Specialty care single and multi-period location–allocation models within the Veterans Health Administration

Optimal location of specialty care services within any healthcare network is increasingly important for balancing costs, access to care, and patient-centeredness. Typical long-range planning efforts attempt to address a myriad of quantitative and qualitative issues, including within-network access within reasonable travel distances, space capacity constraints, costs, politics, and community commitments. To help inform these decisions, single and multi-period mathematical integer programs were developed that minimize total procedure, travel, non-coverage, and start-up costs to increase network capacity subject to access constraints. These models have been used to help the Veterans Health Administration (VHA) explore relationships and tradeoffs between costs, coverage, service location, and capacity and to inform larger strategic planning discussions. Results indicate significant opportunity to simultaneously reduce total cost, reduce total travel distances, and increase within-network access, the latter being linked to better care continuity and outcomes. An application to planning short and long-term sleep apnea care across the VHA New England integrated network, for example, produced 10–15% improvements in each performance measure. As an example of further insight provided by these analyses, most optimal solutions increase the amount of outside-network care, contrary to current trends and policies to reduce external referrals.     

Multivariate saddlepoint tests on the mean direction of the von Mises–Fisher distribution

This article provides P values for two new tests on the mean direction of the von Mises–Fisher distribution. The test statistics are obtained from the exponent of the saddlepoint approximation to the density of M-estimators, as suggested by Robinson et al. (Ann Stat 31:1154–1169, 2003). These test statistics are chi-square distributed with asymptotically small relative errors. Despite the high dimensionality of the problem, the proposed P values are accurate and simple to compute. The numerical precision of the P values of the new tests is illustrated by some simulation studies.     

On the computation of optimal monotone mean–variance portfolios via truncated quadratic utility

We report a surprising link between optimal portfolios generated by a special type of variational preferences called divergence preferences (see Maccheroni et al., 2006) and optimal portfolios generated by classical expected utility. As a special case, we connect optimization of truncated quadratic utility (see ?erný, 2003) to the optimal monotone mean–variance portfolios (see Maccheroni et al., 2009), thus simplifying the computation of the latter.     

Time-consistent investment policies in Markovian markets: A case of mean–variance analysis

The optimal investment policy for a standard multi-period mean–variance model is not time-consistent because the variance operator is not separable in the sense of the dynamic programming principle. With a nested conditional expectation mapping, we develop an investment model with time consistency in Markovian markets. Furthermore, we examine the differences of the investment policies with a riskless asset from those without a riskless asset. Analytical solutions for time-consistent optimal investment policies and the resulting mean–variance efficient frontier are obtained. Finally, using numerical examples, we show that the optimal investment policy derived from our model is more efficient than that of the standard mean–variance model in which the trade-off is determined between the mean and variance of the terminal wealth.     

On stochastic comparisons of minimum order statistics from the location–scale family of distributions

We consider stochastic comparisons of minimum order statistics from the location–scale family of distributions that contain most of the popular lifetime distributions. Under certain assumptions, we show that the minimum order statistic of one set of random variables dominates that of another set of random variables with respect to different stochastic orders. Furthermore, we illustrate our results using some well-known specific distributions.     

Spanning tests in return and stochastic discount factor mean–variance frontiers: A unifying approach

We propose new spanning tests that assess if the initial and additional assets share the economically meaningful cost and mean representing portfolios. We prove their asymptotic equivalence to existing tests under local alternatives. We also show that unlike two-step or iterated procedures, single-step methods such as continuously updated GMM yield numerically identical overidentifying restrictions test, so there is arguably a single spanning test. To prove these results, we extend optimal GMM inference to deal with singularities in the long run second moment matrix of the influence functions. Finally, we test for spanning using size and book-to-market sorted US stock portfolios.     

Equilibrium mean–variance reinsurance and investment strategies for a general insurance company under smooth ambiguity

This work investigates the equilibrium investment and reinsurance strategies for a general insurance company under smooth ambiguity. The general insurance company holds shares of an insurance company and a reinsurance company. The claims of the insurer follow a compound Poisson process. The insurer can divide part of the insurance risk to the reinsurer. Besides, the insurer and reinsurer both participate in the financial market and invest in cash and stock. However, the general insurance company is ambiguous about the insurance and financial risks and is an ambiguity-averse manager (AAM). The uncertainties over the insurance and financial risks are described by second-order distributions. The AAM aims to maximize the average performance of the weighted sum surplus process of the insurer and reinsurer under the mean–variance criterion and smooth ambiguity. We present the extended Hamilton–Jacobi–Bellman (HJB) system for the optimization problem combining the mean–variance criterion and smooth ambiguity. In the case that the second-order distributions are Gaussian, we obtain the closed-forms of the equilibrium reinsurance and investment strategies. At the end of this work, sensitivity analyses are presented to show the economic behaviors of the AAM.     

