1,895 research outputs found
When Little Things Mean a Lot: On the Inefficiency of Item Pricing Laws
Item pricing laws (IPLs) require a price tag on every item sold by a retailer. We study IPLs and assess their efficiency by quantifying their costs and comparing them to previously documented benefits. On the cost side, we posit that IPLs should lead to higher prices because they increase the cost of pricing as well as the cost of price adjustment. We test this prediction using data collected from large supermarket chains in the Tri-State area of New York, New Jersey and Connecticut, which offer a unique setting because these states vary in their use of IPLs, but otherwise offer geographical proximity with each other and similar markets, supermarket chains, and socioeconomic environments. We find that IPL store prices are higher by about 20¢–25¢ or 8.0%–9.6% per item on average, in comparison to non-IPL stores. As a control, we use data from stores that are exempt from IPL requirements (because they use electronic shelf labels), and find that their prices fall between IPL and non-IPL store prices. To assess the efficiency of IPLs, we compare these costs to existing measures of the benefits of IPLs which are based on measurements of the frequency and the magnitude of pricing errors the IPLs are supposed to prevent. We find that the costs of IPLs are an order of magnitude higher than the upper bound of these estimate benefits.Item Pricing Law; Cost of Item Pricing Law; Cost of Price Adjustment; Menu Cost; Retail Pricing;
When Little Things Mean a Lot: On the Inefficiency of Item Pricing Laws
We study item-pricing laws (which require that each item in a store be individually marked with a price sticker) and examine and quantify their costs and benefits. On the cost side, we argue that item-pricing laws increase the retailers’ costs, forcing them to raise prices. We test this prediction using data on retail prices from large supermarket chains in the Tri-State area of New York, New Jersey and Connecticut. The Tri-States offer a unique setting—a natural experiment—to study item-pricing laws because the States vary in their use of item-pricing laws, but otherwise offer similar markets and chains operating in a close proximity to each other in a relatively homogenous socioeconomic environment. We use two datasets, one emphasizing the breadth in coverage across products and the other across stores. We find consistent evidence across products, product categories, stores, chains, states, and sampling periods, that the prices at stores facing item-pricing laws are higher than the prices at stores not facing the item pricing laws by about 25¢ or 9.6% per item. We also have data from supermarket chains that would be subject to item-pricing laws but are exempted from item pricing requirement because they use costly electronic shelf label systems. Using this data as a control, we find that the electronic shelf label store prices fall between the item-pricing law and non-item- pricing law store prices: they are lower than the item-pricing law store prices by about 15¢ per item on average, but are higher than the non- item-pricing law store prices by about 10¢ per item on average. On the benefit side, we study the frequency and the magnitude of supermarket pricing errors, which the item-pricing laws are supposed to prevent. We quantify the benefits of the IPLs by conservatively assuming that they successfully accomplish their mission of preventing all price mistakes. Comparing the costs of item-pricing laws to their benefits, we find that the item-pricing law costs are at least an order of magnitude higher than the benefits.Item Pricing Laws, Costs of Item Pricing Laws, Benefits of Item Pricing Laws, Cost of Price Adjustment, Pricing Accuracy, Electronic Shelf Label System, Pricing Regulation, Cost of Pricing, Supermarket Chains
Study of Uniaxial Tensile Properties of Hexagonal Boron Nitride Nanoribbons
Uniaxial tensile properties of hexagonal boron nitride nanoribbons and
dependence of these properties on temperature, strain rate, and the inclusion
of vacancy defects have been explored with molecular dynamics simulations using
Tersoff potential. The ultimate tensile strength of pristine hexagonal boron
nitride nanoribbon of 26 nm x 5 nm with armchair chirality is found to be 100.5
GPa. The ultimate tensile strength and strain have been found decreasing with
increasing the temperature while an opposite trend has been observed for
increasing the strain rate. Furthermore, the vacancy defects reduce ultimate
tensile strength and strain where the effect of bi-vacancy is clearly
dominating over point vacancy
Fractional Conformal Map, Qubit Dynamics and the Leggett-Garg Inequality
Any pure state of a qubit can be geometrically represented as a point on the
extended complex plane through stereographic projection. By employing
successive conformal maps on the extended complex plane, we can generate an
effective discrete-time evolution of the pure states of the qubit. This work
focuses on a subset of analytic maps known as fractional linear conformal maps.
