On the Efficiency of All-Pay Mechanisms

We study the inefficiency of mixed equilibria, expressed as the price of anarchy, of all-pay auctions in three different environments: combinatorial, multi-unit and single-item auctions. First, we consider item-bidding combinatorial auctions where m all-pay auctions run in parallel, one for each good. For fractionally subadditive valuations, we strengthen the upper bound from 2 [Syrgkanis and Tardos STOC'13] to 1.82 by proving some structural properties that characterize the mixed Nash equilibria of the game. Next, we design an all-pay mechanism with a randomized allocation rule for the multi- unit auction. We show that, for bidders with submodular valuations, the mechanism admits a unique, 75% efficient, pure Nash equilibrium. The efficiency of this mechanism outperforms all the known bounds on the price of anarchy of mechanisms used for multi-unit auctions. Finally, we analyze single-item all-pay auctions motivated by their connection to contests and show tight bounds on the price of anarchy of social welfare, revenue and maximum bid.Comment: 26 pages, 2 figures, European Symposium on Algorithms(ESA) 201

SF-36 includes less Parkinson Disease (PD)-targeted content but is more responsive to change than two PD-targeted health-related quality of life measures

To compare validity including responsiveness, and internal consistency reliability and scaling assumptions of a generic (SF-36) and Parkinson Disease (PD)-targeted (PDQ-39; PDQUALIF) health-related quality of life (HRQOL) measures. Ninety-six PD patients were administered for all HRQOL measures by telephonic interview at baseline and 18 months. Relative efficiency and responsiveness were compared relative to four external criteria (self-ratings of PD’s daily effects, global Quality of Life, PD symptom severity, and a depression screener). We examined whether PD-targeted measures explained unique variance beyond the SF-36 by regressing criterion variables on HRQOL scales/items. Adequacy of PD-targeted measures’ original scaling was explored by item-scale correlations. Relative efficiency estimates were similar for generic and PD-targeted measures across all criteria. Responsiveness analyses showed that the SF-36 yielded large (>0.8) effect sizes (ES) for three of eight scales for each of two criterion variables, compared to only one large ES for any scale in either PD-targeted measure. Adjusted R 2 increased from 14 to 27% in regression models that included PD-targeted items compared to models with only SF-36 scales. Item-scale correlations showed significant cross-loading of items across scales of the PD-targeted measures. SF-36 responsiveness was better than that of two PD-targeted measures, yet those measures had content that significantly explains PD patients’ HRQOL

The development and validation of the Dementia Quality of Life Scale for Older Family Carers (DQoL-OC)

Purpose: Little is known about how caregiving affects the quality of life (QoL) of older family carers and no dementia and age-specific QoL scale is available for use with this population. This study aimed to develop and validate a unique dementia caregiving- and age-specific tool – the ‘Dementia Quality of Life Scale for Older Family Carers’ (DQoL-OC). Methods: The scale items were identified in focus groups with older family carers in the UK. Content and face validity were evaluated by a panel of six experts. A set of 100 items assessed on a 5-point Likert scale was tested with 182 older family carers. Test–re-test reliability was conducted with 18 individuals. Exploratory factor analysis was used to identify the QoL model and reduce the number of scale items. Convergent construct validity and internal consistency were also established. Results: A one-factor solution containing 22 items was obtained. Test–re-test reliability (lower bound r = 0.835; p < 0.001), internal consistency (Cronbach's α = 0.936), and convergent construct validity were established. Significantly lower levels of QoL were found in female older carers; those who perceived their relatives with dementia as being at the earlier stages of the disease and with unstable dementia symptoms; those providing care more hours per day and more days per week; and those in younger-old age. Conclusions: The DQoL-OC is a valid and reliable scale that will be useful for research and in clinical practice with older family carers of people with dementia. These study results will inform future health and social care aiming to improve life quality for this overlooked population of carers

Development and preliminary evaluation of a quality of life measure targeted at dementia caregivers