Two new mean–variance enhanced index tracking models based on uncertainty theory

The enhanced index tracking (EIT) problem is concerned with selecting a tracking portfolio that achieves an excess return over a given benchmark with a minimum tracking error. This paper explores the EIT problem by providing two new mean–variance EIT models based on uncertainty theory where stock returns are treated as uncertain variables instead of random variables and stock return distributions are estimated by experts instead of from historical data. First, this paper formulates an uncertain enhanced index tracking (UEIT) model and analyzes the characteristic of the UEIT frontier. Then to reduce the tracking portfolio’s risk, this paper adds a risk index (RI) constraint to the UEIT model and proposes a UEIT-RI model. Next, by comparing the UEIT and UEIT-RI models this paper gives the advantages of the two models. Investors can choose the model according to their preferences. Finally, this paper conducts numerical examples to illustrate the application of the two models and the analysis results.     

Possibilistic mean–variance portfolios versus probabilistic ones: the winner is...

Decisions in Economics and Finance - In this paper, we compare the mean–variance portfolio modeling based on the possibilistic representation of the future stock returns to the one based on...     

A simple mean–dispersion model of ambiguity attitudes

Several characterizations of ambiguity aversion decompose preferences into the expected utility of an act and an adjustment factor, an ambiguity index, or a dispersion function. In each of these cases, the adjustment factor has very little structure imposed on it, and thus these models provide little guidance as to which function to use from the infinite class of possible alternatives. In this paper, we provide a simple axiomatic characterization of mean–dispersion preferences which uniquely determines a subjective probability distribution over a set of possible priors and which uniquely identifies the dispersion function. We provide an algorithm for determining this subjective probability distribution and the coefficient in the dispersion function from experimental data. We also demonstrate that the model accommodates ambiguity aversion in the Ellsberg paradox.     

The bargaining power of teachers’ unions and the allocation of school resources

This paper examines how district size affects the bargaining power of teachers’ unions and the allocation of school resources. Our identification strategy exploits the fact that 33 states mandate collective bargaining while 5 states prohibited it. In states that mandate collective bargaining, we find that beginning salaries and the premium paid to experienced teachers increase with district size while the teacher–pupil ratio declines with district size. In contrast, in states that prohibit collective bargaining we find a negative relationship between district size and the premium paid to experienced teachers. District size also has a stronger positive effect on beginning salaries and a weaker negative effect on teacher–pupil ratios in states that prohibit collective bargaining. Collectively, our results suggest that more powerful unions bargain for more generous returns to teacher seniority at the expense of staffing ratios and base salaries.     

An evaluation of the validity of the Crowne–Marlowe need for approval scale

Over the past four decades, research has consistently documented negative correlations between the Crowne?CMarlowe (CM) social desirability trait scale and numerous measures of sensitive behaviors, conditions, and opinions. These findings have been interpreted as evidence that persons with self-presentation concerns tend to under-report negative information. In contrast to this classic social desirability interpretation, a second perspective, labeled the true-behavior hypothesis, maintains that these correlations in fact reflect accurate reporting of both sets of variables, suggesting that the CM scale is not a sensitive indicator of the social desirability trait. We test these alternative interpretations by examining data from a community survey that collected both self-reports of cocaine use and the biological specimens necessary to validate the self-reports. In bivariate analyses, the CM scale was found to be associated with the concordance of cocaine use reporting and biological assays in a manner consistent with the classic social desirability hypothesis. The CM scale was not found to be associated with actual cocaine use, as measured by drug test assays, a finding inconsistent with the true-behavior hypothesis. After adjusting for other known correlates of substance use in logistic regression models, the CM scale was not associated with cocaine use under-reporting, nor with actual cocaine use behavior. Until further evidence is available, we conclude that the CM may be a questionable indicator of socially desirable reporting behavior in social surveys.     

