Strategic Bidding for Multiple Units in Simultaneous and Sequential Auctions

A buyer in an electronic marketplace may be interested in buying a bundle of items, where any one item in the bundle may not be of particular interest. The emergence of online auctions allow such users to obtain bundles by bidding on different simultaneous or sequentially run auctions. Because the number of auctions and the number of combinations to form the bundles may be large, the bundle bidding problem becomes intractable and the user is likely to make sub-optimal decision given time constraints and information overload. We believe that an automated agent that takes user preferences and budgetary constraints and can strategically bid on behalf of a user can significantly enhance user profit and satisfaction. Our first step to developing such an agent is to consider bundles containing many units of a single item to be bought from auctions that sell only multiple units of one item type. We assume that users obtain goods over several days. Expectations of auctions and their outcome in the future allow the agent to bid strategically on currently open auctions. We present an expected utility based strategy to decide how many items to bid for in the current auctions, and the maximum price to bid for each item. We evaluate our proposed strategy in different configurations by varying the number of items sold per auction, number of concurrently running auctions, expected closing prices, etc. We simulate several multiple unit English auctions per day, over multiple days, where most of the bidders bid their true utilities drawn from a distribution. The strategic bidding agent has knowledge of this distribution and uses it to determine its bids. A strategic agent who looks farther ahead into the future produces larger returns when there are few strategic bidders. We also evaluate the effect of risk attitudes on the relative performance of the bidders.     

The effect of buyer feedback scores on internet auction prices

One of the major roles of Internet intermediaries is to help build trust between buyers and sellers for efficient and safe transactions. The buyer feedback system started in online auctions as one of the trust‐building mechanisms on the Internet. As the buyer feedback system is becoming a standard trust‐building mechanism in other e‐commerce sites as well as in online auction, there is an increasing interest about the impact of the buyer feedback system. On the top of recent studies investigating the effects of buyer feedback scores on auction prices, we provide empirical validations using more sophisticated methods. In this study, we tested the relationship between buyer feedback scores and bidding prices using an empirical data set from a leading consumer‐to‐consumer (C2C) Internet auction site. Data analysis results show a strong empirical validation of previous studies. Negative feedback is a significant price discount factor in the final auction price on the C2C Internet auction market. The results also show that potential buyers are more sensitive to negative feedback when they are considering buying inherently risky products such as used or refurbished products.     

When auction meets fixed price: a theoretical and empirical examination of buy-it-now auctions

Recently fixed pricing and auctions have been brought together in a new pricing format that offers bidders the option of prematurely ending an auction at a fixed price. The growing popularity of auctions presents an interesting pricing decision for managers: whether to sell at a fixed price, in a regular auction, or through a buy-it-now auction. This paper studies eBay’s buy-it-now auction and answers the following research questions: why is fixed price used at traditional auctions, will buy-it-now increase the seller’s profit, how is an optimal price determined, and how is the buy-it-now decision influenced by key factors such as the customer’s cost of participating in the auction, the seller’s reserve price, and the number of potential customers. Our results show that when customers make endogenous participation decisions according to their participation costs, buy-it-now auctions can increase both customers’ utility and sellers’ profit. Endogenous participation has important implications for seller’s pricing decisions such as price formats and levels. Depending on the level of the posted price, the resulting price format could be either fixed price, buy-it-now auction or pure auction. Therefore, the seller needs to be careful and take into account market conditions when posting a price at auctions. We empirically test the model assumptions and predictions using data collected from eBay.

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Reducing information asymmetry in the auctioning of non-perishable experience goods: The case of online wine auctions

We highlight the importance of reducing the perceived risk associated with information asymmetry for experience goods. We analyse a major online non-perishable experience good, wine, from the seller's perspective. The mechanism for lowering information asymmetry is the verification service offered by the auctioneer. By focusing on unsold items/lots, the wine and auction characteristics affecting the probability of a sale are identified. Results show that the verification of the wine's provenance increases the probability of sale by 5.7 percent and leads to an expected increase of 5.1 percent in the auction price. When both effects are combined, the increase in the expected revenue of the seller is 7.3 percent. We test and find no evidence of selection bias. Given the heterogeneity in wine prices, a quantile regression analysis shows how the results differ for high-priced wines compared to lower priced wines. Results highlight how the mechanisms to lower the degree of information asymmetry work both in attracting bidders to online auctions and encouraging bidders to submit higher bids.     

