Word of Mouth and Taste Matching: A Theory of the Long Tail

I present a model to assess the impact of demand-side factors on the concentration of sales within large product assortments. Consumers face a search problem within an assortment of horizontally differentiated products supplied by a monopolist. They may search for a product match by drawing products from the assortment or by seeking word of mouth recommendations from other consumers. Product evaluations prior to purchase and word of mouth are shown to arise endogenously, and increase the concentration of sales. I show that taste matching mechanisms such as recommender systems, which allow consumers to obtain product recommendations from others with similar preferences, reduce sales concentration by generating a long tail effect, an increase in the tail of the sales distribution. Insights are derived on the mechanisms driving concentration in artistic markets and their strategic implications for the firm. The model is suited for experience good markets such as music, cinema, literature and video game entertainment

Word of Mouth and Taste Matching: A Theory of the Long Tail

I present a model to assess the impact of demand-side factors on the concentration of sales within large product assortments. Consumers face a search problem within an assortment of horizontally differentiated products supplied by a monopolist. They may search for a product match by drawing products from the assortment or by seeking word of mouth recommendations from other consumers. Product evaluations prior to purchase and word of mouth are shown to arise endogenously, and increase the concentration of sales. I show that taste matching mechanisms such as recommender systems, which allow consumers to obtain product recommendations from others with similar preferences, reduce sales concentration by generating a long tail effect, an increase in the tail of the sales distribution. Insights are derived on the mechanisms driving concentration in artistic markets and their strategic implications for the firm. The model is suited for experience good markets such as music, cinema, literature and video game entertainment

Neurogenetics of Dynamic Connectivity Patterns Associated With Obsessive-Compulsive Symptoms in Healthy Children

Obsessive-compulsive symptoms (OCSs) during childhood predispose to obsessive-compulsive disorder and have been associated with changes in brain circuits altered in obsessive-compulsive disorder samples. OCSs may arise from disturbed glutamatergic neurotransmission, impairing cognitive oscillations and promoting overstable functional states. A total of 227 healthy children completed the Obsessive Compulsive Inventory-Child Version and underwent a resting-state functional magnetic resonance imaging examination. Genome-wide data were obtained from 149 of them. We used a graph theory-based approach and characterized associations between OCSs and dynamic functional connectivity (dFC). dFC evaluates fluctuations over time in FC between brain regions, which allows characterizing regions with stable connectivity patterns (attractors). We then compared the spatial similarity between OCS-dFC correlation maps and mappings of genetic expression across brain regions to identify genes potentially associated with connectivity changes. In post hoc analyses, we investigated which specific single nucleotide polymorphisms of these genes moderated the association between OCSs and patterns of dFC. OCSs correlated with decreased attractor properties in the left ventral putamen and increased attractor properties in (pre)motor areas and the left hippocampus. At the specific symptom level, increased attractor properties in the right superior parietal cortex correlated with ordering symptoms. In the hippocampus, we identified two single nucleotide polymorphisms in glutamatergic neurotransmission genes (GRM7, GNAQ) that moderated the association between OCSs and attractor features. We provide evidence that in healthy children, the association between dFC changes and OCSs may be mapped onto brain circuits predicted by prevailing neurobiological models of obsessive-compulsive disorder. Moreover, our findings support the involvement of glutamatergic neurotransmission in such brain network changes

PANACEA English automatically acquired lexicon for ENV domain: Subcategorization Frames and Lexical Semantic classes for nouns

This is a domain-specific lexicon for English for environment (ENV) domain. This lexicon contain both, subcategorization frames for verbs and lexical semantic classes for nouns. This lexicon has been automatically created using PANACEA webservices using crawled data. The crawled data was obtained crawling web pages that were automatically detected to be in the English language and were automatically classified as relevant to the ENV domain. Data collection took place in the summer of 2011

Bill Zu and seminar participants at Darden School of Management

Abstract If there are diseconomies of scale in asset management, any predictability in mutual fund performance will be arbitraged away by rational investors seeking funds with the highest expected performance JEL codes: G2; G23

MenRoles project

"MenRoles project", es el sitio web del proyecto de investigación homónimo. Su grupo de investigación, está formado: Investigadora principal: Teresa Martín-García. Equipo de investigación: Teresa-Castro Martín, Julia Cordero, Clara Cortina Trilla, Irene Lapuerta, Pau Marí-Klose. Grupo de trabajo:Wanda Cabella, Nicole Hiekel, Benoît Laplant, Manuela Naldini, Ignacio Pardo, Marta Séiz, Cristina Solera.In recent decades, the new social role of women, female educational advancement, and the gradual weakening of men in the labor market, exacerbated by the current financial and economic crisis, have strongly affected men’s identities and roles and their educational, labor, conjugal and reproductive trajectories. This project assesses, on the one hand, gender differences in demographic and family dynamics.Peer reviewe

A meta-analysis of epigenome-wide association studies on pregnancy vitamin B12 concentrations and offspring DNA methylation

Circulating vitamin B12 concentrations during pregnancy are associated with offspring health. Foetal DNA methylation changes could underlie these associations. Within the Pregnancy And Childhood Epigenetics Consortium, we meta-analysed epigenome-wide associations of circulating vitamin B12 concentrations in mothers during pregnancy (n = 2,420) or cord blood (n = 1,029), with cord blood DNA methylation. Maternal and newborn vitamin B12 concentrations were associated with DNA methylation at 109 and 7 CpGs, respectively (False Discovery Rate P-valu

Additional file 5: of The emerging landscape of dynamic DNA methylation in early childhood

List of age differential Methylation Quantitative Trait Locus in early childhood (XLSX 336 kb

Additional file 3: of The emerging landscape of dynamic DNA methylation in early childhood

Age-differential methylation sites in early childhood (XLSX 2094 kb