Peripheral location equals localized labour? Multinationals and the internationalization of training and development in Ireland

The paper examines the impact of MNC internationalization on the training and development of employees, drawing on the findings of a survey of training and work organization among high-tech MNCs operating in Ireland. The survey illustrates clearly that the internationalization of training and development spans a wide occupational spectrum and that it is not solely a feature of a distinct international management cadre. While the literature identifies international managers as the main groups benefiting from international training and development, the findings question the extent to which non-managerial labour can be viewed as primarily local and national in outlook and skill formation. Further, the level of both short-term and longer-term training mobility reflect a wider set of business attributes of multinationals in Ireland.     

Risk allocation in service triads – The case of Dutch and Finnish home care procurement

We compare how Finland and the Netherlands organize home care services, both in legislation and in procurement practices, from a service triad risk perspective. We find Finnish public bodies rely to a great extent on inhouse provision and hybrid outsourcing. Dutch public bodies rely completely on outsourcing, using framework agreements with many care providers in parallel. Incentives used in contracts affect financial and service quality risks assumed by buyers, suppliers, and end-customers in the triad. This research improves our understanding of risk allocation among the actors in the service triad based on buyer decisions on outsourcing and supply market conditions. The risk profiles for all three actors in the home care service triad are affected by the manner in which public bodies outsource home care services: the purchasing practices. The delivery method (whether public and private or all private) and the number of providers impact the information position of the municipality versus the care provider in the triad.     

Existence and computation of the Aumann–Serrano index of riskiness and its extension

Aumann and Serrano (2008) introduce the index of riskiness to quantify the risk of a gamble. We discuss for which gambles this index of riskiness exists by considering the acceptance behavior of CARA-agents. Since for several relevant distributions riskiness is not defined, we suggest an extension of riskiness to all gambles. We prove that this extension is unique and that it satisfies the central duality axiom. Finally, we derive closed-form solutions of extended riskiness and list some applications.     

Analysis of organizational commitment and work–family conflict in view of doctors and nurses

The present study investigates the relationship between organizational commitment and work–family conflict for medical doctors and nurses. Using canonical analysis on questionnaire, this relation has been tested distinctively through three sub-dimensions of organizational commitment listed: affective commitment, continuance commitment and normative commitment. Data collected from 766 (411 doctors and 355 nurses) individuals employed at seven state hospitals and three medical faculties of universities in Ankara. Analysis revealed that the relationship between organizational commitment scale and work–family conflict scale is weak and positive. Results suggest that the more committed the doctors and nurses are to the hospital they work for, the more work–family conflict they experience. On the basis of the sample information obtained in this study, it is possible to claim that if the employees are supported to establish a fair balance between their work and family lives in the guidance of these principles, a strong commitment to the organization will develop.     

Firms’ innovation performance and the role of the metropolitan location. Evidence from the European periphery

ABSTRACT

This paper assesses the role of metropolitan location in explaining firms’ innovation performance while accounting for other internal and external determinants of innovation. Using micro-level dataset and controlling for firm-specific, sector-specific and region-specific features, we identify a nuanced effect of location within metropolitan areas on the innovative performance of companies The results prove to vary for the different measures of innovation output of firms and in particular there is no metropolitan advantage detected for binary self-declared measures of innovations. The advantage is detected for the count-based quantity of innovation measures which is shown to critically depend on the higher performance of metropolitan-based firms in patenting and licencing. The interlinkages between location and firm-size matter and the results are asymmetric with particular benefits arising for micro-firms in their patenting and licencing.     

Learning and stability of the Bayesian–Walrasian equilibrium

Under the Bayesian–Walrasian Equilibrium (BWE) (see Balder and Yannelis, 2009), agents form price estimates based on their own private information, and in terms of those prices they can formulate estimated budget sets. Then, based on his/her own private information, each agent maximizes interim expected utility subject to his/her own estimated budget set. From the imprecision due to the price estimation it follows that the resulting equilibrium allocation may not clear the markets for every state of nature, i.e., exact feasibility of allocations may not occur. This paper shows that if the economy is repeated from period to period and agents refine their private information by observing the past BWE, then in the limit all agents will obtain the same information and market clearing will be reached. The converse is also true. The analysis provides a new way of looking at the asymmetric equilibrium which has a statistical foundation.