed and can be traced back to when the user first created the account. Buyers and sellershave the opportunity to leave feedback of the transaction according to their own experience;this feedback can’t in turn be erased or changed. The feedback creates the base of trust; if aseller has low feedback they can’t be trusted to fulfill their transactions. Trust in theinvestigated users was exceptionally high. None of the users in the dataset had a feedbackbelow 90%; this means at least 90% of all the transactions were positive and the seller andbuyer were satisfied with the transaction; that is the information provided by the seller wastruthfully. The investigation also shows that many users on eBay are conducting a form ofbusiness enterprise. More than half of the users in the dataset have a “store” on eBay and usethe store to sell both new and used products.The conclusion from the investigation is that the information about each user is sufficient toscreen out bad sellers, or the lemons, from the auction market and only keep the good sellers.This in turn leads to a high trust level among the users at both eBay and Tradera.

The first chapter of this thesis gives a detailed picture of commonly used structural estimation techniques for several types of auction models. Next chapters consist of essays in which these techniques are utilized for empirical analysis of auction environments. In the second chapter we discuss the identification and estimation of the distribution of private signals in a common value auction model with an asymmetric information environment. We argue that the private information of the informed bidders are identifiable due to the asymmetric information structure. Then, we propose a two stage estimation method, which follows the identification strategy. We show, with Monte-Carlo experiments, that the estimator performs well. Third chapter studies Outer Continental Shelf drainage auctions, where oil and gas extraction leases are sold. Informational asymmetry across bidders and collusive behavior of informed firms make this environment very unique. We apply the technique proposed in the second chapter to data from the OCS drainage auctions. We estimate the parameters of a structural model and then run counterfactual simulations to see the effects of the informational asymmetry on the government's auction revenue. We find that the probability that information symmetry brings higher revenue to the government increases with the value of the auctioned tract. In the fourth chapter, we make use of the results in the multi-unit auction literature to study the Balancing Energy Services auctions (electricity spot market auctions) in Texas. We estimate the marginal costs of bidders implied by the Bayesian-Nash equilibrium of the multi-unit auction model of the market. We then compare the estimates to the actual marginal cost data. We find that, for the BES auction we study, the three largest bidders, Luminant, NRG and Calpine, have marked-down their bids more than the optimal amount implied by the model for the quantities where they were short of their contractual obligations, while they have put a mark-up larger than the optimal level implied by the model for quantities in excess of their contract obligations. Among the three bidders we studied, Calpine has come closest to bidding its optimal implied by the Bayesian-Nash equilibrium of the multi-unit auction model of the BES market.

This thesis studies the impact of sequential auction design on participant behavior from both a theoretical and an empirical viewpoint. In the first of the two analyses, three sequential auction designs are characterized and compared based on expected profitability to the participants. The optimal bid strategy is derived as well. One of the designs, the alternating design, is a new auction design and is a blend of the other two. It assumes that the ability to bid in or initiate an auction is given to each side of the market in an alternating fashion to simulate seasonal markets. The conditions for an equilibrium auction design are derived and characteristics of the equilibrium are outlined. The primary result is that the alternating auction is a viable compromise auction design when buyers and suppliers disagree on whether to hold a sequence of forward or reverse auctions. We also found the value of information on future private value for a strategic supplier in a two-period case of the alternating and reverse auction designs. The empirical work studies the cause of low aggregation of timber supply in reverse auctions of an online timber exchange. Unlike previous research results regarding timber auctions, which focus on offline public auctions held by the U.S. Forest Service, we study online private auctions between logging companies and mills. A limited survey of the online auction data revealed that the auctions were successful less than 50% of the time. Regression analysis is used to determine which internal and external factors to the auction affect the aggregation of timber in an effort to determine the reason that so few auctions succeeded. The analysis revealed that the number of bidders, the description of the good and the volume demanded had a significant influence on the amount of timber supplied through the online auction exchange. A plausible explanation for the low aggregation is that the exchange was better suited to check the availability for custom cuts of timber and to transact standard timber.

