Transaction costs can make it unprofitable to rebalance all the way to the ideal portfolio. A single-period analysis using mean-variance theory provides many interesting insights. With fixed or variable costs, there is a non-trading region within which trading does not pay. With only variable costs, any trading is to the boundary of the non-trading region, while fixed costs induce trading to th...

Estimating manufacturing costs of a new product or process soon after research and development (R&D) has commenced can provide a good indication of the project’s economic viability. “Early” estimates can be used to direct research efforts to promising opportunities for cost reduction, and allow businesses to better assign resources to new products. Although potentially compromised because some ...

Flexible conservation management, where measures (e.g., mowing of meadows, removing invasive species) are selected in each decision period depending on the current state of the ecological system, is generally perceived as superior to fixed management, where the same measure is applied in each decision period independent of the current state of the system. In past comparisons of fixed and flexib...

A p-hub center network design problem is definition of some nodes as hubs and allocation of non-hub nodes to them wherein the maximum travel times between any pair of nodes is minimized. The distinctive feature of this study is proposing a new mathematical formulation for modeling costs in a p-hub center problem. Here, instead of considering costs as a linear function of distance, for the first...

BACKGROUND The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) received five years' funding ($21 112 866) from the National Institutes of Health to compare carotid stenting to surgery for stroke prevention in 2500 randomized participants at 40 sites. AIMS Herein we evaluate the change in the CREST budget from a fixed to variable-cost model and recommend strategies for t...

  Background: It has been suggested, although not proven, that presence of concomitant psychiatric disorders may increase the inpatient costs for patients undergoing elective surgery. This study was designed to test the hypothesis that elective lumbar fusion surgery is more costly in patients with under treatment for depression. Methods: This is a retrospective case-control study of 142 patient...

BACKGROUND External cephalic version (ECV) is infrequently performed and 98% of breech presenting fetuses are delivered surgically. Neuraxial analgesia can increase the success rate of ECV significantly, potentially reducing cesarean delivery rates for breech presentation. The current study aims to determine whether the additional cost to the hospital of spinal anesthesia for ECV is offset by c...