Subjective Uncertainty over Behavior Strategies: A Correction

In order to model the subjective uncertainty of a player over the behavior strategies of an opponent, one must consider the player's beliefs about the opponent's play at information sets that the player thinks have probability zero. This corregendum uses “trembles” to provide a definition of the convex hull of a set of behavior strategies. This corrects a definition we gave in [E. Dekel, D. Fudenberg, and D. K. Levine, 1999, J. Econ. Theory89, 165-185], which led to two of the solution concepts we defined there not having the properties we intended. Journal of Economic Literature Classification Numbers: C72, D82, C610.     

The relations among child quality,family structure,and the value of the mother's time in Malaysia

A model of the determinants of child quality and of the value of a woman's time is developed and tested using data from the Malaysian Family Life Survey of 1976-1977. Child quality is measured by educational attainment; factors influencing the value of the mother's time include size and age composition of household, family income, education, and hours worked. The results indicate that size and age composition of household affect a woman's asking wage. However, more data are needed before the effects of family structure on schooling can be measured with confidence.     

A cost analysis of SIR-Spheres yttrium-90 resin microspheres versus tyrosine kinase inhibitors in the treatment of unresectable hepatocellular carcinoma in France,Italy, Spain and the UK

Abstract

Background and aims: A wide range of treatment options are available for hepatocellular carcinoma (HCC), including systemic treatment with tyrosine kinase inhibitors (TKIs) such as sorafenib and lenvatinib, immunotherapies, locoregional therapies such as selective internal radiation therapy (SIRT) and treatments with curative intent such as resection, radiofrequency ablation and liver transplantation. Given the substantial economic burden associated with HCC treatment, the aim of the present analysis was to establish the cost of using SIRT with SIR-Spheres yttrium-90 (Y-90) resin microspheres versus TKIs from healthcare payer perspectives in France, Italy, Spain and the United Kingdom (UK).

Methods: A cost model was developed to capture the costs of initial systemic treatment with sorafenib (95%) or lenvatinib (5%) versus SIRT in patients with HCC in Barcelona Clinic Liver Cancer (BCLC) stages B and C. A nested Markov model was utilized to model transitions between progression-free survival (PFS), progression and death, in addition to transitions between subsequent treatment lines. Cost and resource use data were identified from published sources in each of the four countries.

Results: Relative to TKIs, SIRT with SIR-Spheres Y-90 resin microspheres were found to be cost saving in all four country settings, with the additional costs of the microspheres and the SIRT procedure being more than offset by reductions in drug and drug administration costs, and treatment of adverse events. Across the four country settings, total cost savings with SIR-Spheres Y-90 resin microspheres fell within the range 5.4–24.9% and SIRT resulted in more patients ultimately receiving treatments with curative intent (4.6 vs. 1.4% of eligible patients).

Conclusion: SIR-Spheres Y-90 resin microspheres resulted in cost savings relative to TKIs in the treatment of unresectable HCC in all four country settings, while increasing the proportion of patients who become eligible for treatments with curative intent.     

A new approach to optimal selection of services in health care organizations.

A new reimbursement policy adopted by Medicare in 1983 caused financial difficulties for many hospitals and health care organizations. Several organizations responded to these difficulties by developing systems to carefully measure their costs of providing services. The purpose of such systems was to provide relevant information about the profitability of hospital services. This paper presents a new method of making hospital service selection decisions: it is based on an optimization model that avoids arbitrary cost allocations as a basis for computing the costs of offering a given service. The new method provides more reliable information about which services are profitable or unprofitable, and it provides an accurate measure of the degree to which a service is profitable or unprofitable. The new method also provides useful information about the sensitivity of the optimal decision to changes in costs and revenues. Specialized algorithms for the optimization model lead to very efficient implementation of the method, even for the largest health care organizations.     

The effect of rule 12b-1 on bond fund expense ratios

This paper presents empirical evidence that bond mutual funds which have adopted the use of 12b-1 fees have not achieved the goal of lowering expense ratios. Using a model specific to bond funds, as opposed to generic models used in previous studies on equity funds, the analysis confirms that the 12b-1 fee is an additional cost borne by shareholders of the fund without any additional benefit. However, this cost as a percent of the net asset value of the fund has decreased from 1991 through 1994. This reduction coincides with the submission of a proposed rule change by the National Association of Security Dealers concerning maximum sales charges imposed by mutual funds on December 28, 1990 and the implementation of limits on 12b-1 fees which became effective in July of 1993.     

Restructuring materiel management functions: a method for prioritizing changes and reducing costs

The success of any manager depends highly on the ability to seize on opportunities that will achieve the organization's goals. Hospitals are currently searching for ways to reduce costs while maintaining or enhancing the quality of services. Quality services are increasingly being defined as those that are most responsive to customer needs. It is important, as hospital management restructures materiel systems or methods of operation for reduced costs, to focus on the user departments as the customers. The consolidation of materiel management activity should not be seen as a loss of control at the user department level. Instead it can be seen as a new way of providing service with higher quality. User departments should see concrete benefits on a weekly basis, including reduced time spent on materiel management functions; increased planning of purchasing, inventory, and distribution functions; and assistance in meeting restricted supply budgets.     

Children's hospitals: specialty hospitals that treat children specially

Any reader who has children will agree that they make special patients, whether at home or in the hospital. These patients have unique requirements for love and compassionate care, and children's hospitals deliver on their promises. The well-run children's hospitals researched for this article have converted their material management operational challenges to opportunities. They have built thoughtful material management strategic plans, reorganized their support services to provide customer service to end users, and they have centered their materiel management efforts around service and quality improvement.     

On estimating the reliability after sequentially estimating the mean: The exponential case

Sequential estimation problems for the mean parameter of an exponential distribution has received much attention over the years. Purely sequential and accelerated sequential estimators and their asymptotic second-order characteristics have been laid out in the existing literature, both for minimum risk point as well as bounded length confidence interval estimation of the mean parameter. Having obtained a data set from such sequentially designed experiments, the paper investigates estimation problems for the associatedreliability function. Second-order approximations are provided for the bias and mean squared error of the proposed estimator of the reliability function, first under a general setup. An ad hoc bias-corrected version is also introduced. Then, the proposed estimator is investigated further under some specific sequential sampling strategies, already available in the literature. In the end, simulation results are presented for comparing the proposed estimators of the reliability function for moderate sample sizes and various sequential sampling strategies.     

Restricted maximum likelihood estimation under Eisenhart model Ill

For a balanced two-way mixed model, the maximum likelihood (ML) and restricted ML (REML) estimators of the variance components were obtained and compared under the non-negativity requirements of the variance components by L ee and K apadia (1984). In this note, for a mixed (random blocks) incomplete block model, explicit forms for the REML estimators of variance components are obtained. They are always non-negative and have smaller mean squared error (MSE) than the analysis of variance (AOV) estimators. The asymptotic sampling variances of the maximum likelihood (ML) estimators and the REML estimators are compared and the balanced incomplete block design (BIBD) is considered as a special case. The ML estimators are shown to have smaller asymptotic variances than the REML estimators, but a numerical result in the randomized complete block design (RCBD) demonstrated that the performances of the REML and ML estimators are not much different in the MSE sense.