Internet technology (IT) has changed the way information is disseminated, which has led to changes in transaction-making and the creation of new electronic markets. This has also led to the emer-gence of new types of online intermediaries, and new selling mechanisms. Since most online selling involves commodity goods and the discovery of low prices, the design of selling mechanism primarily focuses on the disclosure of price information. Low-price discovery selling mechanisms, however, have caused buyers to shift from one mechanism to another to get the best deals. Online sellers are facing profit pressures as a result. Price information only addresses a portion of consumer needs though. They need information to identify uncertainties that may harm them during transactions. Consumers also search for products and services that fit their individual preferences and are willing to pay a price premium for such offerings. Sellers have to offer additional information and to do decommoditization, or consumers will abandon selling mechanisms that do not match their needs. This dissertation examines these issues in three essays. It explores two online selling mechanisms: online group-buying auctions and a la carte pricing schemes in airline industry. The a la carte pricing is to offer flexible pricing to consumers. The research employs an Internet-based experimental test bed, a single-firm empirical case study, and an econometric model to test the relevant theories. I evaluate the design of online group-buying auctions, where consumers are more uncertain about group-buying as a mechanism for organizing economic exchange. I also evaluate the design of online selling mechanisms in the air travel services industry, where digitally-intermediation has created problems with suppliers¡¦ ownership of their customers and increasing channel conflicts. The results indicate that the dominance of price in consumer purchase decisions can be mitigated by complementary information, as well as value-added product and service information that an online selling mechanism provides. Consumer information requirements are dynamic and inconsistent though. So an effective selling mechanism must identify how to disclose an adequate amount of information to consumer. Some of the new mechanism designs that have emerged have produced a means for sellers to be more effective. My findings suggest that, in addition to price transparency, online selling mechanisms also affect transaction completion uncertainty, and support the expression of personal preferences.

This dissertation, which consists of three essays, studies online auctions both theoretically and empirically. The first essay studies a special online auction format used by eBay, “Buy-It- Now” (BIN) auctions, in which bidders are allowed to buy the item at a fixed BIN price set by the seller and end the auction immediately. I construct a two-stage model in which the BIN price is only available to one group of bidders. I find that bidders cutoff is lower in this model, which means, bidders are more likely to accept the BIN option, compared with the models assuming all bidders are offered the BIN. The results explain the high frequency of bidders accepting BIN price, and may also help explain the popularity of temporary BIN auctions in online auction sites, such as eBay, where BIN option is only offered to early bidders. In the second essay, I study how bidders’ risk attitude and time preference affect their behavior in Buy-It-Now auctions. I consider two cases, when both bidders enter the auction at the same time (homogenous bidders) thus BIN option is offered to both of them, and when two bidders enter the auction at two different stages (heterogenous bidders) thus the BIN option is only offered to the early bidder. Bidders’ optimal strategies are derived explicitly in both cases. In particular, given bidders’ risk attitude and time preference, the cutoff valuation, such that a bidder will accept BIN if his valuation is higher than the cutoff valuation and reject it otherwise, is calculated. I find that the cutoff valuation in the case of heterogenous bidders is lower than that in the case of homogenous bidders. The third essay focuses on the empirical modeling of the price processes of online auctions. I generalize the monotone series estimator to model the pooled price processes. Then I apply the model and the estimator to eBay auction data of a palm PDA. The results are shown to capture closely the overall pattern of observed price dynamics. In particular, early bidding, mid-auction draught, and sniping are well approximated by the estimated price curve.

Title from PDF of title page. / Document formatted into pages; contains 117 pages. / Thesis (M.S.C.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The modern economy includes a variety of markets, and the Internet has opened opportunities for efficient on-line trading. Researchers have developed algorithms for various auctions, which have become a popular means for on-line sales. They have also designed algorithms for exchange-based markets, similar to the traditional stock exchange, which support fast-paced trading of rigidly standardized securities. In contrast, there has been little work on exchanges for complex nonstandard commodities, such as used cars or collectible stamps. We propose a formal model for trading of complex goods, and present an automated exchange for a limited version of this model. The exchange allows the traders to describe commodities by multiple attributes; for example, a car buyer may specify a model, options, color, and other desirable properties. / ABSTRACT: Furthermore, a trader may enter constraints on the acceptable items rather than a specific item; for example, a buyer may look for any car that satisfies certain constraints, rather than for one particular vehicle. We present an extensive empirical evaluation of the implemented exchange, using artificial data, and then give results for two real-world markets, used cars and commercial paper. The experiments show that the system supports markets with up to 260,000 orders, and generates one hundred to one thousand trades per second. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 173-180).

