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Choice Experiments (choice + experiment)
Kinds of Choice Experiments Selected AbstractsForecasting the Adoption of GM Oilseed Rape: Evidence from a Discrete Choice Experiment in GermanyJOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2008Gunnar Breustedt C42; C81; Q12; Q16 Abstract This paper explores farmers' willingness to adopt genetically modified (GM) oilseed rape prior to its commercial release and estimates the ,demand' for the new technology. The analysis is based upon choice experiments with 202 German arable farmers. A multinomial probit estimation reveals that GM attributes such as gross margin, expected liability from cross pollination, or flexibility in returning to conventional oilseed rape significantly affect the likelihood of adoption. Neighbouring farmers' attitudes towards GM cropping and a number of farmer and farm characteristics were also found to be significant determinants of prospective adoption. Demand simulations suggest that adoption rates are very sensitive to the profit difference between GM and non-GM rape varieties. A monopolistic seed price would substantially reduce demand for the new technology. A monopolistic seed supplier would reap between 45% and 80% of the GM rent, and the deadweight loss of the monopoly would range between 15% and 30% of that rent. The remaining rent for farmers may be too small to outweigh possible producer price discounts resulting from the costs of segregating GM and non-GM oilseed rape along the supply chain. [source] Consumer responses to new food quality information: are some consumers more sensitive than others?AGRICULTURAL ECONOMICS, Issue 3 2009Zhifeng Gao Choice experiment; Consumer type; Consumer willingness to pay; Food quality information Abstract Missing information prevails in consumer purchase decisions and studies on consumer preferences. Previous research ignores the relationship between consumer types and their responses to new quality attribute information. In this article, consumer responses to new attribute information are compared across consumer groups. Results show that single households with low income are more responsive to new information than married households with high income. Both groups respond to new information more intensively when a cue attribute, Certified U.S. Product, is presented to consumers. [source] The importance of scent and nectar filters in a specialized wasp-pollination systemFUNCTIONAL ECOLOGY, Issue 5 2009Adam Shuttleworth Summary 1.,Plants with open flowers and exposed nectar should attract a wide diversity of flower visitors, yet, for reasons that are not yet well understood, some plants with these ,generalist' floral traits have highly specialized pollination systems. 2.,We investigated this problem in the African milkweed Pachycarpus grandiflorus which has open flowers that produce copious amounts of exposed and concentrated nectar, yet is visited almost exclusively by spider-hunting wasps in the genus Hemipepsis. 3.,These wasps were the only visitors found to consistently carry pollinaria and a cage experiment showed that they are capable of successfully pollinating this plant. Furthermore, experimental hand-pollinations showed that P. grandiflorus is genetically self-incompatible and thus reliant on pollinators for seed set. 4.,We investigated the roles of chemical (nectar and floral scent) and spectral properties in the selective attraction of wasps and the filtering out of other potential flower visitors. Nectar palatability experiments showed that the nectar is unpalatable to honeybees but palatable to the wasps. Choice experiments conducted in the field and using a Y-maze in the laboratory showed that wasps are attracted primarily by scent rather than visual cues. Analysis of scent using Gas Chromatography-Mass Spectrometry showed that these inflorescences produce 36 different compounds, mostly monoterpenes and aliphatics. Analysis of spectral reflectance showed that flowers have similar colouring to the background vegetation. 5.,We conclude that P. grandiflorus is specialized for pollination by Hemipepsis wasps, and in the absence of morphological filters, achieves specialization through unpalatable nectar, cryptic colouring and scent as a selective pollinator attractant. 6.,This study demonstrates that plants whose flowers are not morphologically adapted to exclude particular floral visitors can achieve specialization through non-morphological filters. [source] Using Farmers' Preferences to Assess Development Policy: A Case Study of UgandaDEVELOPMENT POLICY REVIEW, Issue 3 2010Philip A. S. James As part of ongoing economic reforms, the Ugandan government implemented the Plan for the Modernisation of Agriculture (PMA) targeted at reducing rural poverty. This article demonstrates the application of a stated preference method using a choice experiment conducted in 9 sub-counties to assess farmers' preferences for adaptation options and identify areas of the PMA requiring reform to improve its effectiveness. This research shows the importance of microfinance, agricultural extension systems and basic education in farmers' adaptation decisions, and highlights a crucial need to improve local engagement in decision-making. A potentially problematic contradiction between farmers' preferences and some interventions proposed under the PMA is identified. [source] Smallholder Preferences for Agri-environmental Change at the Bhoj Wetland, IndiaDEVELOPMENT POLICY REVIEW, Issue 5 2008Rob Hope Incentive-based approaches have gained policy interest in linking change in agricultural land management with environmental conservation. This article investigates how scheme design influences smallholder farmers' decisions to switch to organic farming to reduce water pollution, drawing on a study at a Ramsar wetland site providing water for the city of Bhopal. Results from a choice experiment suggest that transitional payments