Product Variety, Across-Market Demand Heterogeneity, and the Value of Online Retail

Online retail gives consumers access to an astonishing variety of products. However, the additional value created by this variety depends on the extent to which local retailers already satisfy local demand. To quantify the gains and account for local demand, we use detailed data from an online retailer and propose methodology to address a common issue in such data - sparsity of local sales due to sampling and a significant number of local zeros. Our estimates indicate products face substantial demand heterogeneity across markets; as a result, we find gains from online variety that are 30% lower than previous studies

Product Variety, Across-Market Demand Heterogeneity, and the Value of Online Retail

Online retail gives consumers access to an astonishing variety of products. However, the additional value created by this variety depends on the extent to which local retailers already satisfy local demand. To quantify the gains and account for local demand, we use detailed data from an online retailer and propose methodology to address a common issue in such data - sparsity of local sales due to sampling and a significant number of local zeros. Our estimates indicate products face substantial demand heterogeneity across markets; as a result, we find gains from online variety that are 30% lower than previous studies

Product Variety, Across-Market Demand Heterogeneity, and the Value of Online Retail

Online retail gives consumers access to an astonishing variety of products. However, the additional value created by this variety depends on the extent to which local retailers already satisfy local demand. To quantify the gains and account for local demand, we use detailed data from an online retailer and propose methodology to address a common issue in such data-sparsity of local sales due to sampling and a significant number of local zeros. Our estimates indicate products face substantial demand heterogeneity across markets; as a result, we find gains from online variety that are 45% lower than previous studies

Product Variety, Across-Market Demand Heterogeneity, and the Value of Online Retail

Online retail gives consumers access to an astonishing variety of products. However, the additional value created by this variety depends on the extent to which local retailers already satisfy local demand. To quantify the gains and account for local demand, we use detailed data from an online retailer and propose methodology to address a common issue in such data-sparsity of local sales due to sampling and a significant number of local zeros. Our estimates indicate products face substantial demand heterogeneity across markets; as a result, we find gains from online variety that are 45% lower than previous studies

HrcU and HrpP are pathogenicity factors in the fire blight pathogen Erwinia amylovora required for the type III secretion of DspA/E

Table S1. Description of data: Sequences of oligonucleotide primers used in this study. (DOCX 109 kb

Interplay between Superconductivity and Antiferromagnetism in a Multi-layered System

Based on a microscopic model, we study the interplay between superconductivity and antiferromagnetism in a multi-layered system, where two superconductors are separated by an antiferromagnetic region. Within a self-consistent mean-field theory, this system is solved numerically. We find that the antiferromagnetism in the middle layers profoundly affects the supercurrent flowing across the junction, while the phase difference across the junction influences the development of antiferromagnetism in the middle layers. This study may not only shed new light on the mechanism for high-$T_{c}$ superconductors, but also bring important insights to building Josephson-junction-based quantum devices, such as SQUID and superconducting qubit.Comment: 4+ pages, 5 figures, Accepted for publication in Phys. Rev.

The Classical Limit of Quantum Mechanics and the Fejer Sum of the Fourier Series Expansion of a Classical Quantity

In quantum mechanics, the expectation value of a quantity on a quantum state, provided that the state itself gives in the classical limit a motion of a particle in a definite path, in classical limit goes over to Fourier series form of the classical quantity. In contrast to this widely accepted point of view, a rigorous calculation shows that the expectation value on such a state in classical limit exactly gives the Fej\'{e}r's arithmetic mean of the partial sums of the Fourier series

Internal R&D or external asset growth? A closer look at CEO narcissism and entrepreneurial orientation

PurposeIn today\u27s competitive business environment, understanding how leadership traits shape outcomes is critical. Chief executive officer (CEO) narcissism, an intriguing and debated trait, raises questions about its impact on organisational behaviour, particularly regarding entrepreneurial orientation (EO). This study aims to examine how CEO narcissism affects EO, both as aggregate and specific measures, encompassing internal and external growth. It also considers the organisational context by examining how factors such as capital intensity, firm ownership and CEO duality moderate this relationship.Design/methodology/approachTo test the hypotheses, the authors used a sample of firms drawn from China\u27s ChiNext database (2008–2017). After an initial screening, the final sample consists of 251 CEOs from 239 companies. Data on CEO narcissism are collected from the firm\u27s official website and major online sources, whilst additional data are extracted from the WIND daabase. The authors use multiple regression and ordinary least squares (OLS) for data analysis.FindingsThe results show that CEO narcissism leads to external asset growth investments but not internal research and development (R&D). There is a positive relationship between CEO narcissism and EO as an aggregate measure and also different managerial discretions play varying roles in the relationship. Specifically, capital intensity weakens this relationship, but state ownership strengthens it.Originality/valueThis study helps to clarify the relationship between CEO narcissism and EO and advances the literature by showing that firms\u27 EO actions may take various forms of innovation and venturing as new entry initiations of EO. The study findings have important implications for firms to capitalise on narcissistic CEOs\u27 entrepreneurial tendencies, balance internal R&D and external asset growth and leverage various managerial discretions

Spatiotemporal complexity of a ratio-dependent predator-prey system

In this paper, we investigate the emergence of a ratio-dependent predator-prey system with Michaelis-Menten-type functional response and reaction-diffusion. We derive the conditions for Hopf, Turing and Wave bifurcation on a spatial domain. Furthermore, we present a theoretical analysis of evolutionary processes that involves organisms distribution and their interaction of spatially distributed population with local diffusion. The results of numerical simulations reveal that the typical dynamics of population density variation is the formation of isolated groups, i.e., stripelike or spotted or coexistence of both. Our study shows that the spatially extended model has not only more complex dynamic patterns in the space, but also chaos and spiral waves. It may help us better understand the dynamics of an aquatic community in a real marine environment.Comment: 6pages, revtex

On the inertia of heat

Does heat have inertia? This question is at the core of a long-standing controversy on Eckart's dissipative relativistic hydrodynamics. Here I show that the troublesome inertial term in Eckart's heat flux arises only if one insists on defining thermal diffusivity as a spacetime constant. I argue that this is the most natural definition, and that all confusion disappears if one considers instead the space-dependent comoving diffusivity, in line with the fact that, in the presence of gravity, space is an inhomogeneous medium.Comment: 3 page