Darbo tikslas : Išanalizuoti AB „Vilkijos ūkis“ naudojamas žvėrelių auginimo technologijas, ekonominius veiklos rezultatus ir įvertinti ūkio plėtros galimybes bei rizikos veiksnius. Darbo uždaviniai: 1. išanalizuoti brangiakailės žvėrininkystės būklę Lietuvoje ir pasaulyje; 2. apžvelgti pagrindinius veiksnius, darančius įtaką brangiakailius žvėrelius auginančių ūkių produkcijai (auginimo technologijos, ligos, bandos formavimas); 3. išanalizuoti ir įvertinti žvėrininkystės ūkio ekonominę padėtį ir galimybes kailių rinkoje. Tyrimo metodai ir sąlygos. Lapių ir audinių auginimo technologijų ir kailių rinką įtakojančių veiksnių teoriniams tyrimams buvo analizuota, apibendrinta, sisteminta ir lyginta mokslinė literatūra. Tyrimams buvo naudojami AB „Vilkijos ūkis“ 2004 – 2007 m. ūkinės veiklos duomenys. Praktinė tyrimo dalis yra paruošta naudojant pirminės ir antrinės informacijos sisteminimo, apibendrinimo bei matematinius statistinius duomenų apdorojimo metodus. Duomenų analizei naudoti duomenų grupavimo, apibendrinančių rodiklių sudarymo metodai. Buvo skaičiuojama dinamikos eilutės vidutiniai rodikliai, vidurkiniai lygiai, absoliutiniai dinamikos eilutės pokyčiai, pokyčio tempai. Taip pat taikėme grafinės analizės metodą. Statistiniai rodikliai apskaičiuoti naudojant skaičiuoklę Excel. Tyrimo rezultatai : 1. Visi Lietuvoje brangiakaile žvėrininkyste užsiimantys ūkiai produkciją realizuoja vienodomis sąlygomis – užsienio aukcionuose. Skirtingų rūšių kailių paklausa ir kaina... [toliau žr. visą tekstą] / Objectives: Analyze fur bearing animals breeding technologies, results of economic activity in „Vilkijos ūkis“, assess the posibilities of farm development and risk factors. Tasks: 1. Analyze the condition of fur animal husbandry all over the world and in Lithuania; 2. Overlook main factors influencing the production of fur breeding farms (breeding technologies, diseases, herd formation); 3. Analyze and assess the economic situation of fur breeding farms and opportunities in fur market. Material and methods. Scientific literature was analyzed, structured and compared for theoretical research of factors influencing breeding technologies and fur market of foxes and minks. Economical activity data of „Vilkijos ūkis“ (2004 - 2007) was used in this research. Practical part of the research is prepared using mathematical statistical data processing methods of primary and secondary information systematization and generalization. Data batching, resumptive rates formation methods were used for data analysis. There was used calculation of dynamics line average indexes, average levels, absolute alterations of dinamics lines, alteration rates. Results of the work: 1. All fur breeding animal farms in Lithuania sell their production in equal conditions – foreign auctions. Demand and price of different fur kinds is very hesitative, because fur market is dictated by heavily forecasted factor – fashion trends; 2. Amounts of farm production are stable – though general number of fur... [to full text]

Šiame magistriniame darbe autorius gvildena iki šiol teisinėje literatūroje mažai nagrinėtą elektroninių aukcionų temą. Ši tema nagrinėjama trimis aspektais. Pirmiausia, išnagrinėjami tradiciniai aukcionai, kaip e. aukciono pagrindas. Ištiriama aukcionų teorija, aukcionų rūšys, atsižvelgiama į tai kaip jie reglamentuojami Lietuvoje, išskiriami esminiai požymiai ir pagal juos atskleidžiama aukciono sąvoka. Sekančiame etape išnagrinėjamas e. aukciono, tradicinio aukciono ir e. komercijos santykis. Ištiriama, kuo pasižymi ir kokių ypatumu turi e. aukcionai, kokią įtaką jie daro teisiniams santykiams ir kaip juos keičia. Daug dėmesio skiriama ne tik teisės aktų analizei, bet ir teismų praktikai. Atsižvelgiama kokios bylos buvo nagrinėjamos pasaulyje, kokie sprendimai buvo priimti ir kas išdėstyta bylos argumentuojamoje dalyje. Pagal tai pateikiamos autoriaus rekomendacijos, kaip galėtų būti reguliuojama aukcionų veikla Lietuvoje. Galiausiai, nagrinėjamos teisės pažeidimų e. aukcionuose problemos. Darbe pateikiama teisės pažeidimų teorinė medžiaga, problemos aktualumas, bei pasaulyje vyraujantys įvairių įstaigų, įmonių ir organizacijų sprendimai šiai problemai spręsti. Atsižvelgiama į tai ar šie sprendimai galėtų būti pritaikyti Lietuvoje, kokios kliūtys iškyla jų įgyvendinimui ir kaip jas reikėtų panaikinti, koks turėtų būti valstybinis reguliavimas neteisėtoms veikoms užkirsti. Taigi, šis darbas yra vienas pirmųjų žingsnių į Lietuvoje dar naują ekonominio gyvenimo sritį... [toliau žr. visą tekstą] / This Master’s thesis is a research on the online auctions law. The paper consists of three parts. In the first part the author introduces traditional auctions as the basis of online auctions. There is the analysis of the auctions theory, regulation, essential features and clear definitions. In the second part comparative analysis is made on the traditional auctions and online auctions. A closer look reveals that there exist considerable differences that may cause legal controversy. Much of attention is paid to the court ruling in different law systems and countries such as Australia, Germany, UK, USA and etc. The last chapter of the work is designed for fraudulent activities in online auctions, and research of legal regulation solutions to dissolve it.