•The IIA property is relaxed and random terms are correlated.•Link-based model: no choice sets of paths are required.•Efficient estimation and prediction.•Estimation and cross-validation results ...using real data.
We propose a route choice model that relaxes the independence from irrelevant alternatives property of the logit model by allowing scale parameters to be link specific. Similar to the recursive logit (RL) model proposed by Fosgerau et al. (2013), the choice of path is modeled as a sequence of link choices and the model does not require any sampling of choice sets. Furthermore, the model can be consistently estimated and efficiently used for prediction.
A key challenge lies in the computation of the value functions, i.e. the expected maximum utility from any position in the network to a destination. The value functions are the solution to a system of non-linear equations. We propose an iterative method with dynamic accuracy that allows to efficiently solve these systems.
We report estimation results and a cross-validation study for a real network. The results show that the NRL model yields sensible parameter estimates and the fit is significantly better than the RL model. Moreover, the NRL model outperforms the RL model in terms of prediction.
Choosing Justice Norman Frohlich; Joe A. Oppenheimer
07/2023
eBook
This book presents an entirely new answer to the question: "What is fair?" In their radical approach to ethics, Frohlich and Oppenheimer argue that much of the empirical methodology of the natural ...sciences should be applied to the ethical questions of fairness and justice.
Several studies have investigated surgical residents' perceptions of family planning, and many have investigated medical students' perceptions of surgical specialties; however, there is limited ...research on medical students' perceptions of the impact of family planning on the decision to pursue surgical training. This study aims to investigate male and female medical students’ perceptions of family planning in residency.
A survey was distributed to all medical students at a single medical school in the Midwest between February 2023 and June 2023. The survey was adapted from a prior study investigating resident perceptions of family planning. It included questions about parental leave, having children, and perceived barriers to family planning.
One hundred students completed surveys. Seventy-four (74%) respondents identified as female and 57 (57%) were interested in surgery. Approximately half (55, 55%) of the respondents were strongly or definitely considering having children during residency. However, only eight (8%) students were aware of policies applicable to having children during residency. A majority (85, 85%) felt the decision to pursue surgical residency would prevent or delay having children at their preferred time. Most students felt they would be negatively perceived by peers (62, 62%) and faculty (87, 87%) if they had children during training. The highest perceived barriers to having children during training were work-time demands, childcare barriers, and time away from training.
Both men and women are interested in having children during residency but are unaware of the relevant parental leave policies and are concerned about how training will be impacted by taking time away or a lack of flexibility. Without transparency and flexibility in surgical residency, both men and women may forgo having children during training or choose a specialty they perceive to be more conducive to childbearing.
Technological advances have recently led to the development of urban air mobility (UAM), an alternative transportation mode with several concepts including vehicles operated by on-demand ...fully-automated vertical take-off and landing aircraft (VTOL) for intra-city passenger transportation. However, despite a growing interest in UAM, understanding users’ perceptions to it remains limited. This research aims to identify and quantify the factors affecting the adoption and use of UAM, based on relevant tools from the literature, such as recurring factors in studies on aerial vehicle concepts, ground autonomous vehicles, but also acceptance models, such as the Technology Acceptance Model by Davis et al. (1989). A stated-preference survey was developed to assess the perception of users in terms of adoption time horizon, including options such as the first six years of the service’s implementation, “unsure”, and “never”. The obtained results were evaluated using exploratory factor analyses, and the specification and estimation of suitable discrete choice models, multinomial logit models (MNLs) and ordered logit models (OLMs), with adoption time horizon as dependent variable. Findings revealed the importance of safety and trust, affinity to automation, data concerns, social attitude, and socio-demographics for adoption. Factors, such as the value of time savings, the perception of automation costs, and service reliability, were also found to be highly influential. There was also an indication that skeptical respondents, i.e. answering “unsure”, had a behavior similar to late and non-adopters, i.e. adoption time horizon higher than six years or answering “never”. The summarized results were represented in an extended Technology Acceptance Model for urban air mobility, and provided insights for policymakers and industrial stakeholders.
While contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in ...meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma.BACKGROUND AND PURPOSEWhile contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma.We developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature.MATERIALS AND METHODSWe developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature.The cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively.RESULTSThe cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively.68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.CONCLUSIONS68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.
This fourth edition of the book attests to the Systems Theory Framework's contemporary relevance. It introduces systems theory and the STF, overviews extant career theory, describes the STF's ...applications, and highlights the STF's contributions and future directions.
In this book, career counselling history, best practices as well as contemporary models and methods are brought together. In reflecting on the past, present, and future of career counselling, the ...story of the postmodern, narrative or career construction approach and the model and methods used to advance careers in the 21st century is told. A meta-reflection concept is proposed, based on career construction principles and practices and aimed at providing an examination of repeated reflection in career counselling.
We explicitly derive and explore the optimal consumption and portfolio policies of a loss-averse individual who endogenously updates his or her reference level over time. We find that the individual ...protects current consumption by delaying painful reductions in consumption after a drop in wealth, and increasingly so with higher degrees of endogeneity. The incentive to protect current consumption is stronger with a medium wealth level than with a high or low wealth level. Furthermore, this individual adopts a conservative investment strategy in normal states and typically a more aggressive strategy in good and bad states. Endogeneity of the reference level increases overall risk-taking and generates an incentive to reduce risk exposure with age even without human capital. The welfare loss that this individual would suffer under the conventional constant relative risk aversion (CRRA) consumption and portfolio policies easily exceeds 10%.
This paper was accepted by Tyler Shumway, finance.
PDF
