Documents disponibles écrits par cet auteur

Cooperation Without Enforcement? / Yannis Bakos in Management science, Vol. 57 N° 11 (Novembre 2011) 

Public ISBD [article]  in Management science > Vol. 57 N° 11 (Novembre 2011) . - pp. 1944-1962 Titre : Cooperation Without Enforcement? : A Comparative Analysis of Litigation and Online Reputation as Quality Assurance Mechanisms Type de document : texte imprimé Auteurs : Yannis Bakos, Auteur ; Chrysanthos Dellarocas, Auteur Année de publication : 2012 Article en page(s) : pp. 1944-1962 Note générale : Management Langues : Anglais (eng) Mots-clés : Reputation  Litigation  Reputation  and  litigation  trade-off  Reputation  in  markets  Private  ordering  Reputation  and  adverse  selection  Litigation  and  moral  hazard Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : Commerce depends on buyers and sellers fulfilling their contractual obligations; mechanisms inducing such performance are essential to well-functioning markets. Internet-enabled reputation mechanisms that collect and disseminate consumer feedback have emerged as prominent means for inducing seller performance in online and offline markets. This paper compares the ability of reputation and more traditional litigation-like mechanisms for dispute resolution to induce efficient economic outcomes. We use a game-theoretic formulation and derive results for their relative efficiency and effectiveness individually or as complements. We find that the popular view of reputation as an efficient and relatively costless way to induce seller effort under all circumstances is incorrect; reputation is less efficient than litigation in inducing any given level of effort. Thus, reputation improves efficiency only in settings where the high cost of litigation, insufficient damage levels, or low court accuracy induce suboptimal effort or cause market failure. When adverse selection is important, reputation helps reveal the true types of market participants, which may offset its higher cost of inducing effort. Finally, adding reputation to existing litigation mechanisms increases seller effort and may require adjusting damage awards to avoid inducing excessive effort that reduces economic efficiency. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/57/11/1944.abstract [article] Cooperation Without Enforcement? : A Comparative Analysis of Litigation and Online Reputation as Quality Assurance Mechanisms [texte imprimé] / Yannis Bakos, Auteur ; Chrysanthos Dellarocas, Auteur . - 2012 . - pp. 1944-1962. Management Langues : Anglais (eng) in Management science > Vol. 57 N° 11 (Novembre 2011) . - pp. 1944-1962 Mots-clés : Reputation  Litigation  Reputation  and  litigation  trade-off  Reputation  in  markets  Private  ordering  Reputation  and  adverse  selection  Litigation  and  moral  hazard Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : Commerce depends on buyers and sellers fulfilling their contractual obligations; mechanisms inducing such performance are essential to well-functioning markets. Internet-enabled reputation mechanisms that collect and disseminate consumer feedback have emerged as prominent means for inducing seller performance in online and offline markets. This paper compares the ability of reputation and more traditional litigation-like mechanisms for dispute resolution to induce efficient economic outcomes. We use a game-theoretic formulation and derive results for their relative efficiency and effectiveness individually or as complements. We find that the popular view of reputation as an efficient and relatively costless way to induce seller effort under all circumstances is incorrect; reputation is less efficient than litigation in inducing any given level of effort. Thus, reputation improves efficiency only in settings where the high cost of litigation, insufficient damage levels, or low court accuracy induce suboptimal effort or cause market failure. When adverse selection is important, reputation helps reveal the true types of market participants, which may offset its higher cost of inducing effort. Finally, adding reputation to existing litigation mechanisms increases seller effort and may require adjusting damage awards to avoid inducing excessive effort that reduces economic efficiency. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/57/11/1944.abstract

Double marginalization in performance - based advertising / Chrysanthos Dellarocas in Management science, Vol. 58 N° 6 (Juin 2012) 

Public ISBD [article]  in Management science > Vol. 58 N° 6 (Juin 2012) . - pp.1178-1195 Titre : Double marginalization in performance - based advertising : Implications and solutions Type de document : texte imprimé Auteurs : Chrysanthos Dellarocas, Auteur Année de publication : 2012 Article en page(s) : pp.1178-1195 Langues : Anglais (eng) Mots-clés : Information  systems  Digital  marketing  Advertising  Electronic  markets  and  auctions  Electronic  commerce  Sponsored  search  Keyword  auctions Résumé : An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-per-impression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are becoming the predominant method of selling advertising on the Internet. Well-known examples include pay-per-click, pay-per-call, and pay-per-sale. This work highlights an important, and hitherto unrecognized, side effect of PPA advertising. I find that, if the prices of advertised goods are endogenously determined by advertisers to maximize profits net of advertising expenses, PPA mechanisms induce firms to distort the prices of their goods (usually upward) relative to prices that would maximize profits in settings where advertising is sold under pay-per-exposure methods. Upward price distortions reduce both consumer surplus and the joint publisher–advertiser profit, leading to a net reduction in social welfare. They persist in current auction-based PPA mechanisms, such as the ones used by Google, Yahoo!, and Microsoft. In the latter settings they also reduce publisher revenues relative to pay-per-exposure methods. I show that these phenomena constitute a form of double marginalization and discuss a number of enhancements to today's PPA mechanisms that restore equilibrium pricing of advertised goods to efficient levels, improving both consumer surplus as well as the publisher's expected profits. Note de contenu : Management ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/early/2012/03/09/mnsc.1110.1474.abstra [...] [article] Double marginalization in performance - based advertising : Implications and solutions [texte imprimé] / Chrysanthos Dellarocas, Auteur . - 2012 . - pp.1178-1195. Langues : Anglais (eng) in Management science > Vol. 58 N° 6 (Juin 2012) . - pp.1178-1195 Mots-clés : Information  systems  Digital  marketing  Advertising  Electronic  markets  and  auctions  Electronic  commerce  Sponsored  search  Keyword  auctions Résumé : An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-per-impression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are becoming the predominant method of selling advertising on the Internet. Well-known examples include pay-per-click, pay-per-call, and pay-per-sale. This work highlights an important, and hitherto unrecognized, side effect of PPA advertising. I find that, if the prices of advertised goods are endogenously determined by advertisers to maximize profits net of advertising expenses, PPA mechanisms induce firms to distort the prices of their goods (usually upward) relative to prices that would maximize profits in settings where advertising is sold under pay-per-exposure methods. Upward price distortions reduce both consumer surplus and the joint publisher–advertiser profit, leading to a net reduction in social welfare. They persist in current auction-based PPA mechanisms, such as the ones used by Google, Yahoo!, and Microsoft. In the latter settings they also reduce publisher revenues relative to pay-per-exposure methods. I show that these phenomena constitute a form of double marginalization and discuss a number of enhancements to today's PPA mechanisms that restore equilibrium pricing of advertised goods to efficient levels, improving both consumer surplus as well as the publisher's expected profits. Note de contenu : Management ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/early/2012/03/09/mnsc.1110.1474.abstra [...]

