scholarly journals AN ANALYSIS OF STRATEGIC BEHAVIOR IN eBAY AUCTIONS

2009 ◽  
Vol 54 (03) ◽  
pp. 441-472 ◽  
Author(s):  
RAUL GONZALEZ ◽  
KEVIN HASKER ◽  
ROBIN C. SICKLES
Keyword(s):  
Repeated Measures ◽  
Strategic Behavior ◽  
Panel Data Analysis ◽  
Consumer Surplus ◽  
Auction Mechanisms ◽  
Jump Bidding ◽  
Private Value Auctions ◽  
Computer Monitors ◽  
Reputation Effects ◽  
Recovery Protocols

A relatively new type of panel data analysis is becoming more and more topical in the applied econometrics literature as auction mechanisms are being explored in more depth. The typical data utilized in such studies involves repeated measures of auction outcomes, where the variable of interest involves order statistics from the sample of bids from many bids on completed auctions for a particular commodity. This article presents structural estimates of bidding behavior in eBay computer monitor auctions. We exploit characteristics of such repeated measures to analyze the efficiency of private value auctions for a relatively homogeneous good, computer monitors sold on eBay. We discuss how outcomes of the auction mechanism can be analyzed and their equilibrium outcomes assessed and evaluate the consumer surplus that is generated from such auctions. Particular attention is given to the collection of the eBay data from data recovery protocols that monitor in real time and in relative detail, characteristics of a particular auction with heterogeneity controls for different types of monitors and for different reputation effects of the auctioneer. Among other findings, our results point to a rejection of the use of Jump Bidding (Avery, 1998) or "Snipe or War" bidding (Roth and Ockenfels, 2002). We also find that longer auctions only have a small effect on price and experienced auctioneers respond to this incentive.

scholarly journals The Effect of Pedal Pump Lymphatic Technique Versus Passive Recovery Following Maximal Exercise: A Randomized Cross-Over Trial

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Joanne DiFrancisco-Donoghue ◽  
Thomas Chan ◽  
Alexandra S. Jensen ◽  
James E. B. Docherty ◽  
Rebecca Grohman ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Maximal Exercise ◽  
Lactate Concentration ◽  
The Body ◽  
Intense Exercise ◽  
Passive Recovery ◽  
Significant Difference ◽  
Recovery Protocols

Abstract Context Muscle damage and delayed onset muscle soreness (DOMS) can occur following intense exercise. Various modalities have been studied to improve blood lactate accumulation, which is a primary reason for DOMS. It has been well established that active recovery facilitates blood lactate removal more rapidly that passive recovery due to the pumping action of the muscle. The pedal pump is a manual lymphatic technique used in osteopathic manipulative medicine to increase lymphatic drainage throughout the body. Pedal pump has been shown to increase lymphatic flow and improve immunity. This may improve circulation and improve clearance of metabolites post-exercise. Objective This study compared the use of pedal pump lymphatic technique to passive supine recovery following maximal exercise. Methods 17 subjects (male n = 10, age 23 ± 3.01; female n = 7, age 24 ± 1.8), performed a maximal volume O2 test (VO2 max) using a Bruce protocol, followed by a recovery protocol using either pedal pump technique or supine passive rest for 10 min, followed by sitting for 10 min. Outcome measures included blood lactate concentration (BL), heart rate (HR), systolic blood pressure (SBP) and VO2. Subjects returned on another day to repeat the VO2 max test to perform the other recovery protocol. All outcomes were measured at rest, within 1- minute post-peak exercise, and at minutes 4, 7, 10 and 20 of the recovery protocols. A 2 × 6 repeated measures ANOVA was used to compare outcome measures (p ≤ 0.05). Results No significant differences were found in VO2, HR, or SBP between any of the recovery protocols. There was no significant difference in BL concentrations for recovery at minutes 4, 7, or 10 (p > 0.05). However, the pedal pump recovery displayed significantly lower BL concentrations at minute 20 of recovery (p = 0.04). Conclusion The pedal pump significantly decreased blood lactate concentrations following intense exercise at recovery minute 20. The use of manual lymphatic techniques in exercise recovery should be investigated further.