are necessary to overcome farmer constraints to adopt organic farming, and that effective land certification has the potential to act as a self-enforcing mechanism linking farmer incomes with wetland conservation benefits. [source] Do You Enjoy Having More than Others?ECONOMICA, Issue 296 2007Survey Evidence of Positional Goods Although conventional economic theory proposes that only the absolute levels of income and consumption matter for people's utility, there is much evidence that relative concerns are often important. This paper uses a choice experiment to measure people's perceptions of the degree to which such concerns matter, i.e. the degree of positionality. Based on a random sample in Sweden, income and cars are found to be highly positional, on average, in contrast to leisure and car safety. Leisure may even be completely non-positional. Potential policy implications are discussed. [source] A cohort study to examine whether time and risk preference is related to smoking cessation successADDICTION, Issue 6 2009Rei Goto ABSTRACT Aim To identify whether time and risk preference predicts relapse among smokers trying to quit. Design A cohort study of smokers who had recently started to quit. Time and risk preference parameters were estimated using a discrete choice experiment (DCE). Participants A total of 689 smokers who began quitting smoking within the previous month. Measurements Time discount rate, coefficient of risk-aversion measured at study entry and duration of smoking cessation measured for 6 months. Findings In the unadjusted model, Cox's proportional hazard regression showed that those with a high time discount rate were more likely to relapse [hazard ratio: 1.18, 95% confidence interval (CI): 1.11,1.25]. A high coefficient of risk-aversion reduced the hazard of relapse (0.96, 0.96,0.97). When adjusted for other predictors of relapse (age, gender, self-efficacy of quitting, health status, mood variation, past quitting experience, the use of nicotine replacement therapy, nicotine dependence), the hazard ratios of time discount rate and the coefficient of risk-aversion is 1.17 (95% CI: 1.10,1.24) and 0.98 (95% CI: 0.97,0.99), respectively. Conclusions Those who emphasize future rewards (time,patient preference) and those who give more importance to rewards that are certain (higher risk-aversion) were significantly more likely to continue to abstain from smoking. [source] Successful Application of Video-Projected Human Images for Signalling to DogsETHOLOGY, Issue 10 2003Péter Pongrácz Dogs were tested (1) in a two-way choice experiment, where the experimenter indicated a baited bowl by pointing; and (2) in a task where the owner was asked to command the dog to execute simple obedience tasks. In expt 1 dogs (n = 10) were tested at first in the presence of the experimenter (three dimensional condition, 3D), that was followed by a series of pointing trials when the life-sized image of the experimenter was projected onto the wall by the means of a video-projector (two dimensional condition, 2D). Dogs performed correctly more often than expected by chance in both 3D and 2D conditions. In expt 2 the commanding owner was either present in the room (3D), or her/his image was projected on the screen (2D), or only her/his voice was audible for the dog through a speaker (0D). The performance of the dogs (n = 10) decreased to great extent comparing the 3D and 0D condition, as the number of different actions the dogs obeyed was significantly less in the 0D condition. However, there was no difference in the number of different actions obeyed in the 3D and 2D conditions. Our results show that dogs readily obey life-sized, interactive moving image in various communicative situtations. We suppose that the difference between 2D and 3D conditions can be attributed partially to the lack of some additional communicative signals as sounds (verbal cues) and odours (from the human), and to some changes in the context. [source] Winners and losers of conservation policies for European eel, Anguilla anguilla: an economic welfare analysis for differently specialised eel anglersFISHERIES MANAGEMENT & ECOLOGY, Issue 2 2010M. DOROW Abstract, Recreational specialisation theory was coupled with a discrete choice experiment to understand eel, Anguilla anguilla L., angler's heterogeneity in their reaction to regulatory changes and the associated welfare changes. Differently specialised eel anglers exhibited distinct preferences for catch variables and eel angling regulations. All anglers preferred slightly to moderately stricter regulations than are currently in place; however, such policies particularly benefited casual eel anglers. In contrast, advanced eel anglers would be most penalised by highly restrictive regulations as indicated by substantial reductions in economic welfare. Aversions to stricter regulations found for advanced anglers contradicted predictions from specialisation theory. From an eel management perspective, the implementation of some simple tools such as increased minimum-size limits will reduce angling mortality on eel and simultaneously increase the welfare of anglers. By contrast, highly restrictive eel angling regulations will result in considerable economic welfare losses of several million , per year for northern Germany alone. [source] Think twice before you book?HEALTH ECONOMICS, Issue 6 2010Modelling the choice of public vs private dentist in a choice experiment Abstract This study concerns the choice of primary dental service provider by consumers. If the health service delivery system allows individuals to choose between public-care providers or if complementary private services are available, it is typically assumed that utilisation is a three-stage decision process. The patient first makes a decision to seek care, and then chooses the service provider. The final stage, involving decisions over the amount and form of treatment, is not considered here. The