Efficiency Considerations in Online Auction Markets

The main contention of this article is that online auction markets are amenable to efficiency considerations akin to traditional financial markets. While the underlying assets traded are dissimilar between the financial and online auction markets, the fundamental principles that drive these markets are consanguineous in that similar efficiency notions are applicable. Based on the principles of arbitrage, we develop a set of efficiency criteria to evaluate the auction activity of new and identically described items. Two arbitrage principles, seller arbitrage and buyer arbitrage, are developed. These principles can be employed to evaluate the price behavior of temporally proximate auctions and to generate a useful benchmark to make efficiency evaluations. We find evidence of inefficiency for each of the items we empirically tested based on the data from eBay, currently the largest online auction house.     

Maximizing earnings and price fairness perceptions in online consumer-to-consumer auctions

We examine the effects of starting bids on seller earnings in online consumer-to-consumer auctions. As starting bids increase, and the number of bidders increase, seller earnings increase. Both the affiliated private value model and a reference price explanation explain seller earnings. Bidder price fairness perceptions are also evaluated and, higher starting bids positively impact price fairness perceptions for winning bidders but have an adverse effect on losing bidders. In total, these findings suggest that sellers receive greater earnings as well as no adverse price fairness perceptions from winning bidders by setting starting bids higher.     

The impact of jump bidding in online auctions

This paper reports findings of two field studies, conducted on a local online auction website, that compare bidding strategies in charity and non-charity auctions, focusing on the extent of jump bidding at different stages of auctions. Results indicate that jump bidding is negatively correlated with bidder entry and positively associated with ending prices. These correlations are greatest during the beginning stage of auctions and are substantially larger for charity auctions than for non-charity auctions. Additionally, early-stage jump bidding occurred more often in charity auctions (consistent with bidders trying to drive up prices in charity auctions), ending-stage jump bidding was more frequent in non-charity auctions (possibly used strategically to win the auction). Further, frivolous products tended to sell at a higher proportion of retail value in charity auctions, providing a replication of the results of previous researchers but in a field setting.     

Experts and Amateurs: The Role of Experience in Internet Auctions

The use of auctions as a pricing mechanism has grown dramatically over the last few years. The introduction of electronic auctions has significantly widened the pool of consumers who participate in auctions and increased the number of companies attempting to sell their products in an auction format. Previous empirical research on auctions has focused almost exclusively on the behavior of professional bidders in high stakes common value auctions or the behavior of students in laboratory experiments. We collect data on a large number of electronic auctions, across four product categories, to explore the behavior of consumers bidding in a real marketplace. In particular, we focus on the role experience plays in their bidding behavior to uncover whether consumer learning drives the bidding process towards outcomes described in the theoretical literature on auctions. We find that experience does indeed lead to behavior which is more consistent with theory although the proportion of experienced bidders who behave in a manner inconsistent with theory remains quite large.     

Consumer motivations and concerns in online auctions: an exploratory study

This investigates the reasons behind the dramatic growth of Internet auction companies such as eBay, exploring into why so many consumers have been motivated to turn to online auctions to purchase and sell goods. It is found that the ability to purchase items at lower prices than from retail stores is the primary motivation, along with having access to previously unobtainable items. Concerns mainly relate to potential fraudulent transactions, although the negative feedback system is found to be vital in the reduction of fears over fraud. Interaction with other auction users is found to be important for practical reasons such as information seeking, rather than for enjoyment. The main conclusion is that the benefits of using Internet auctions far outweigh the risks involved.     

Auction Fever! How Time Pressure and Social Competition Affect Bidders’ Arousal and Bids in Retail Auctions

Auction sites on the Internet frequently put bidders under time pressure or highlight the social competition that is inherent to auctions. Both aspects are believed to elicit an exciting shopping experience, which may culminate in auction fever. In two laboratory experiments, we investigate the process of auction fever in retail auctions and demonstrate when and how auction fever affects bidding behavior. In contrast to previous studies, we employ physiological measurements as an objective and continuous assessment of bidders’ arousal in addition to a subjective assessment of bidders’ emotions through psychometric scales. Moreover, we explicitly study the interaction of time pressure and social competition on arousal and bids. We find that bidders’ arousal is increased in high time pressure auctions and that this leads to higher bids in ascending auctions—but only when bidders compete with human opponents. Thus, social competition is the actual driver underlying the auction fever phenomenon. Furthermore, we show that the “joy of winning” is significantly stronger than the “frustration of losing” in ascending auctions. Finally, we discuss the implications of our findings for the design of retail auctions.     

