A multi-agent platform for auction-based allocation of loads in transportation logistics

This paper describes an agent-based platform for the allocation of loads in distributed transportation logistics, developed as a collaboration between CWI, Dutch National Center for Mathematics and Computer Science, Amsterdam and Vos Logistics Organizing, Nijmegen, The Netherlands. The platform follows a real business scenario proposed by Vos, and it involves a set of agents bidding for transportation loads to be distributed from a central depot in the Netherlands to different locations across Germany. The platform supports both human agents (i.e. transportation planners), who can bid through specialized planning and bidding interfaces, as well as automated, software agents. We exemplify how the proposed platform can be used to test both the bidding behaviour of human logistics planners, as well as the performance of automated auction bidding strategies, developed for such settings. The paper first introduces the business problem setting and then describes the architecture and main characteristics of our auction platform. We conclude with a preliminary discussion of our experience from a human bidding experiment, involving Vos planners competing for orders both against each other and against some (simple) automated strategies

Learning optimization models in the presence of unknown relations

In a sequential auction with multiple bidding agents, it is highly challenging to determine the ordering of the items to sell in order to maximize the revenue due to the fact that the autonomy and private information of the agents heavily influence the outcome of the auction. The main contribution of this paper is two-fold. First, we demonstrate how to apply machine learning techniques to solve the optimal ordering problem in sequential auctions. We learn regression models from historical auctions, which are subsequently used to predict the expected value of orderings for new auctions. Given the learned models, we propose two types of optimization methods: a black-box best-first search approach, and a novel white-box approach that maps learned models to integer linear programs (ILP) which can then be solved by any ILP-solver. Although the studied auction design problem is hard, our proposed optimization methods obtain good orderings with high revenues. Our second main contribution is the insight that the internal structure of regression models can be efficiently evaluated inside an ILP solver for optimization purposes. To this end, we provide efficient encodings of regression trees and linear regression models as ILP constraints. This new way of using learned models for optimization is promising. As the experimental results show, it significantly outperforms the black-box best-first search in nearly all settings.Comment: 37 pages. Working pape

Online advertising: analysis of privacy threats and protection approaches

Online advertising, the pillar of the “free” content on the Web, has revolutionized the marketing business in recent years by creating a myriad of new opportunities for advertisers to reach potential customers. The current advertising model builds upon an intricate infrastructure composed of a variety of intermediary entities and technologies whose main aim is to deliver personalized ads. For this purpose, a wealth of user data is collected, aggregated, processed and traded behind the scenes at an unprecedented rate. Despite the enormous value of online advertising, however, the intrusiveness and ubiquity of these practices prompt serious privacy concerns. This article surveys the online advertising infrastructure and its supporting technologies, and presents a thorough overview of the underlying privacy risks and the solutions that may mitigate them. We first analyze the threats and potential privacy attackers in this scenario of online advertising. In particular, we examine the main components of the advertising infrastructure in terms of tracking capabilities, data collection, aggregation level and privacy risk, and overview the tracking and data-sharing technologies employed by these components. Then, we conduct a comprehensive survey of the most relevant privacy mechanisms, and classify and compare them on the basis of their privacy guarantees and impact on the Web.Peer ReviewedPostprint (author's final draft

Buyer Commitment and Opportunism in the Online Market for IT Services

Companies increasingly outsource IT-related tasks using reverse auction mechanisms embedded into online marketplaces. However, a considerable proportion of auctions at these marketplaces do not result in a contract between buyer and supplier. Extant literature mostly refers to costly bidding and bid evaluation to explain this phenomenon. Another possible explanation is that because of the low entry barriers, buyers with a low commitment to exchange can use the marketplace solely for information gath-ering purposes such as price benchmarking and obtaining free consultations, having little or no intention to contract a supplier. We test this explanation by looking at how different types of costs incurred by the buyer during the sourcing process, are related to the outcome of reverse auctions in terms of contract award. We argue that higher levels of search, preparation and negotiation costs are associated with higher commitment to exchange and find that opportunistic behaviour does indeed play a part in the non-contracted projects, while committed buyers are more likely to enter into a contract with a supplier. The hypotheses are tested on a sample of 2,574 reverse auctions at a leading online marketplace for IT services and further verified across projects of different value and different levels of buyer experience. On the practical side, we recommend setting up entry barriers for buyers with a low level of commitment.IT Outsourcing;Online Markets;Opportunism;Reverse Auctions;Transaction Costs

