The Demand for Insurance: Expected Utility Theory from a Gain Perspective

Expected utility theory holds that the demand for insurance is a demand for certainty, because under the conventional specification of the theory, it appears as if buyers of insurance prefer certain losses to actuarially equivalent uncertain ones. Empirical studies, however, show that individuals actually prefer uncertain losses to actuarially equivalent certain ones. This paper attempts to reconcile expected utility theory with this empirical evidence by suggesting that insurance is demanded to obtain an income payoff in the Abad@ state. This specification is mathematically equivalent to the conventional specification and consistent with this and other empirical evidence, but it implies that the demand for insurance has nothing to do with demand for certainty

A theory of demand for gambles

Although gambling is primarily an economic activity, no single theory of the demand for gambles has gained wide-spread acceptance among economists. This paper proposes a simple model of the demand for gambling that is based on the standard economic assumptions that (1) resources are scarce and (2) consumers utility increases with income at a decreasing rate. This model has the advantages that (1) it is based solely on changes in income, (2) is potentially applicable to most consumers, (3) preserves the assumption of diminishing marginal utility of income, (4) is consistent with the insurance-buying gambler, and (5) has intuitive appeal

Some Effects of 30 Years of Weir-Management on Coastal Marsh Aquatic Vegetation and Implications to Waterfowl Management

Aquatic vegetation was compared between weir-managed and unmanaged brackish marsh ponds at Marsh Island, Louisiana, parts of which have been weir-managed since 1958. Coverage by aquatic vegetation was greater in weir-managed ponds than in unmanaged ponds, but weir-management affected individual species differently. Eleocharis parvula was more common in unmanaged ponds than in managed ponds during the early 1960s but has not occurred in any ponds sampled since then. Ceratophyllum demersum and the dominant plants Myriophyllum spicatum and Ruppia maritima were more common in weir-managed ponds than in unmanaged ponds, although the magnitude of the difference varied greatly among sample dates. Because Myriophyllum spicatum and Ruppia maritima are important and preferred duck foods in Louisiana brackish marsh, it was concluded that weir-management improved habitat quality for migrant and resident ducks at Marsh Island. Weir-managed ponds contained more aquatic vegetation than unmanaged ponds in 1988, even though the crest of weirs had lost 15 cm of elevation relative to rising sea level and the accreting marsh surface. This suggests that aquatic vegetation can be increased with a greater degree of water exchange than previously believed, which is desired to reduce interference to juvenile fish and crustacean movement. Weir-managed and unmanaged ponds did not differ in pond depth, which suggests that weir-management did not affect sedimentation

Cost effectiveness of telecare management for pain and depression in patients with cancer: results from a randomized trial

OBJECTIVE: Pain and depression are prevalent and treatable symptoms among patients with cancer, yet they are often undetected and undertreated. The Indiana Cancer Pain and Depression (INCPAD) trial demonstrated that telecare management can improve pain and depression outcomes. This article investigates the incremental cost effectiveness of the INCPAD intervention. METHODS: The INCPAD trial was conducted in 16 community-based urban and rural oncology practices in Indiana. Of the 405 participants, 202 were randomized to the intervention group and 203 to the usual-care group. Intervention costs were determined, and effectiveness outcomes were depression-free days and quality-adjusted life years. RESULTS: The intervention group was associated with a yearly increase of 60.3 depression-free days (S.E. = 15.4; P < 0.01) and an increase of between 0.033 and 0.066 quality-adjusted life years compared to the usual care group. Total cost of the intervention per patient was US$1189, which included physician, nurse care manager and automated monitoring set-up and maintenance costs. Incremental cost per depression-free day was US$19.72, which yields a range of US$18,018 to US$36,035 per quality-adjusted life year when converted to that metric. When measured directly, the incremental cost per quality-adjusted life year ranged from US$10,826 based on the modified EQ-5D to US$73,286.92 based on the SF-12. CONCLUSION: Centralized telecare management, coupled with automated symptom monitoring, appears to be a cost effective intervention for managing pain and depression in cancer patients