Timing of Emissions and Effects of Emission Taxes in Durable-Goods Oligopolies

2018 ◽  
Vol 18 (4) ◽  
Author(s):  
Amagoia Sagasta ◽  
José M. Usategui
Keyword(s):  
Imperfect Competition ◽  
Durable Goods ◽  
Strategic Behavior ◽  
Consumer Surplus ◽  
Perfect Competition ◽  
Emission Tax ◽  
Durable Good ◽  
Emission Taxes ◽  
The Future ◽  
Future Emission

Abstract Given an oligopoly of firms that produce and sell a durable good that causes pollution at production, during use or at disposal, the effects of present and future emission taxes on quantities, emissions, consumer surplus, producer surplus and the sum of consumer and producer surpluses and the revenue from emission taxes for each type of emission are analyzed. Among other results, it is proved that producers may support an increase in the emission tax in the future or in the present, that emissions in the present may be increasing in the emission tax in the future and that the timing of emissions may affect the directions of some effects of a change in an emission tax on welfare variables. The results obtained are based on the interaction between present and future emission taxes, the intertemporal effects of such taxes, imperfect competition, the strategic behavior of each firm in stealing sales from its rivals in the present and in the future, the type of emission and the producers’ commitment problem. The analysis is extended to the cases of monopoly and perfect competition.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

Vestibular Function and Motion Sickness Susceptibility: Videonystagmographic Evidence From Oculomotor and Caloric Tests

2020 ◽  
Vol 29 (2) ◽  
pp. 188-198
Author(s):  
Cynthia G. Fowler ◽  
Margaret Dallapiazza ◽  
Kathleen Talbot Hadsell
Keyword(s):  
Phase Velocity ◽  
Motion Sickness ◽  
Repeated Measures ◽  
Short Form ◽  
Vestibular Function ◽  
Slow Phase ◽  
Test Results ◽  
Normal Range ◽  
Slow Phase Velocity ◽  
Caloric Tests

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.

Effects of Aging on the Subcortical Encoding of Stop Consonants

2020 ◽  
Vol 29 (3) ◽  
pp. 391-403
Author(s):  
Dania Rishiq ◽  
Ashley Harkrider ◽  
Cary Springer ◽  
Mark Hedrick
Keyword(s):  
Older Adults ◽  
Repeated Measures ◽  
Mixed Model ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Aging Effects ◽  
Formant Frequency ◽  
Place Of Articulation ◽  
Second Formant ◽  
Effects Of Aging

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.

Evaluation of Acoustic Analyses of Voice in Nonoptimized Conditions

2020 ◽  
Vol 63 (12) ◽  
pp. 3991-3999
Author(s):  
Benjamin van der Woerd ◽  
Min Wu ◽  
Vijay Parsa ◽  
Philip C. Doyle ◽  
Kevin Fung
Keyword(s):  
Repeated Measures ◽  
Voice Quality ◽  
Data Sets ◽  
Acoustic Measurements ◽  
Sample Collection ◽  
Experimental Conditions ◽  
Environment Analysis ◽  
Acoustic Measures ◽  
Recording Conditions ◽  
Cepstral Peak Prominence

Objectives This study aimed to evaluate the fidelity and accuracy of a smartphone microphone and recording environment on acoustic measurements of voice. Method A prospective cohort proof-of-concept study. Two sets of prerecorded samples (a) sustained vowels (/a/) and (b) Rainbow Passage sentence were played for recording via the internal iPhone microphone and the Blue Yeti USB microphone in two recording environments: a sound-treated booth and quiet office setting. Recordings were presented using a calibrated mannequin speaker with a fixed signal intensity (69 dBA), at a fixed distance (15 in.). Each set of recordings (iPhone—audio booth, Blue Yeti—audio booth, iPhone—office, and Blue Yeti—office), was time-windowed to ensure the same signal was evaluated for each condition. Acoustic measures of voice including fundamental frequency ( f o ), jitter, shimmer, harmonic-to-noise ratio (HNR), and cepstral peak prominence (CPP), were generated using a widely used analysis program (Praat Version 6.0.50). The data gathered were compared using a repeated measures analysis of variance. Two separate data sets were used. The set of vowel samples included both pathologic ( n = 10) and normal ( n = 10), male ( n = 5) and female ( n = 15) speakers. The set of sentence stimuli ranged in perceived voice quality from normal to severely disordered with an equal number of male ( n = 12) and female ( n = 12) speakers evaluated. Results The vowel analyses indicated that the jitter, shimmer, HNR, and CPP were significantly different based on microphone choice and shimmer, HNR, and CPP were significantly different based on the recording environment. Analysis of sentences revealed a statistically significant impact of recording environment and microphone type on HNR and CPP. While statistically significant, the differences across the experimental conditions for a subset of the acoustic measures (viz., jitter and CPP) have shown differences that fell within their respective normative ranges. Conclusions Both microphone and recording setting resulted in significant differences across several acoustic measurements. However, a subset of the acoustic measures that were statistically significant across the recording conditions showed small overall differences that are unlikely to have clinical significance in interpretation. For these acoustic measures, the present data suggest that, although a sound-treated setting is ideal for voice sample collection, a smartphone microphone can capture acceptable recordings for acoustic signal analysis.

