The Bidder's Curse

We employ a novel approach to identify overbidding in the field. We compare auction prices to fixed prices for the same item on the same webpage. In detailed board-game data, 42 percent of auctions exceed the simultaneous fixed price. The result replicates in a broad cross-section of auctions (48 percent). A small fraction of overbidders, 17 percent, suffices to generate the overbidding. The observed behavior is inconsistent with rational behavior, even allowing for uncertainty and switching costs, since also the expected auction price exceeds the fixed price. Limited attention to outside options is most consistent with our results.

The Dynamics of Seller Reputation: Theory and Evidence from eBay

We propose a basic theoretical model of eBay's reputation mechanism, derive a series of implications and empirically test their validity. Our theoretical model features both adverse selection and moral hazard. We show that when a seller receives a negative rating for the first time his reputation decreases and so does his effort level. This implies a decline in sales and price; and an increase in the rate of arrival of subsequent negative feedback. Our model also suggests that sellers with worse records are more likely to exit (and possibly re-enter under a new identity), whereas better sellers have more to gain from buying a reputation' by building up a record of favorable feedback through purchases rather than sales. Our empirical evidence, based on a panel data set of seller feedback histories and cross-sectional data on transaction prices collected from eBay is broadly consistent with all of these predictions. An important conclusion of our results is that eBay's reputation system gives way to strategic responses from both buyers and sellers.

Economic Insights from Internet Auctions: A Survey

This paper surveys recent studies of Internet auctions. Four main areas of research are summarized. First, economists have documented strategic bidding in these markets and attempted to understand why sniping, or bidding at the last second, occurs. Second, some researchers have measured distortions from asymmetric information due, for instance, to the winner's curse. Third, we explore research about the role of reputation in online auctions. Finally, we discuss what Internet auctions have to teach us about auction design.

Learning from Seller Experiements in Online Markets

The internet has dramatically reduced the cost of varying prices, dis- plays and information provided to consumers, facilitating both active and passive experimentation. We document the prevalence of targeted pricing and auction design variation on eBay, and identify hundreds of thousands of experiments con- ducted by sellers across a wide array of retail products. We show how this type of data can be used to address questions about consumer behavior and market outcomes, and provide illustrative results on price dispersion, the frequency of over-bidding, the choice of reserve prices, ?buy now?options and other auction design parameters, and on consumer sensitivity to shipping fees. We argue that leveraging the experiments of market participants takes advantage of the scale and heterogeneity of online markets and can be a powerful approach for testing and measurement.

The Price of "Man" and "Woman": A Hedonic Pricing Model of Avatar Attributes in a Synthetic World

This paper explores a unique new source of social valuation: a market for bodies. The internet hosts a number of large synthetic worlds which users can visit by piloting a computer-generated body, known as an avatar. Avatars can have an asset value, in that users can spend time to increase their skills; these asset values can be directly observed in online markets. Auction data for avatars from the synthetic fantasy world of EverQuest are used here to explore a number of questions, especially those involving the relative value of male and female avatars. In EverQuest, about 20 percent of the avatar population is female, and there are no sex-based differences in avatar capabilities. Many avatars (about one-fourth to one-fifth of the population) are cross-gendered, being piloted by a person of the opposite sex. Nonetheless, relations between avatars are gender-based, and include chivalry, dating, and sex. Female avatars tend to be concentrated in highly sexualized Human and Elven races, with very few being present among such aesthetically-challenged races as Ogres and Trolls. Hedonic analysis of the auction price data suggests that gender labels are a less important determinant of avatar values than the ‘level,’ a game-design metric that indicates the overall capabilities of the avatar. Thus, ability seems more important than sex in determining the value of a body. Nonetheless, among comparable avatars, females do sell at a significant price discount. The average avatar price is 333 dollar; the price discount for females is 40 to 55 dollar, depending on methods. The discount may stem from a number of causes, including discrimination in Earth society, the maleness of the EverQuest player base, or differences in well-being related to male and female courtship roles. We do know, however, that these differences cannot be caused by sex-based differences in the abilities of the body, since in the fantasy world of Norrath, there are none.synthetic worlds, internet auctions avatar attributes, sexual discrimination

The Economics of Internet Markets

The internet has facilitated the creation of new markets characterized by large scale, increased customization, rapid innovation and the collection and use of detailed consumer and market data. I describe these changes and some of the economic theory that has been useful for thinking about online advertising markets, retail and business-to-business e-commerce, internet job matching and financial exchanges, and other internet platforms. I also discuss the empirical evidence on competition and consumer behavior in internet markets and some directions for future research.internet, market, innovation, advertising, retail, e-commerce, financial exchanges

Seller Strategies on eBay

This paper analyzes seller characteristics and choices in approximately 1000 eBay auctions for a particular model of PDA. Seller characteristics include frequency of selling, reputation, and the qualities of the product sold. Seller choices include the length of the auction, information provided about the product, starting price, and whether to use a ‘Buy it Now’ option. We find that different types of sellers pursue systematically different strategies for how their items are offered, and we discuss the possible causes of these differences. For example, the two high volume sellers in our sample always use a combination of a ‘Buy it Now’ with a low starting price, while the many less frequent sellers use an array of pricing strategies. In addition, more highly rated sellers were somewhat more likely to provide more detailed product information, as well as secure payment options.

Pricing average price advertising options when underlying spot market prices are discontinuous

Advertising options have been recently studied as a special type of guaranteed contracts in online advertising, which are an alternative sales mechanism to real-time auctions. An advertising option is a contract which gives its buyer a right but not obligation to enter into transactions to purchase page views or link clicks at one or multiple pre-specified prices in a specific future period. Different from typical guaranteed contracts, the option buyer pays a lower upfront fee but can have greater flexibility and more control of advertising. Many studies on advertising options so far have been restricted to the situations where the option payoff is determined by the underlying spot market price at a specific time point and the price evolution over time is assumed to be continuous. The former leads to a biased calculation of option payoff and the latter is invalid empirically for many online advertising slots. This paper addresses these two limitations by proposing a new advertising option pricing framework. First, the option payoff is calculated based on an average price over a specific future period. Therefore, the option becomes path-dependent. The average price is measured by the power mean, which contains several existing option payoff functions as its special cases. Second, jump-diffusion stochastic models are used to describe the movement of the underlying spot market price, which incorporate several important statistical properties including jumps and spikes, non-normality, and absence of autocorrelations. A general option pricing algorithm is obtained based on Monte Carlo simulation. In addition, an explicit pricing formula is derived for the case when the option payoff is based on the geometric mean. This pricing formula is also a generalized version of several other option pricing models discussed in related studies.Comment: IEEE Transactions on Knowledge and Data Engineering, 201