Reserve Price in Search Models

Search models are used in a variety of fields. One of those is consumer search and in it the Stahl model is one of the most popular search models. The literature in search models concentrates mainly on equilibria with a consumer reserve price. This is a simplifying condition, which narrows down severely the freedom of the consumer. For example, once the model has a finite number of sellers who select different strategies a situation may arise where reserve price may not exist. This paper addresses the possibility of equilibria without reserve price, when sellers can use asymmetric strategies. Here a condition is given which ensures existence of reserve price in all equilibria. The condition involves prices where sellers set mass points, and undercutting those prices. The condition states that if a searcher is satisfied with such price, she should be satisfied also when a small discount is offered to that price. Assuming this, it is possible to concentrate only on equilibria with reserve price, and investigate also situations where the sellers are heterogeneous, or equilibria are not symmetric

Consumer Search with Chain Stores

The Stahl model is one of the most applied consumer search models, with many applications and an empirical background. The present paper explores an extension where sellers have asymmetries, which is mostly excluded by the literature. Sellers with heterogeneous numbers of stores are introduced, reflecting a typical market structure. As in the original Stahl model, a market consists of several sellers, and consumers, where some face a cost when sequentially searching. The paper shows that no symmetric Nash equilibrium exists in the extension. Additional results suggest that smallest sellers will be the ones offering the lowest prices, in line with several real world examples provided in the paper. However, profits remain in most cases fixed per store, making a larger firm more profitable, yet with lower quantity sold. The findings suggest that on some level price dispersion will still exist, together with some level of price stickiness, both observed in reality

Minimum Price in Search Model

This paper investigates the effects of a low bound price. To do so, a popular and empirically proven model (Stahl (89') [11]) is used. The model is extended to include an exogenously given bound on prices sellers can offer, excluding prices below such bound. The finding are rather surprising - when the bound is set sufficiently high expected price offered (EPO) by sellers drops significantly. The result seem to be robust in the parameters of the model, and driven by the information provided to consumers by such legislation step: when the limitation is set at sufficiently high levels all consumers anticipate the bound price, and searchers reject any price above it. As a result sellers offer the bound price as a pure strategy

Greediness and Equilibrium in Congestion Games

Rosenthal (1973) introduced the class of congestion games and proved that they always possess a Nash equilibrium in pure strategies. Fotakis et al. (2005) introduce the notion of a greedy strategy tuple, where players sequentially and irrevocably choose a strategy that is a best response to the choice of strategies by former players. Whereas the former solution concept is driven by strong assumptions on the rationality of the players and the common knowledge thereof, the latter assumes very little rationality on the players' behavior. From Fotakis \cite{fotakis10} it follows that for Tree Representable congestion Games greedy behavior leads to a NE. In this paper we obtain necessary and sufficient conditions for the equivalence of these two solution concepts. Such equivalence enhances the viability of these concepts as realistic outcomes of the environment. The conditions for such equivalence to emerge for monotone symmetric games is that the strategy set has a tree-form, or equivalently is a `extension-parallel graph'.Comment: 17 page

Driving Style: How Should an Automated Vehicle Behave?

This article reports on a study to investigate how the driving behaviour of autonomous vehicles influences trust and acceptance. Two different designs were presented to two groups of participants (n = 22/21), using actual autonomously driving vehicles. The first was a vehicle programmed to drive similarly to a human, “peeking” when approaching road junctions as if it was looking before proceeding. The second design had a vehicle programmed to convey the impression that it was communicating with other vehicles and infrastructure and “knew” if the junction was clear so could proceed without ever stopping or slowing down. Results showed non-significant differences in trust between the two vehicle behaviours. However, there were significant increases in trust scores overall for both designs as the trials progressed. Post-interaction interviews indicated that there were pros and cons for both driving styles, and participants suggested which aspects of the driving styles could be improved. This paper presents user information recommendations for the design and programming of driving systems for autonomous vehicles, with the aim of improving their users’ trust and acceptance

‘Urban & Suburban Nature Interactions’, Impacts and Serendipitous Narratives of The My Naturewatch Project

The My Naturewatch project uses self-build wildlife cameras supporting new public engagements with nature & technology. The project used Open Design methods providing self-defined, bespoke making outputs, modelling ‘environmental citizenship’, transitioning beyond sustainability. By codesigning makers were encouraged to engage with ecosystems refocusing human habitats & perspectives driven by curiosity. The article shares a qualitative evaluation of the project’s impact on participants, describing attitudes, understanding and behaviour towards technology & nature changed by participation

Engaging without over-powering: A case study of a FLOSS project

This is the post-print version of the published chapter. The original publication is available at the link below. Copyright @ 2010 IFIP International Federation for Information Processing.The role of Open Source Software (OSS) in the e-learning business has become more and more fundamental in the last 10 years, as long as corporate and government organizations have developed their educational and training programs based on OSS out-of-the-box tools. This paper qualitatively documents the decision of the largest UK e-learning provider, the Open University, to adopt the Moodle e-learning system, and how it has been successfully deployed in its site after a multi-million investment. A further quantitative study also provides evidence of how a commercial stakeholder has been engaged with, and produced outputs for, the Moodle community. Lessons learned from this experience by the stakeholders include the crucial factors of contributing to the OSS community, and adapting to an evolving technology. It also becomes evident how commercial partners helped this OSS system to achieve the transition from an “average” OSS system to a successful multi-site, collaborative and community-based OSS project

On the perceptual aesthetics of interactive objects

In this paper we measured the aesthetics of interactive objects (IOs), which are three-dimensional physical artefacts that exhibit autonomous behaviour when ‎handled. The aim of the research was threefold: firstly, to investigate whether aesthetic preference for distinctive objects' structures emerges in compound stimulation; secondly, to explore whether there exists aesthetic preference for distinctive objects’ behaviours; and lastly, to test whether there exists aesthetic preference for specific combinations of objects' structures and behaviours. The following variables were systematically manipulated: 1) IOs’ contour (rounded vs. angular); 2) IOs’ size (small vs. large); 3) IOs’ surface texture (rough vs. smooth); and 4) IOs’ behaviour (Lighting, Sounding, Vibrating, and Quiescent). Results show that behaviour was the dominant factor: it influenced aesthetics more than any other characteristic; Vibrating IOs were preferred over Lighting and Sounding IOs, supporting the importance of haptic processing in aesthetics. Results did not confirm the size and smoothness effects previously reported in vision and touch respectively, which suggests that for the aesthetics preference that emerges in isolated conditions may be different in compound stimulation. Finally, results corroborate the smooth curvature effect