Caveat Vendor: A Call to Reform the Scope of Rights of Withdrawal for Off-Premises Contracts Under U.S. Consumer Protection Laws with Respect to the Auction of Art

As sales of art at auction become increasingly popular and accessible, an overlooked consumer right may cause sellers of art to get “burned.” At its core, the auction process is intended to establish the price of a difficult-to-value object of art, therefore, the underlying philosophy of an auction is that sales are final. However, cooling-off rules in U.S. off-premises contracts are broad enough that auction house contracts can potentially fall within the ambit of these rules, giving rise to the consumer’s right to cancel the contract. Arguably, permitting consumers to cancel in remorse undermines the premise of an auction and may be detrimental to the market value of the artwork, the auctioneer’s business, and by extension the consumer. Cooling-off rules are ineffective in the context of art auctions because these rules were not drafted with an understanding of the mechanics of the auction process or the characteristics of the art market, including the subjective value of art. In fact, applying these rules to art transactions would be consumer protection overreach. These rules were designed to redress high pressure sales techniques used by door-to-door salesmen who cornered vulnerable consumers at home. By contrast, the relationship between an auction house and a consignor or winning bidder is very different: the balance of bargaining power favors the consumer. Further, for the auction process to be effective, the consumer cannot be permitted to walk away from the sale out of remorse. Despite some ambiguity in the U.S. legal framework, it is important to not assume that these cooling-off rules do not apply to auction house contracts. Such a mistake could extend the prescribed cooling-off period indefinitely, thus aggravating the costs of administering returns. Ultimately, the art world will be handicapped by the uncertainty of the application of these rules, therefore, the time for reform is now. It is upon stakeholders in the artworld, who have industry expertise that regulators and legislators are unlikely to have, to proactively petition the Federal Trade Commission to develop new approaches to the right to withdraw as it relates to art transactions

Linking urban consumers and rural farmers in India: A comparison of traditional and modern food supply chains

"Food supply chains are being transformed in a number of developing countries due to widespread changes in urban food demand. To better anticipate the impact of this transformation and thus assist in the design of appropriate policies, it is important to understand the changes that are occurring in these supply chains. In a case study of India, we find that overall urban consumption is increasing; the urban food basket is shifting away from staples toward high-value products; and modern market channels (modern retail, food processing, and the food service industry) are on the rise. We document differing practices in traditional and modern food supply chains and identify an agenda for future research." from authors' abstractAgricultural marketing, Market transformation, Rural-urban linkages, Globalization, Markets,

The Semantic Grid: A future e-Science infrastructure

e-Science offers a promising vision of how computer and communication technology can support and enhance the scientific process. It does this by enabling scientists to generate, analyse, share and discuss their insights, experiments and results in an effective manner. The underlying computer infrastructure that provides these facilities is commonly referred to as the Grid. At this time, there are a number of grid applications being developed and there is a whole raft of computer technologies that provide fragments of the necessary functionality. However there is currently a major gap between these endeavours and the vision of e-Science in which there is a high degree of easy-to-use and seamless automation and in which there are flexible collaborations and computations on a global scale. To bridge this practice–aspiration divide, this paper presents a research agenda whose aim is to move from the current state of the art in e-Science infrastructure, to the future infrastructure that is needed to support the full richness of the e-Science vision. Here the future e-Science research infrastructure is termed the Semantic Grid (Semantic Grid to Grid is meant to connote a similar relationship to the one that exists between the Semantic Web and the Web). In particular, we present a conceptual architecture for the Semantic Grid. This architecture adopts a service-oriented perspective in which distinct stakeholders in the scientific process, represented as software agents, provide services to one another, under various service level agreements, in various forms of marketplace. We then focus predominantly on the issues concerned with the way that knowledge is acquired and used in such environments since we believe this is the key differentiator between current grid endeavours and those envisioned for the Semantic Grid

The value of relationships : evidence from a supply shock to Kenyan rose exports

This paper provides evidence on the importance of reputation, intended as beliefs buyers hold about seller's reliability, in the context of the Kenyan rose export sector. A model of reputation and relational contracting is developed and tested. We show that 1) the value of the relationship increases with the age of the relationship; 2) during an exogenous negative supply shock sellers prioritize relationships consistently with the predictions of the model; and 3) reliability at the time of the shock positively correlates with future survival and relationship value. Models exclusively focussing on enforcement or insurance considerations cannot account for the evidence