Advertising for attention in a consumer search model

We model the idea that when consumers search for products, they first visit the firm whose advertising is more salient. The gains a firm derives from being visited early increase in search costs, so equilibrium advertising increases as search costs rise. This may result in lower firm profits when search costs increase. We extend the basic model by allowing for firm heterogeneity in advertising costs. Firms whose advertising is more salient and therefore raise attention more easily charge lower prices in equilibrium and obtain higher profits. As advertising cost asymmetries increase, aggregate profits increase, advertising falls and welfare increases.Advertising; attention; consumer search; saliency;

Comparison of the Nucleophilicities of Alkynes and Alkenes. Quantitative Determination of the Nucleophilicities of Alkynes toward Carbenium Ions

Relative reactivities of alkenes and alkynes toward diarylmethyl cations have been determined by direct rate measurements and by competition experiments in dichloromethane. At -70°C alkynes are found to be one to two orders of magnitude less reactive than analogously substituted alkenes (e.g. phenylacetylene/styrene), but the reactivity difference reduces strongly as the temperature is raised. The stereochemistry of the vinyl chlorides produced by addition of benzhydryl chlorides to alkynes is characterized

Electrically controllable magnetism in twisted bilayer graphene

Twisted graphene bilayers develop highly localised states around AA-stacked regions for small twist angles. We show that interaction effects may induce either an antiferromagnetic (AF) and a ferromagnetic (F) polarization of said regions, depending on the electrical bias between layers. Remarkably, F-polarised AA regions under bias develop spiral magnetic ordering, with a relative $120^\circ$ misalignment between neighbouring regions due to a frustrated antiferromagnetic exchange. This remarkable spiral magnetism emerges naturally without the need of spin-orbit coupling, and competes with the more conventional lattice-antiferromagnetic instability, which interestingly develops at smaller bias under weaker interactions than in monolayer graphene, due to Fermi velocity suppression. This rich and electrically controllable magnetism could turn twisted bilayer graphene into an ideal system to study frustrated magnetism in two dimensions, with interesting potential also for a range of applications.Comment: 7 pages, 3 figures. Minor correction

Consumer search costs and the incentives to merge under Bertrand Competition

This paper studies the incentives to merge in a Bertrand competition model where firms sell differentiated products and consumers search the market for satisfactory deals. In the pre-merger market equilibrium, all firms look alike and so the probability a firm is next in the queue consumers follow when visiting firms is equal across non-visited firms. However, after a merger, insiders raise their prices more than the outsiders, so consumers search for good deals first at the non-merging stores and only then, if they do not find any product satisfactory enough, at the merging stores. When search cost are negligible, the results of Deneckere and Davidson (1985) hold. However, as search costs increase, the merging firms receive fewer customers, so mergers become unprofitable for sufficiently large search costs. This new merger paradox is more likely the higher the number of non-merging firms.mergers; search; insiders; outsiders; order of search;

La teoría crítica de la resonancia de Hartmut Rosa frente a la aceleración: ¿Más allá del paternalismo y del totalitarismo?

Con su teoría crítica de la resonancia, Hartmut Rosa ha propuesto las bases de un modelo para evaluar normativamente y afrontar en la práctica las consecuencias de la aceleración social y su inherente tendencia al crecimiento y la innovación. Dicho modelo ha supuesto una bocanada de aire fresco en la Teoría Crítica para reflexionar sobre una dinámica que atraviesa la práctica totalidad de las actividades sociales. No obstante, también ha sido asociado a determinadas características que podrían hacerlo merecedor de dos calificativos siempre reprobados por la Teoría Crítica: el paternalismo y el totalitarismo. Con el fin de contribuir a los debates suscitados por el trabajo de Rosa, la pretensión de este artículo es mostrar el modo en que su planteamiento logra sortear esas posibles acusaciones al apoyarse especialmente en el concepto de Weltbeziehung [relaciones con el mundo

Hartmut Rosa’s Critical Theory of Resonance versus Acceleration: Beyond Paternalism and Totalitarianism?

With his critical theory of resonance, Hartmut Rosa has proposed the basis of a model for normatively criticizing and practically facing the consequences of social acceleration, and its inherent tendency towards growth and innovation. This model has been a breath of fresh air in Critical Theory to reflect on a dynamic that can be recognizable in virtually all social activities. However, it has also been associated with certain characteristics that could make it worthy of two labels always reproached by Critical Theory: paternalism and totalitarianism. In order to contri bute to the debates raised by Rosa's work, this article seeks to show how his approach avoids these possible accusations by relying especially on the concept of Weltbeziehung [relationships with the world]

La ética ante la cinética del turismo. Aportaciones desde la teoría crítica de la resonancia de Hartmut Rosa

Esta tesis doctoral analiza el potencial de una crítica ética sobre la continua necesidad de acelerar, crecer e innovar, así como de hacer todo disponible para el turismo. La hipótesis es que la dinámica conformada por estos aspectos puede afectar a las formas de vida y menoscabar la capacidad dialógica para la resolución de conflictos de quienes se encuentran implicados o afectados por el turismo. A partir de un estudio sistemático e interdisciplinar de la cinética del turismo, esta tesis analiza la naturaleza coercitiva y cultural de sus motores aceleratorios y de sus manifestaciones, y amplía el margen de reflexión de la ética del turismo a través de la teoría crítica de la resonancia de Hartmut Rosa. Se concluye que la resonancia ofrece una base compatible con el modelo de ética procedimental exigido por el pluralismo ético y por las demandas de justicia que puede contribuir a hacer frente a los retos que la cinética plantea en el turismo a través de instituciones, prácticas sociales y modos de socialización. This doctoral thesis examines the potential of an ethical critique on the constant need for acceleration, growth and innovation, and to make everything available for tourism. The hypothesis is that the dynamics created by these aspects can affect life forms, and undermine the capacity for dialogue for conflict resolution among those involved or affected by tourism. Taking a systematic and interdisciplinary study of the kinetics of tourism as its starting point, this thesis analyses the coercive and cultural nature of the engines of its acceleration and its manifestations, and broadens the scope for reflection on the ethics of tourism through Rosa’s Resonance Critical Theory. It concludes that resonance offers foundations compatible with the model of procedural ethics required by ethical pluralism, and the demands of justice, which could help to address the challenges posed by kinetics in tourism through institutions, social practices and modes of socialization