We show that these maps serve as a unifying framework for a diverse range of
quantum-inspired conceivable dynamics, including (i) unitary dynamics,(ii)
non-unitary but linear dynamics and (iii) non-unitary and non-linear dynamics
where linearity (non-linearity) refers to the action of the discrete time
evolution operator on the Hilbert space. We provide a characterization of these
maps in terms of Leggett-Garg Inequality complemented with No-signaling in Time
(NSIT) and Arrow of Time (AoT) conditions.Comment: 9 pages, 1 figur
Challenges in identifying cancer genes by analysis of exome sequencing data.
Massively parallel sequencing has permitted an unprecedented examination of the cancer exome, leading to predictions that all genes important to cancer will soon be identified by genetic analysis of tumours. To examine this potential, here we evaluate the ability of state-of-the-art sequence analysis methods to specifically recover known cancer genes. While some cancer genes are identified by analysis of recurrence, spatial clustering or predicted impact of somatic mutations, many remain undetected due to lack of power to discriminate driver mutations from the background mutational load (13-60% recall of cancer genes impacted by somatic single-nucleotide variants, depending on the method). Cancer genes not detected by mutation recurrence also tend to be missed by all types of exome analysis. Nonetheless, these genes are implicated by other experiments such as functional genetic screens and expression profiling. These challenges are only partially addressed by increasing sample size and will likely hold even as greater numbers of tumours are analysed
VLSI Architectures of Forward Kinematic Processor for Robotics Applications
This paper aims to get a comprehensive review of current-day robotic
computation technologies at VLSI architecture level. We studied several repots
in the domain of robotic processor architecture. In this work, we focused on
the forward kinematics architectures which consider CORDIC algorithms, VLSI
circuits of WE DSP16 chip, parallel processing and pipelined architecture, and
lookup table formula and FPGA processor. This study gives us an understanding
of different implementation methods for forward kinematics. Our goal is to
develop a forward kinematics processor with FPGA for real-time applications,
requires a fast response time and low latency of these devices, useful for
industrial automation where the processing speed plays a great role.Comment: 8 pages, 22 figure
Octanuclear heterobimetallic {Ni4Ln4} assemblies possessing Ln4 square grid [2×2] motifs : synthesis, structure and magnetism
Octanuclear heterobimetallic complexes, [Ln4Ni4(H3L)4(µ3-OH)4(µ2-OH)4]4Cl·xH2O·yCHCl3 (Dy3+ , x = 30.6, y = 2 (1); Tb3+ , x = 28, y = 0 (2) ; Gd3+ , x = 25.3, y = 0 (3); Ho3+ , x = 30.6, y = 3 (4)) (H5L = N1, N3-bis(6-formyl-2-(hydroxymethyl)
-4-methylphenol) diethylenetriamine) are reported. These are assembled by the cumulative coordination action of four doubly deprotonated compartmental ligands, [H3L] 2- , along with eight exogenous –OH ligands. Within the core of these complexes, four Ln3+ are distributed to the four corners of a perfect square grid while four Ni2+ are projected away from the plane of the Ln4 unit. Each of the four Ni2+ possesses distorted octahedral geometry while all the Ln3+ are crystallographically equivalent and are present in an elongated square antiprism geometry. The magnetic properties of compound 3 are dominated by an easy-plane single-ion anisotropy of the Ni2+ ions [DNi = 6.7(7) K] and dipolar interactions between Gd3+ centers. Detailed ac magnetometry reveals the presence of distinct temperature-dependent out-of-phase signals for compounds 1 and 2, indicative of slow magnetic relaxation. Magnetochemical analysis of complex 1 implies the 3d and the 4f metal ions are engaged in ferromagnetic interactions with SMM behavior, while dc magnetometry of compound 2 is suggestive of an antiferromagnetic Ni-Tb spin-exchange with slow magnetic relaxation due to a field-induced level crossing. Compound 4 exhibits an easy-plane single-ion anisotropy for the Ho3+ ions and weak interactions between spin centers
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