A Network Bidder Behavior Model in Online Auctions: A Case of Fine Art Auctions

The marketing literature provides a solid understanding of auctions regarding final sales prices and many aspects of the processes that unfold to result in those outcomes. This research complements those perspectives by first presenting a new bidder behavior model that shows the role of emergent network ties among bidders on the auction outcome. Dyadic ties are identified as the bid and counter-bid patterns of interactions between bidders that unfold throughout the duration of an auction. These structures are modeled using network analyses, which enables: (1) a richer understanding of detailed auction processes, both within auctions and across auctions of multiple lots, (2) a mapping of the processes to the forecast of prices and the trajectory toward final sales prices, (3) the clear and early identification of key bidders who are influential to the bidding action and who impact final auction sales prices, and (4) the results clearly show that the network exchange patterns are significant and contribute to an understanding of auction processes and outcomes above and beyond simple economic predictors such as the number of bids or bidders or the bidders’ economic status. We conclude by providing some managerial implications for online auction houses and bidders.     

Impact of Reputation and Promotion on Internet Auction Outcomes: Finnish Evidence

The purpose of this article is to explore the impact of seller’s reputation and promotional methods on auction outcomes in the Finnish online auction website, Huuto.net. Multiple linear and logistic regression analyses are used to test a set of hypotheses. The dataset consists of 227 auctions of iPhone 4S 16 GB mobile phones posted for auction by 138 individual sellers. The main finding is that sellers who have acquired a free identification from Huuto.net achieve a hefty increase in the final sales price. Sellers who have not established an online reputation achieve considerably lower closing prices at auction. An increase in negative feedback points reduces the final sales price. Purchasing display-enhancing promotional options does not increase the price but may improve probability of sale. Establishing reputation, avoiding negative feedback, and acquiring identification pay off. The promotional options associated with fonts and colors are not worth the cost.     

Competition,Transparency, and Reciprocity: A Comparative Study of Auctions and Negotiations

The paper discusses experiments aimed at comparing multi-attribute reverse auctions and multi-bilateral negotiations for procuring goods with multiple attributes. Both exchange mechanisms involve a buyer purchasing from one of several sellers. Two types of negotiations are considered: verifiable and non-verifiable. They differ in the sellers’ knowledge of the current best offer on the table; in verifiable negotiations the best offer is automatically shown to every participant, which makes it similar to auctions. Online auctions and negotiation systems were used to study auction and negotiation processes, and the mechanisms’ efficiency. The results show that buyers did best using auctions, followed by non-verifiable and verifiable negotiations. We also looked into the differences between auctions and negotiations in terms of their duration, sellers’ and buyers’ involvement, and efficiency and conclude that the behavior of buyers and sellers cannot be explained solely on the grounds of traditional economics. It can, however, be explained on the grounds of social exchange theory and behavioral economics. In multi-bilateral negotiations competition and social behavior coexist. When transparency is introduced the social effect becomes stronger, weakening the impact of competition.     

Qualitative One-to-Many Multi-Issue Negotiation: Approximating the QVA

When there is one buyer interested in obtaining a service from one of a set of sellers, multi-attribute or multi-issue auctions can ensure an allocation that is efficient. Even when there is no transferable utility (e.g., money), a recent qualitative version of the Vickrey auction may be used, the QVA, to obtain a Pareto-efficient outcome where the best seller wins. However, auctions generally require that the preferences of at least one party participating in the auction are publicly known, while often making this information public is costly, undesirable, or even impossible. It would therefore be useful to have a method that does not impose such a requirement, but is still able to approximate the outcome of such an auction. The main question addressed here is whether the Pareto-efficient best-seller outcome in multi-issue settings without transferable utility (such as determined by the QVA) can be reasonably approximated by multi-bilateral closed negotiation between a buyer and multiple sellers. In these closed negotiations parties do not reveal their preferences explicitly, but make alternating offers. The main idea is to have multiple rounds of such negotiations. We study three different variants of such a protocol: one that restricts the set of allowed offers for both the buyer and the seller, one where the winning offer is announced after every round, and one where the sellers are only told whether they have won or not after every round. It is shown experimentally that this protocol enables agents that can learn preferences to obtain agreements that approximate the Pareto-efficient best-seller outcome as defined by the auction mechanism. We also show that the strategy that exploits such a learning capability in negotiation is robust against and dominates a Zero Intelligence strategy. It thus follows that the requirement to publicly announce preferences can be removed when negotiating parties are equipped with the proper learning capabilities and negotiate using the proposed multi-round multi-bilateral negotiation protocol.     

Strategic Implications of Reverse Auctions

ABSTRACT

A dramatic global power shift from seller to buyer is taking place in the reverse auction environment, with the value of materials purchased online expected to increase to more than $3 trillion in 2003. Techniques, opportunities, and problems associated with reverse auctions are described in the following paper. Special emphasis is given to General Electric Appliances. Companies such as General Electric Appliances have achieved large short-term cost savings and automation of traditionally labor-intensive processes. Reverse procurement auctions have had the effect of introducing information asymmetry in favor of the buyer, producing billions in cost savings. At least some short-run cost reductions may have come from vendors surrendering brand premiums. Further significant cost savings may not be possible; among other issues, long-term benefits to buyers may be mitigated if few vendors survive the migration to the reverse auction procurement environment, thus decreasing vendor competition.     

