Bidder Collusion

Within the heterogeneous independent private values model, we analyze bidder collusion at first and second price single-object auctions, allowing for within-cartel transfers. Our primary focus is on (i) coalitions that contain a strict subset of all bidders and (ii) collusive mechanisms that do not rely on information from the auctioneer, such as the identity of the winner or the amount paid. To analyze collusion, a richer environment is required than that required to analyze non-cooperative behavior. We must account for the possibility of shill bidders as well as mechanism payment rules that may depend on the reports of cartel members or their bids at the auction. We show there are cases in which a coalition at a first price auction can produce no gain for the coalition members beyond what is attainable from non-cooperative play. In contrast, a coalition at a second price auction captures the entire collusive gain. For collusion to be effective at a first price auction we show that the coalition must submit two bids that are different but close to one another, a finding that has important empirical implicationsauctions, collusion, bidding rings, shill

Rubric scoring of a clinical test of executive functioning

Executive functions (EF) are complex abilities that allow one to successfully complete independent, deliberate, and novel goal-directed activities (Lezak, Howieson, & Loring, 2004). EF tests require solving problems with minimal direction from the examiner (Baddeley, 1992; Shallice & Burgess, 1991). Because EF skills tend to show up globally, Lezak et al. (2004) suggested clinicians will learn more about one’s EF abilities by observing how he or she goes about solving a problem than from a test score. If this is the case, a “rubric” score that took into consideration “how” a problem was solved may provide the clinician with better information for treatment planning than a test score, as long as it did not greatly affect test sensitivity or specificity. Sensitivity and specificity are important factors in determining the usefulness of EF tests. Sensitivity refers to the probability of identifying abnormal functioning in an impaired individual or “hit rate” of a test, whereas specificity reflects the probability of correctly identifying healthy individual with the test (Cartoni & Lincoln, 2005; Kiel & Kaszniak, 2002). Rubrics are useful scoring tools that divide tasks into component elements and provide a description of levels of performance for each element (Goodrich, 2005; Hanna & Smith, 1998). Rubrics have been widely used to assess student performance (Andrade, 2000; Falchikov, 1986; Goodrich, 1997), but have not been used to score EF tests. The aim of this study was to examine sensitivity and specificity for a clinical test of EF, the Rapid Assessment of Problem Solving test (RAPS) when scored with a rubric that allowed the examiner to describe the quality of performance using a standard that was developed from a large body of normative research. This differs from using the three traditional test scores from the RAPS that require time intensive calculations

Antitrust leniency with multiproduct colluders

We use a global games approach to model alternative implementations of an antitrust leniency program as applied to multiproduct colluders. We derive several policy design lessons; e.g., we show that it is possible that linking leniency across products increases the likelihood of conviction in the first product investigated but reduces it in subsequent products. Thus, firms may have an incentive to form sacrificial cartels and apply for leniency in less valuable products to reduce convictions in more valuable products. Cartel profiling can mitigate this undesirable effect, but also reduces the probability of conviction in the first product investigated

Motivational Factors And The Hospitality Industry: A Case Study Examining The Effects Of Changes In The Working Environment

The Mandarin Oriental Hotel in Bangkok is a world-wide leader in hospitality management. A critical ingredient for their success has been developing and maintaining superior performance from their employees. How is that accomplished? What Human Resource Management (HRM) practices should organizations invest in to acquire and retain great employees? Recent studies have demonstrated the importance of providing a supportive work environment, one that engenders employee satisfaction and promotes effective service performance among hospitality employees. But what is a supportive environment for hotel workers who are required to be responsive to the needs of guests twenty four hours a day? The Mandarin Oriental’s unique approach involved building a separate area in the hotel dedicated to the well-being of their employees. This area—The O-Zone—originated from the idea of providing workplaces which support fun and enjoyment as part of work-life balance. The case focuses attention on how changes in the working environment can significantly enhance the recognition and appreciation of employees A dedicated employee center in the hospitality industry has not been explored before and offers up an exceptional opportunity to examine the effect on motivation and how the center may be appreciated differently by employees based on gender, department and work experience—an important consideration for Human Resources when designing incentive programs

Toward systematic control of cybersickness

Visually induced motion sickness, or cybersickness, has been well documented in all kinds of vehicular simulators and in many virtual environments. It probably occurs in all virtual environments. Cybersickness has many known determinants, including (a short list) field-of-view, flicker, transport delays, duration of exposure, gender, and susceptibility to motion sickness. Since many of these determinants can be controlled, a major objective in designing virtual environments is to hold cybersickness below a specified level a specified proportion of the time. More than 20 years ago C. W. Simon presented a research strategy based on fractional factorial experiments that was capable in principle of realizing this objective. With one notable exception, however, this strategy was not adopted by the human factors community. The main reason was that implementing Simon\u27s strategy was a major undertaking, very time-consuming, and very costly. In addition, many investigators were not satisfied that Simon had adequately addressed issues of statistical reliability. The present paper proposes a modified Simonian approach to the sate objective (holding cybersickness below specified standards) with some loss in the range of application but a greatly reduced commitment of resources

Point-by-point inscription of apodized fiber Bragg gratings

We demonstrate apodized fiber Bragg gratings inscribed with a point-by-point technique. We tailor the grating phase and coupling amplitude through precise control over the longitudinal and transverse position of each laser-inscribed modification. This method of apodization is facilitated by the highly-localized, high-contrast modifications generated by focussed IR femtosecond laser inscription. Our technique provides a simple method for the design and implementation of point-by-point fiber Bragg gratings with complex apodization profiles.Comment: 6 pages, 4 figures, article in revie