Loss Leaders: An Indirect Empirical Test

We apply an indirect method to test for the extent of loss leader pricing. Specifically, the extent of loss leader pricing should increase with the profit from other regularly-priced items. Bookstores customarily use bestsellers as loss leaders. Among conventional bookstores, we found that the bestseller discount systematically increased with the store area, selection of titles, and presence of other product categories. A one standard deviation increase in store area was associated with a 3.7 (± 1.8) higher bestseller percentage discount. Among online stores, we found that the bestseller discount systematically increased with the selection of titles and number of product categories. A one standard deviation increase in selection was associated with a 9.5 (± 2.2) higher bestseller percentage discount.retail pricing, loss leaders, switching costs

The Value of Online Information Privacy: An Empirical Investigation

Concern over online information privacy is widespread and rising. However, prior research is silent about the value of information privacy in the presence of potential benefits from sharing personally identifiable information. We analyzed individuals' trade-offs between the benefits and costs of providing personal information to websites. We found that benefits - monetary reward and future convenience - significantly affect individuals' preferences over websites with differing privacy policies. We also quantified the value of website privacy protection. Among U.S. subjects, protection against errors, improper access, and secondary use of personal information is worth US$30.49 - 44.62. Finally, we identified three distinct segments of Internet consumers - privacy guardians, information sellers, and convenience seekers.Information privacy, conjoint analysis, cost-benefit tradeoff, privacy concern, monetary reward, time-saving service

The Value of Online Information Privacy: An Empirical Investigation

Concern over online information privacy is widespread and rising. However, prior research is silent about the value of information privacy in the presence of potential benefits from sharing personally identifiable information. Analyzing individuals' trade-offs between the benefits and costs of providing personal information to websites revealed that benefits, monetary reward and future convenience, significantly affect individuals' preferences over websites with differing privacy policies. Quantifying the value of website privacy protection revealed that among U.S. subjects, protection against errors, improper access, and secondary use of personal information is worth US $30.49 - 44.62. Finally, three distinct segments of Internet consumers were determined: privacy guardians, information sellers and convenience seekers.

Noise Characteristics of the FORE+OSEM(DB) Reconstruction Method for the MiCES PET Scanner

The FORE+OSEM(DB) image reconstruction method has been proposed for the fully-3D MiCES PET scanner under construction at the University of Washington. It is based on Fourier rebinning followed by 2D OSEM and an incorporated model of detector blurring (DB). As an extension, this paper presents the noise/resolution characteristics of this method. Multiple realizations were simulated to estimate the noise properties of the algorithm. The results are compared with OSEM followed by post reconstruction 3D Gaussian smoothing. The results show that the incorporation of detector blurring (OSEM(DB)) into the system matrix improves resolution compared to OSEM, while also inducing an increased variance at all radial locations. In addition, radially-varying noise characteristics are more apparent with OSEM(DB) than with OSEM.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85836/1/Fessler204.pd

Living with multimorbidity? The lived experience of multiple chronic conditions in later life

Multimorbidity is defined biomedically as the co-existence of two or more long-term conditions in an individual. Globally, the number of people living with multiple conditions is increasing, posing stark challenges both to the clinical management of patients and the organisation of health systems. Qualitative literature has begun to address how concurrency affects the self-management of chronic conditions, and the concept of illness prioritisation predominates. In this article, we adopt a phenomenological lens to show how older people with multiple conditions experience illness. This UK study was qualitative and longitudinal in design. Sampling was purposive and drew upon an existing cohort study. In total, 15 older people living with multiple conditions took part in 27 in-depth interviews. The practical stages of analysis were guided by Constructivist Grounded Theory. We argue that the concept of multimorbidity as biomedically imagined has limited relevance to lived experience, while concurrency may also be erroneous. In response, we outline a lived experience of multiple chronic conditions in later life, which highlights differences between clinical and lay assumptions and makes the latter visible

From MinX to MinC: Semantics-Driven Decompilation of Recursive Datatypes

Reconstructing the meaning of a program from its binary executable is known as reverse engineering; it has a wide range of applications in software security, exposing piracy, legacy systems, etc. Since reversing is ultimately a search for meaning, there is much interest in inferring a type (a meaning) for the elements of a binary in a consistent way. Unfortunately existing approaches do not guarantee any semantic relevance for their reconstructed types. This paper presents a new and semantically-founded approach that provides strong guarantees for the reconstructed types. Key to our approach is the derivation of a witness program in a high-level language alongside the reconstructed types. This witness has the same semantics as the binary, is type correct by construction, and it induces a (justifiable) type assignment on the binary. Moreover, the approach effectively yields a type-directed decompiler. We formalise and implement the approach for reversing Minx, an abstraction of x86, to MinC, a type-safe dialect of C with recursive datatypes. Our evaluation compiles a range of textbook C algorithms to MinX and then recovers the original structures

The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability

Purpose: To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Methods: Thirty-nine subjects (22.1. ±. 3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16. h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Results: Lens fit assessments were not different between brands (P > 0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12. h (P 0.05). Movement-on-blink was unaffected by wear-time (F = 0.403, P = 0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r = -0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P > 0.01). Conclusions: Among the lenses tested, objective lens fit changed between 8. h and 12. h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit

Mesoscopic colonization of a spectral band

We consider the unitary matrix model in the limit where the size of the matrices become infinite and in the critical situation when a new spectral band is about to emerge. In previous works the number of expected eigenvalues in a neighborhood of the band was fixed and finite, a situation that was termed "birth of a cut" or "first colonization". We now consider the transitional regime where this microscopic population in the new band grows without bounds but at a slower rate than the size of the matrix. The local population in the new band organizes in a "mesoscopic" regime, in between the macroscopic behavior of the full system and the previously studied microscopic one. The mesoscopic colony may form a finite number of new bands, with a maximum number dictated by the degree of criticality of the original potential. We describe the delicate scaling limit that realizes/controls the mesoscopic colony. The method we use is the steepest descent analysis of the Riemann-Hilbert problem that is satisfied by the associated orthogonal polynomials.Comment: 17 pages, 2 figures, minor corrections and addition