Arbuscular Mycorrhizae Occur in Common Spartina Species

We report the presence of arbuscular mycorrhizae (AM) in Spartina alterniflora Loisel roots. Roots were sampled for AM in field-collected and greenhouse-maintained Spartina patens (Aiton) Muhl. and S. alterniflora, the dominant species of Louisiana’s brackish and saline marshes, respectively. Previous reports of AM association in these Spartina sp. are limited and conflicting. Field-collected S. alterniflora had minimal AM (2.4%), whereas 39.5% of the S. patens roots examined were AM colonized. Greenhouse conditions of reduced salinity [3 parts per thousand (ppt)] appeared to increase AM association for S. patens compared with field samples. AM occurrence varied significantly among the three sample sites. Our results of low AM association in S. alterniflora differ from previous studies and confirm one previous report of AM in S. patens. Confirming AM association previously thought to be nonexistent in S. alterniflora marshes is a necessary first step in determining if AM influence zonation and competition

Supernova Remnants Associated with Molecular Clouds in the Large Magellanic Cloud

We used the Swedish-ESO Submillimeter Telescope (SEST) to search for CO emission associated with three supernova remnants (SNRs) in the Large Magellanic Cloud: N49, N132D, and N23. Observations were carried out in the J=2-1 rotational transition of CO (230.5 GHz) where the half power beamwidth of the SEST is 23". Molecular clouds were discovered near N49 and N132D; no CO emission was discovered in the region we mapped near N23. The N49 cloud has a peak line temperature of 0.75 K, spatial scale of ~7 pc and virial mass of ~30,000 solar masses. The N132D cloud is brighter with a peak temperature of 5 K; it is also larger ~22 pc and considerably more massive 200,000 solar masses. The velocities derived for the clouds near N49 and N132D, +286.0 km/s and +264.0 km/s, agree well with the previously known velocities of the associated SNRs: +286 km/s and +268 km/s, respectively. ROSAT X-ray images show that the ambient density into which the remnants are expanding appears to be significantly increased in the direction of the clouds. Taken together these observations indicate a physical association between the remnants and their respective, presumably natal, molecular clouds. The association of N49 and N132D with dense regions of molecular material means that both were likely products of short-lived progenitors that exploded as core-collapse supernovae.Comment: 26 pages, including 9 postscript figs, LaTeX (includes aaspp.sty), accepted by Ap.J. for vol 480, May 10, 199

Using Cerebrospinal Fluid Biomarker Testing to Target Treatment to Patients with Mild Cognitive Impairment: A Cost-Effectiveness Analysis

Objective Cerebrospinal fluid (CSF) biomarkers are shown to facilitate a risk identification of patients with mild cognitive impairment (MCI) into different risk levels of progression to Alzheimer’s disease (AD). Knowing a patient’s risk level provides an opportunity for earlier interventions, which could result in potential greater benefits. We assessed the cost effectiveness of the use of CSF biomarkers in MCI patients where the treatment decision was based on patients’ risk level. Methods We developed a state-transition model to project lifetime quality-adjusted life-years (QALYs) and costs for a cohort of 65-year-old MCI patients from a US societal perspective. We compared four test-and-treat strategies where the decision to treat was based on a patient’s risk level (low, intermediate, high) of progressing to AD with two strategies without testing, one where no patients were treated during the MCI phase and in the other all patients were treated. We performed deterministic and probabilistic sensitivity analyses to evaluate parameter uncertainty. Results Testing and treating low-risk MCI patients was the most cost-effective strategy with an incremental cost-effectiveness ratio (ICER) of US$37,700 per QALY. Our results were most sensitive to the level of treatment effectiveness for patients with mild AD and for MCI patients. Moreover, the ICERs for this strategy at the 2.5th and 97.5th percentiles were US$18,900 and US$50,100 per QALY, respectively. Conclusion Based on the best available evidence regarding the treatment effectiveness for MCI, this study suggests the potential value of performing CSF biomarker testing for early targeted treatments among MCI patients with a narrow range for the ICER