Ascending Combinatorial Auctions with Risk Averse Bidders

Ascending combinatorial auctions are being used in an increasing number of spectrum sales worldwide, as well as in other multi-item markets in procurement and logistics. Much research has focused on pricing and payment rules in such ascending auctions. However, recent game-theoretical research has shown that such auctions can even lead to inefficient perfect Bayesian equilibria with risk-neutral bidders. There is a fundamental free-rider problem without a simple solution, raising the question whether ascending combinatorial auctions can be expected to be efficient in the field. Risk aversion is arguably a significant driver of bidding behavior in high-stakes auctions. We analyze the impact of risk aversion on equilibrium bidding strategies and efficiency in a threshold problem with one global and several local bidders. Due to the underlying free-rider problem, the impact of risk-aversion on equilibrium bidding strategies of local bidders is not obvious. We characterize the necessary and sufficient conditions for the perfect Bayesian equilibria of the ascending auction mechanism to have the local bidders to drop at the reserve price. Interestingly, in spite of the free-riding opportunities of local bidders, risk-aversion reduces the scope of the non-bidding equilibrium. The results help explain the high efficiency of ascending combinatorial auctions observed in the lab.     

Competition between auctions

Even though auctions are capturing an increasing share of commerce, they are typically treated in the theoretical economics literature as isolated. That is, an auction is typically treated as a single seller facing multiple buyers or as a single buyer facing multiple sellers. In this paper, we review the state of the art of competition between auctions. We consider three different types of competition: competition between auctions, competition between formats, and competition between auctioneers vying for auction traffic. We highlight the newest experimental, statistical, and analytical methods in the analysis of competition between auctions.     

Emic and etic interpretations of engagement with a consumer-to-consumer online auction site

This paper provides emic and etic interpretations of engagement with a consumer-to-consumer (C2C) online auction site, based on in-depth interviews with buyers. The study exposes three misconceptions about online C2C auctions; that the interaction between parties occurs exclusively online, that the relation between buyers and sellers is purely transactional in nature, and that the interaction between buyers and sellers does not lead to ongoing business relationships. The paper reveals the utilitarian, hedonic and social benefits that are the bases of engagement with the auction site. Social benefits materialize for auction buyers during offline exchanges. The paper also reveals marketer incentives and structural disincentives for consumers' ongoing use of the auction site.     

The Influence of Seller,Auctioneer, and Bidder Factors on Trust in Online Auctions

A growing body of research promotes the importance of trust in the business-to-consumer e-commerce environment. However, there has been little research on consumer trust in the new frontier of consumer-to-consumer (C2C) online auctions. The current study investigates the factors that influence bidders’ trust in online auctions from seller (trust arguments), bidder (disposition to trust), and auctioneer (structural assurance and perceived Web risk) perspectives in order to provide a more comprehensive understanding of trust in the C2C environment. Laboratory experiments (manipulating the trust arguments in “about me” page) and online questionnaire surveys (measuring the subjects’ responses regarding structural assurance, perceived risk, disposition to trust, trust, and purchase intention) were conducted to collect necessary data. The results suggest that benevolent sellers significantly influence the trust of bidders. Analysis also finds that structural assurance is the most influential predictor of trust, which significantly influences a buyer's intention to purchase. In addition, disposition to trust is a significant predictor of trusting belief, whereas perceived Web risk does not predict purchase intention.     

Vettes and lemons on eBay

This paper empirically tests whether there are asymmetric information problems in the market for used Chevrolet Corvettes sold on eBay. The first test is based on a result from Akerlof (Quarterly Journal of Economics, 1970). If there is asymmetric information in the used market, bidders should place a premium on a new Corvette, all else equal. The paper finds little systematic evidence of a new car premium. The second test is based on a result from Bajari and Hortacsu (Rand Journal of Economics 34(2):329–355, 2003). If there is asymmetric information, then bidders will prefer to bid late in the auction in order to conceal their private information from other bidders. The paper fails to find evidence of more late bidding on used Corvettes relative to new Corvettes. The third test is based on the idea that if there is asymmetric information then there may be a winner’s curse problem in these auctions. The paper fails to find evidence consistent with bidders avoiding the winner’s curse. The results are not consistent with asymmetric information problems in the market for used Corvettes sold on eBay. It is not clear however, whether this result generalizes to other cars sold on eBay or cars sold in the off-line market.