Vertically differentiated simultaneous vickrey auctions / Ravi Bapna in Management science, Vol. 56 N° 7 (Juillet 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 7 (Juillet 2010) . - pp. 1074-1092 Titre : Vertically differentiated simultaneous vickrey auctions : Theory and experimental evidence Type de document : texte imprimé Auteurs : Ravi Bapna, Auteur ; Chrysanthos Dellarocas, Auteur ; Sarah Rice, Auteur Année de publication : 2010 Article en page(s) : pp. 1074-1092 Note générale : Management Langues : Anglais (eng) Mots-clés : Competing  auctions  Simultaneous  auctions  Vertical  differentiation  Reputation  Game  theory  Laboratory  experiment Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study settings where a number of sellers simultaneously offer vertically differentiated Vickrey auctions for imperfect substitute goods to unit-demand buyers. Vertical differentiation can arise from differences in item quality, item value certainty, seller reliability, or a combination of these factors. We characterize the form of the bidding equilibria and derive expressions for the corresponding allocative efficiency and expected seller revenue. When bidders are restricted to submit at most one bid, our theory predicts the existence of a unique Bayes-Nash equilibrium that resembles a form of probabilistic “mating-of-likes.” Allowing unit-demand bidders to place an arbitrary number of bids induces complex strategy profiles where bidders place positive bids in all available auctions. Higher bidder types tend to follow more targeted strategies, focusing their “serious” bids on fewer and, generally, higher quality auctions. The nature of the bidding equilibria introduces allocative inefficiencies that arise from the lack of coordination in auction selection among bidders. We test our theoretical propositions in a controlled laboratory experiment while also utilizing a domain specific risk score to help assess how the bidders' risk type affects their bidding behavior. In support of our theory we find evidence of a probabilistic assortative matching between bidder and auction types. We also find that low risk type bidders tend to crowd on the highest auction and will pay a premium for the certainty it offers, whereas high risk type bidders fail to appropriately adjust for risk associated with the lowest auction, leading to overbidding. These lead to an interesting focal anomaly whereby bids are concentrated on the highest and lowest auctions, bypassing intermediate auctions. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/7.toc [article] Vertically differentiated simultaneous vickrey auctions : Theory and experimental evidence [texte imprimé] / Ravi Bapna, Auteur ; Chrysanthos Dellarocas, Auteur ; Sarah Rice, Auteur . - 2010 . - pp. 1074-1092. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 7 (Juillet 2010) . - pp. 1074-1092 Mots-clés : Competing  auctions  Simultaneous  auctions  Vertical  differentiation  Reputation  Game  theory  Laboratory  experiment Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We study settings where a number of sellers simultaneously offer vertically differentiated Vickrey auctions for imperfect substitute goods to unit-demand buyers. Vertical differentiation can arise from differences in item quality, item value certainty, seller reliability, or a combination of these factors. We characterize the form of the bidding equilibria and derive expressions for the corresponding allocative efficiency and expected seller revenue. When bidders are restricted to submit at most one bid, our theory predicts the existence of a unique Bayes-Nash equilibrium that resembles a form of probabilistic “mating-of-likes.” Allowing unit-demand bidders to place an arbitrary number of bids induces complex strategy profiles where bidders place positive bids in all available auctions. Higher bidder types tend to follow more targeted strategies, focusing their “serious” bids on fewer and, generally, higher quality auctions. The nature of the bidding equilibria introduces allocative inefficiencies that arise from the lack of coordination in auction selection among bidders. We test our theoretical propositions in a controlled laboratory experiment while also utilizing a domain specific risk score to help assess how the bidders' risk type affects their bidding behavior. In support of our theory we find evidence of a probabilistic assortative matching between bidder and auction types. We also find that low risk type bidders tend to crowd on the highest auction and will pay a premium for the certainty it offers, whereas high risk type bidders fail to appropriately adjust for risk associated with the lowest auction, leading to overbidding. These lead to an interesting focal anomaly whereby bids are concentrated on the highest and lowest auctions, bypassing intermediate auctions. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/7.toc