When online sellers use different prices for different consumers

It may be more profitable for retailers to avoid personalising prices, but that may hurt consumers, writes Shota Ichihash

Data Collection by an Informed Seller

A seller faces a consumer with an uncertain value for the product. The seller has imperfect private information about the value and requests additional data to set the price. The consumer can decline any request. The consumer's willingness to provide data depends on his belief about the seller's type which in turn depends on the request. We show that the type uncertainty limits the scope of data collection: All equilibrium payoffs are spanned by fully pooling equilibria in which the seller collects the same data regardless of the type. The seller's private information lowers efficiency and profits, but benefits the consumer by fueling his skepticism and preventing excessive data collection. Having less private information may enable the seller to collect more data directly from the consumer and may lower the overall consumer welfare

Data Collection by an Informed Seller

A seller faces a consumer with an uncertain value for the product. The seller has imperfect private information about the value and requests additional data to set the price. The consumer can decline any request. The consumer’s willingness to provide data depends on his belief about the seller’s type which in turn depends on the request. We show that the type uncertainty limits the scope of data collection: All equilibrium payoffs are spanned by fully pooling equilibria in which the seller collects the same data regardless of the type. The seller’s private information lowers efficiency and profits, but benefits the consumer by fueling his skepticism and preventing excessive data collection. Having less private information may enable the seller to collect more data directly from the consumer and may lower the overall consumer welfare

Relationship Between Balance Recovery From a Forward Fall and Lower-Limb Rate of Torque Development

The authors examined the relationship between the maximum recoverable lean angle via the tether-release method with early- or late-phase rate of torque development (RTD) and maximum torque of lower-limb muscle groups in 56 young healthy adults. Maximal isometric torque and RTD at the hip, knee, and ankle were recorded. The RTD at 50-ms intervals up to 250 ms from force onset was calculated. The results of a stepwise multiple regression analysis, early RTD for hip flexion, and knee flexion were chosen as predictive variables for the maximum recoverable lean angle. The present study suggests that some of the early RTD in the lower limb muscles, but not the maximum isometric torque, can predict the maximum recoverable lean angle

Emergence and diversification of a host-parasite RNA ecosystem through Darwinian evolution

In prebiotic evolution, molecular self-replicators are considered to develop into diverse, complex living organisms. The appearance of parasitic replicators is believed inevitable in this process. However, the role of parasitic replicators in prebiotic evolution remains elusive. Here, we demonstrated experimental coevolution of RNA self-replicators (host RNAs) and emerging parasitic replicators (parasitic RNAs) using an RNA-protein replication system we developed. During a long-term replication experiment, a clonal population of the host RNA turned into an evolving host-parasite ecosystem through the continuous emergence of new types of host and parasitic RNAs produced by replication errors. The host and parasitic RNAs diversified into at least two and three different lineages, respectively, and they exhibited evolutionary arms-race dynamics. The parasitic RNA accumulated unique mutations, thus adding a new genetic variation to the whole replicator ensemble. These results provide the first experimental evidence that the coevolutionary interplay between host-parasite molecules plays a key role in generating diversity and complexity in prebiotic molecular evolution

Size Regulation and Stability Enhancement of Pt Nanoparticle Catalyst via Polypyrrole Functionalization of Carbon-Nanotube-Supported Pt Tetranuclear Complex

A novel multiwall carbon nanotube (MWCNT) and polypyrrole (PPy) composite was found to be useful for preparing durable Pt nanoparticle catalysts of highly regulated sizes. A new pyrene-functionalized Pt₄ complex was attached to the MWCNT surface which was functionalized with PPy matrix to yield Pt₄ complex/PPy/MWCNT composites without decomposition of the Pt₄ complex units. The attached Pt₄ complexes in the composite were transformed into Pt⁰ nanoparticles with sizes of 1.0–1.3 nm at a Pt loading range of 2 to 4 wt %. The Pt nanoparticles in the composites were found to be active and durable catalysts for the <i>N</i>-alkylation of aniline with benzyl alcohol. In particular, the Pt nanoparticles with PPy matrix exhibited high catalyst durability in up to four repetitions of the catalyst recycling experiment compared with nonsize-regulated Pt nanoparticles prepared without PPy matrix. These results demonstrate that the PPy matrix act to regulate the size of Pt nanoparticles, and the PPy matrix also offers stability for repeated usage for Pt nanoparticle catalysis