Dense fluidized granular media in microgravity

Handling and transport of granular media are inevitably governed by the settling of particles. Settling into a dense state is one of the defining characteristics of granular media, among dissipation and absence of thermal agitation. Hence, settling complicates the adaptation of microscopic theories from atomic, molecular, or colloidal media to granular media. It is desirable to provide experiments in which selectively one of the granular characteristics is tuned to test suitable adaptation of a theory. Here we show that gas fluidization of granular media in microgravity is a suitable approach to achieve steady states closer to thermally agitated systems free of settling. We use diffusing-wave spectroscopy to compare the spatial homogeneity and the microscopic dynamics of gas-fluidized granular media on the ground and in drop tower flights with increasing packing densities up to full arrest. The gas fluidization on the ground leads to inhomogeneous states as known from fluidized beds, and partial arrest occurs at packing fractions lower than the full arrested packing. The granular medium in microgravity in contrast attains a homogeneous state with complete mobilization even close to full arrest. Fluidized granular media thus can be studied in microgravity with dynamics and packing fractions not achievable on the ground

a mechanism design approach

We study road congestion as a mechanism design problem. In our basic model we analyze the allocation of a set of drivers among two roads, one of which may be congested. An additional driver on the congestible road imposes an externality on the other drivers by increasing their travel time. Each driver is privately informed about her value of time and asked to report that value to the mechanism designer, who assigns drivers to roads. With a finite number of drivers, there is aggregate uncertainty and the efficient allocation is ex ante unknown. Setting a single Pigouvian price is then not optimal. However, the efficient allocation is implementable by a Vickrey-Clarke-Groves price schedule that lets each driver pay the externality she imposes on other drivers. This allows drivers to pay to have other drivers use the slow road instead of the congestible road. As the number of drivers becomes large, there is a single optimal Pigouvian price that leads to an efficient allocation. However, finding this price requires the mechanism designer to either know the precise distribution of the value of time or the use of our mechanism. We analyze some extensions and apply our model to various congestion problems arising in other contexts

Understanding the impact of relationship disruptions

Personal relationships between salespeople and customers are essential for the success of business-to-business relationships, and research has shown that a change of the salesperson can severely harm financial performance. However, such interpersonal relationship disruptions may also have positive effects by encouraging vitalizing reexplorations of the relationship. Using multilevel loyalty theory and relationship life cycle theory, the authors offer a comprehensive conceptualization of potentially countervailing consequences of relationship disruptions. In particular, disruptions may have different effects on resale revenue (from previously sold products) versus new sale revenue (from newly sold products), contingent on both the history and expected future development of the relationship. Therefore, this study examines moderators on the firm-level relationship prior to disruption and salesperson relationship management afterward. Longitudinal data from 2,040 customers of an international business-to-business firm reveal that a disruption can increase overall performance by more than 29%, depending on the firm-level relationship before disruption and the new salesperson’s relationship management. Managers can use these findings proactively to evaluate and manage the risks and opportunities involved in relationship disruptions

The risky side of inspirational appeals in personal selling : when do customers infer ulterior salesperson motives?

In personal selling, the inspirational appeal (IA) is a widely promoted tactic that aims at stimulating customers' values and ideals, thereby evoking emotions and arousing their enthusiasm for a product. However, whether IAs in fact improve or undermine salespeople's success in sales talks remains controversial. Therefore, this study examines consequences and key contingencies of IAs in customer–salesperson interactions in a retailing context, using multisource data from several retailing industries for three quantitative studies, comprising a total sample of 590 customer and 174 salesperson responses. Drawing on the Multiple Inferences Model (MIM), the authors show that an IA is likely to drive the customer's inference that the salesperson holds ulterior motives. IAs seem to be particularly detrimental for salespeople with a lack of customer orientation. Beyond expanding research on influence tactics and the ambivalent role of IAs in retailing interactions, these findings can guide practitioners about when to refrain from using an IA

Tree-livestock interaction promotes nutrient shift and influences plant species richness in orchards

Orchards are traditional agroforestry elements in agricultural landscapes and valuable for nature conservation in Europe. However, their diversity is endangered due to farmland intensification or abandonment. Grazing management promotes plant species diversity but grazers are suspected to harm trees through debarking. We studied 42 orchards within the Rhenish uplands (Germany) and compared horses, cattle and sheep grazing. We analysed how grassland diversity is promoted by the presence of trees and modified by grazing management, as well as how grazers may impact trees. Plant species richness benefited from tree presence, but was not affected by tree-cover and only slightly by grazer species, whereas grazing intensity showed significant negative effects. All grazer species significantly increased recent debarking in the absence of individual tree-protection. Therefore, maintaining species diversity and long-term tree persistence in orchards does not primarily depend upon grazer species, but more especially on grazing intensity and tree-protection

Regional Housing Market Conditions in Spain

Selling homes is not easy. Home sellers usually need to apply a price discount to swiftly close a deal, and more so when housing market activity is low. Using detailed data on home listings and transactions in Spain, we provide unique estimates of the price discount across regional submarkets and time. We document that the price discount is strongly countercylical, as it increases with declining market conditions, and viceversa during upturns. Despite substantial heterogeneity, regional price discounts are synchronized and a single common factor can account for about sixty percent of their variation, thus suggesting the existence of a national housing cycle. Finally, we document that the main factors linked to changes in the price discount are developments in income, population, and interest rates, which are jointly able to explain the bulk of variation in housing market liquidity across regions and time. Besides providing a formal test of the performance of the price spread in gauging housing market liquidity, this study conveys practical information to real estate market participants, policymakers, and financial institutions for which assessing conditions in Spanish housing markets is a central task

When do customers get what they expect? Understanding the ambivalent effects of customers’ service expectations on satisfaction

Extant research established that customers’ expectations play an ambivalent role in the satisfaction formation process: While higher expectations are more difficult to meet and thus cause dissatisfaction, they simultaneously increase satisfaction via customers’ perceived performance owing to a placebo effect. However, to date, knowledge is scarce on the question under which conditions either the positive or negative effect of expectations on satisfaction prevails. Building on information processing theory, the authors hypothesize that an essential contingency of the indirect, placebo-based effect is the degree to which customers are able and motivated to process a service experience. Three studies with a total of over 4,000 customers in different service contexts provide strong evidence for this hypothesis. Thus, managers are well advised to provide a realistic or even understated prospect if the service context favors customers’ ability or motivation to evaluate. Conversely, if customers are neither able nor motivated to evaluate the service, increasing customer expectations represents a viable strategy to enhance satisfaction. Relatedly, if customers hold low service expectations, managers should foster customers’ ability and motivation to evaluate the service. In contrast, if service expectations are high, managers may benefit from reducing the likelihood that customers overly focus on the service performance