<p>Abstract</p> <p>Background</p> <p>Providing care for individuals with a progressive, debilitating condition such as dementia can adversely impact the quality of life (QOL) of informal caregivers. To date, there is no existing caregiver quality of life measure for dementia caregivers with breadth of coverage or that is applicable to caregivers of diverse ethnic backgrounds. The purpose of this study was to develop and evaluate a caregiver-targeted quality-of-life measure (CGQOL) for informal caregivers of persons with dementia that can be used with caregivers from a variety of ethnicities.</p> <p>Methods</p> <p>91 items were field tested by telephone interviews with 179 English-speaking and 21 monolingual Spanish-speaking caregivers of persons with dementia. Repeat interviews were conducted with 71 caregivers. Administration time, scale score distributions, item-scale correlations, reliability, and associations of scales with patient and caregiver demographic and caregiving characteristics were estimated. Structure of associations among scales was examined using exploratory factor analysis.</p> <p>Results</p> <p>Item analysis yielded 80 items distributed across 10 scales, with median administration time of 17 minutes [IQR 13.5–22 minutes] and minimal missing data. There were few floor or ceiling effects in scale score distributions. Internal consistency reliability was ≥ 0.78 for all scales; test-retest reliability (intraclass correlation) estimates exceeded 0.70 for 6 scales. More hours weekly spent in caregiving was uniquely associated with worse quality of life on 8 scales (p's ≤ 0.05). Three higher-order dimensions of caregiving assistance, emotional and social concerns, and spirituality and benefits were identified.</p> <p>Conclusion</p> <p>These preliminary results support subsequent evaluation of test-retest reliability, construct validity, and responsiveness to change of this quality-of-life measure for caregivers from diverse ethnicities.</p

Second-price auctions with private entry costs

We study asymmetric second-price auctions under incomplete information. The bidders have potentially different, commonly-known, valuations for the object and private information about their entry costs. The seller, however, does not benefit from these entry costs. We calculate the equilibrium strategies of the bidders and analyze the optimal design for the seller in this environment

Optimistic irrationality and overbidding in private value auctions

Bidding one’s value in a second-price, private-value auction is a weakly dominant solution (Vickrey in J Finance 16(1):8–37, 1961), but repeated experimental studies find more overbidding than underbidding. We propose a model of optimistically irrational bidders who understand that there are possible gains and losses associated with higher bids but who may overestimate the additional probability of winning and/or underestimate the potential losses when bidding above value. These bidders may fail to discover the dominant strategy—despite the fact that the dominant strategy only requires rationality from bidders—but respond in a common sense way to out-of-equilibrium outcomes. By varying the monetary consequences of losing money in experimental auctions we observe more overbidding when the cost to losing money is low, and less overbidding when the cost is high. Our findings lend themselves to models in which less than fully rational bidders respond systematically to out-of-equilibrium incentives, and we find that our model better fits the effects of our manipulations than most of the existing models we consider

Causes of crises and appropriate interventions: the views of people with dementia, carers and healthcare professionals

The aims of this study were to identify which factors may lead to crisis for people with dementia and their carers and identify interventions these individuals believe could help in crisis. Qualitative study using focus groups to compare the perspectives of people with dementia, family carers and healthcare professionals on causes of crises and crisis interventions. To help in a crisis, people with dementia were favourable towards support from family and friends, access to mobile phones and home adaptations to reduce risks. Carers were keen on assistive technology and home adaptation. Both carers and staff valued carer training and education, care plans and well-coordinated care. Staff were the only group emphasizing more intensive interventions such as emergency home respite and extended hours services. In terms of causes of crises, people with dementia focused on risks and hazards in their home, whereas family carers emphasized carer stress and their own mental health problems. Staff, in contrast were concerned about problems with service organization and coordination leading to crises. Physical problems were less commonly identified as causes of crises but when they did occur they had a major impact. Practical interventions such as home adaptations, assistive technology, education and training for family carers, and flexible home care services were highly valued by service users and their families during times of crisis and may help prevent hospital admissions. Specialist home care was highly valued by all groups