Price Points and Price Rigidity

We offer new evidence on the link between price points and price rigidity using two datasets. One is a large weekly transaction price dataset, covering 29 product categories over an eight-year period from a large U.S. supermarket chain. The other is from the Internet, and includes daily prices over a two-year period for 474 consumer electronic goods covering ten product categories, from 293 different Internet retailers. Across the two datasets, we find that (i) 9 is the most frequently used price-ending for the penny, dime, dollar and the ten-dollar digits, (ii) the most common price changes are in multiples of dimes, dollars, and ten-dollars, (iii) 9-ending prices are at least 24% (and as much as 73%) less likely to change in comparison to prices ending with other digits, and (iv) the average size of the price change is higher if the price ends with 9 in comparison to non-9-ending prices. This link between price points and price rigidity is robust across a wide range of prices, products, product categories, and retail formats. We offer a behavioral explanation for the findings.Price Point; 9-Ending Price; Price Rigidity; Rational Inattention; E-Commerce

Price Points and Price Rigidity

We study the link between price points and price rigidity, using two datasets: weekly scanner data, and Internet data. We find that: “9” is the most frequent ending for the penny, dime, dollar and ten-dollar digits; the most common price changes are those that keep the price endings at “9”; 9-ending prices are less likely to change than non-9-ending prices; and the average size of price change is larger for 9-ending than non-9-ending prices. We conclude that 9-ending contributes to price rigidity from penny to dollar digits, and across a wide range of product categories, retail formats and retailers.Price Point, 9-Ending Price, Price Rigidity

Price Points and Price Rigidity

We offer new evidence on the link between price points and price rigidity using two datasets. One is a large weekly transaction price dataset, covering 29 product categories over an eight-year period from a large U.S. supermarket chain. The other is from the Internet, and includes daily prices over a two-year period for 474 consumer electronic goods covering ten product categories, from 293 different Internet retailers. Across the two datasets, we find that (i) 9 is the most frequently used price-ending for the penny, dime, dollar and the ten-dollar digits, (ii) the most common price changes are in multiples of dimes, dollars, and ten-dollars, (iii) 9-ending prices are at least 24% (and as much as 73%) less likely to change in comparison to prices ending with other digits, and (iv) the average size of the price change is higher if the price ends with 9 in comparison to non-9-ending prices. This link between price points and price rigidity is robust across a wide range of prices, products, product categories, and retail formats. We offer a behavioral explanation for the findings.

On Modeling Weak Sinks in MODPATH

Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low-resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs

Darwinian Selection and Non-existence of Nash Equilibria

We study selection acting on phenotype in a collection of agents playing local games lacking Nash equilibria. After each cycle one of the agents losing most games is replaced by a new agent with new random strategy and game partner. The network generated can be considered critical in the sense that the lifetimes of the agents is power law distributed. The longest surviving agents are those with the lowest absolute score per time step. The emergent ecology is characterized by a broad range of behaviors. Nevertheless, the agents tend to be similar to their opponents in terms of performance.Comment: 4 pages, 5 figure

Non-GNSS Smartphone Pedestrian Navigation Using Barometric Elevation and Digital Map-Matching

Pedestrian navigation in outdoor environments where global navigation satellite systems (GNSS) are unavailable is a challenging problem. Existing technologies that have attempted to address this problemoften require external reference signals or specialized hardware, the extra size,weight, power, and cost of which are unsuitable for many applications. This article presents a real-time, self-contained outdoor navigation application that uses only the existing sensors on a smartphone in conjunction with a preloaded digital elevation map. The core algorithm implements a particle filter, which fuses sensor data with a stochastic pedestrian motion model to predict the user’s position. The smartphone’s barometric elevation is then compared with the elevation map to constrain the position estimate. The system developed for this research was deployed on Android smartphones and tested in several terrains using a variety of elevation data sources. The results fromthese experiments showthe systemachieves positioning accuracies in the tens of meters that do not grow as a function of time

Virtual Khovanov homology using cobordisms

We extend Bar-Natan's cobordism based categorification of the Jones polynomial to virtual links. Our topological complex allows a direct extension of the classical Khovanov complex ($h=t=0$), the variant of Lee ($h=0,t=1$) and other classical link homologies. We show that our construction allows, over rings of characteristic two, extensions with no classical analogon, e.g. Bar-Natan's $\mathbb{Z}/2$-link homology can be extended in two non-equivalent ways. Our construction is computable in the sense that one can write a computer program to perform calculations, e.g. we have written a Mathematica based program. Moreover, we give a classification of all unoriented TQFTs which can be used to define virtual link homologies from our topological construction. Furthermore, we prove that our extension is combinatorial and has semi-local properties. We use the semi-local properties to prove an application, i.e. we give a discussion of Lee's degeneration of virtual homology.Comment: 78 pages, lots of figures, lots of typos, rewritten version, merged with arXiv:1212.0185, added referee's suggestions, to appear in J. Knot Theor. Rami

Serum posaconazole levels among haematological cancer patients taking extended release tablets is affected by body weight and diarrhoea: single centre retrospective analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111982/1/myc12339.pd