The Effect of Real-Time Feedback Using a Smartwatch on the Clinical Behavior of Novice Student Clinicians

2017 ◽  
Vol 2 (11) ◽  
pp. 79-90
Author(s):  
Courtney G. Scott ◽  
Trina M. Becker ◽  
Kenneth O. Simpson
Keyword(s):  
Real Time ◽  
Rating Scales ◽  
Qualitative Interviews ◽  
Communication Disorders ◽  
Preliminary Evidence ◽  
Single Subject ◽  
Clinical Behavior ◽  
Stimulus Response ◽  
Treatment Data ◽  
Computer Monitors

The use of computer monitors to provide technology-based written feedback during clinical sessions, referred to as “bug-in-the-eye” (BITi) feedback, recently emerged in the literature with preliminary evidence to support its effectiveness (Carmel, Villatte, Rosenthal, Chalker & Comtois, 2015; Weck et al., 2016). This investigation employed a single-subject, sequential A-B design with two participants to observe the effects of implementing BITi feedback using a smartwatch on the clinical behavior of student clinicians (SCs). Baseline and treatment data on the stimulus-response-consequence (S-R-C) contingency completion rates of SCs were collected using 10 minute segments of recorded therapy sessions. All participants were students enrolled in a clinical practicum experience in a communication disorders and sciences (CDS) program. A celeration line, descriptive statistics, and stability band were used to analyze the data by slope, trend, and variability. Results demonstrated a significant correlative relationship between BITi feedback with a smartwatch and an increase in positive clinical behaviors. Based on qualitative interviews and exit rating scales, SCs reported BITi feedback was noninvasive and minimally distracting. Preliminary evidence suggests BITi feedback with a smartwatch may be an effective tool for providing real-time clinical feedback.

Inducing Unconscious Stress

2020 ◽  
Vol 34 (3) ◽  
pp. 192-201
Author(s):  
Melanie M. van der Ploeg ◽  
Jos F. Brosschot ◽  
Markus Quirin ◽  
Richard D. Lane ◽  
Bart Verkuil
Keyword(s):  
Repeated Measures ◽  
Activity Patterns ◽  
Physiological Changes ◽  
Implicit Measures ◽  
Prime Word ◽  
Student Sample ◽  
Priming Task ◽  
Subject Design ◽  
The Relationship ◽  
Stress And Health

Abstract. Stress-related stimuli may be presented outside of awareness and may ultimately influence health by causing repetitive increases in physiological parameters, such as blood pressure (BP). In this study, we aimed to corroborate previous studies that demonstrated BP effects of subliminally presented stress-related stimuli. This would add evidence to the hypothesis that unconscious manifestations of stress can affect somatic health. Additionally, we suggest that these findings may be extended by measuring affective changes relating to these physiological changes, using measures for self-reported and implicit positive and negative affectivity. Using a repeated measures between-subject design, we presented either the prime word “angry” ( n = 26) or “relax” ( n = 28) subliminally (17 ms) for 100 trials to a student sample and measured systolic and diastolic BP, heart rate (HR), and affect. The “angry” prime, compared to the “relax” prime, did not affect any of the outcome variables. During the priming task, a higher level of implicit negative affect (INA) was associated with a lower systolic BP and diastolic BP. No association was found with HR. Self-reported affect and implicit positive affect were not related to the cardiovascular (CV) activity. In sum, anger and relax primes elicited similar CV activity patterns, but implicit measures of affect may provide a new method to examine the relationship between (unconscious) stress and health.

I Like Myself, I Really Do (at Least Right Now)

2020 ◽  
Vol 36 (1) ◽  
pp. 196-206 ◽  
Author(s):  
Almut Rudolph ◽  
Michela Schröder-Abé ◽  
Astrid Schütz
Keyword(s):  
Construct Validity ◽  
Performance Feedback ◽  
Repeated Measures ◽  
Temporal Stability ◽  
Social Feedback ◽  
Student Sample ◽  
Empirically Supported ◽  
Good Internal Consistency ◽  
And Performance ◽  
Induced Changes

Abstract. In five studies, we evaluated the psychometric properties of a revised German version of the State Self-Esteem Scale (SSES; Heatherton & Polivy, 1991 ). In Study 1, the results of a confirmatory factor analysis on the original scale revealed poor model fit and poor construct validity in a student sample that resembled those in the literature; thus, a revised 15-item version was developed (i.e., the SSES-R) and thoroughly validated. Study 2 showed a valid three-factor structure (Performance, Social, and Appearance) and good internal consistency of the SSES-R. Correlations between subscales of trait and state SE empirically supported the scale’s construct validity. Temporal stability and intrapersonal sensitivity of the scale to naturally occurring events were investigated in Study 3. Intrapersonal sensitivity of the scale to experimentally induced changes in state SE was uncovered in Study 4 via social feedback (acceptance vs. rejection) and performance feedback (positive vs. negative). In Study 5, the scale’s interpersonal sensitivity was confirmed by comparing depressed and healthy individuals. Finally, the usefulness of the SSES-R was demonstrated by assessing SE instability as calculated from repeated measures of state SE.

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