paper reports a discrete choice experiment (DCE) designed to evaluate attributes affecting individuals' choice of dental-care provider. The feasibility of the DCE approach in modelling consumers' choice in the context of non-acute need for dental care is assessed. The aim is to test whether a separate two-stage logit, a multinomial logit, or a nested logit best fits the choice process of consumers. A nested logit model of indirect utility functions is estimated and inclusive value (IV) constraints are tested for modelling implications. The results show that non-trading behaviour has an impact on the choice of appropriate modelling technique, but is to some extent dependent on the choice of scenarios offered. It is concluded that for traders multinomial logit is appropriate, whereas for non-traders and on average the nested logit is the method supported by the analyses. The consistent finding in all subgroup analyses is that the traditional two-stage decision process is found to be implausible in the context of consumer's choice of dental-care provider. Copyright © 2009 John Wiley & Sons, Ltd. [source] Comparing welfare estimates from payment card contingent valuation and discrete choice experimentsHEALTH ECONOMICS, Issue 4 2009Mandy Ryan Abstract This study presents the first comparison of willingness to pay estimates derived from the payment card (PC) contingent valuation and discrete choice experiment (DCE) methods. A within-sample experiment was used to elicit women's preferences for Chlamydia screening. The willingness to pay estimate derived from the DCE was larger than that derived from the PC. To investigate why the willingness to pay estimates were different, a range of validity tests were conducted. Both methods produced theoretically valid results, and there was no difference in the reported difficulty of completing the tasks. Evidence of a prominence effect was found in the PC responses. Responses to the DCE satisfied tests of non-satiation. Responses to both methods were compared with revealed preference data. There were significant differences between stated screening intention in both methods and actual screening uptake. Future work should address the external validity of stated preference methods. Copyright © 2008 John Wiley & Sons, Ltd. [source] Patient preferences for managing asthma: results from a discrete choice experimentHEALTH ECONOMICS, Issue 7 2007Madeleine T. King Abstract Effective control of asthma requires regular preventive medication. Poor medication adherence suggests that patient preferences for medications may differ from the concerns of the prescribing clinicians. This study investigated patient preferences for preventive medications across symptom control, daily activities, medication side-effects, convenience and costs, using a discrete choice experiment embedded in a randomized clinical trial involving patients with mild,moderate persistent asthma. The present data were collected after patients had received 6 weeks' treatment with one of two drugs. Three choice options were presented, to continue with the current drug, to change to an alternative, hypothetical drug, or to take no preventive medication. Analysis used random parameter multinomial logit. Most respondents chose to continue with their current drug in most choice situations but this tendency differed depending on which medication they had been allocated. Respondents valued their ability to participate in usual daily activities and sport, preferred minimal symptoms, and were less likely to choose drugs with side-effects. Cost was also significant, but other convenience attributes were not. Demographic characteristics did not improve the model fit. This study illustrates how discrete choice experiments may be embedded in a clinical trial to provide insights into patient preferences. Copyright © 2007 John Wiley & Sons, Ltd. [source] Towards a multi-criteria approach for priority setting: an application to GhanaHEALTH ECONOMICS, Issue 7 2006Rob Baltussen Abstract Background: Many criteria have been proposed to guide priority setting in health, but their relative importance has not yet been determined in a way that allows a rank ordering of interventions. Methods: In an explorative study, a discrete choice experiment was carried out to determine the relative importance of different criteria in identifying priority interventions in Ghana. Thirty respondents chose between 12 pairs of scenarios that described interventions in terms of medical and non-medical criteria. Subsequently, a composite league table was constructed to rank order a set of interventions by mapping interventions on those criteria and considering the relative weights of different criteria. Results: Interventions that are cost-effective, reduce poverty, target severe diseases, or target the young had a higher probability of being chosen than others. The composite league table showed that high priority interventions in Ghana are prevention of mother to child transmission in HIV/AIDS control, and treatment of pneumonia and diarrhoea in childhood. Low priority interventions are certain interventions to control blood pressure, tobacco and alcohol abuse. The composite league table lead to a different and more differentiated rank ordering of interventions compared to pure efficiency ratings. Conclusion: This explorative study has introduced a multi-criteria approach to priority setting. It has shown the feasibility of accounting for efficiency, equity and other societal concerns in prioritization decisions, and its potentially large impact on priority setting. Copyright © 2006 John Wiley & Sons, Ltd. [source] Eliciting individual preferences for health care: a case study of perinatal careHEALTH EXPECTATIONS, Issue 1 2010Marjon Van Der Pol PhD Abstract Objective, To demonstrate how a discrete choice experiment (DCE) can be used to elicit individuals' preferences for health care and how these preferences can be incorporated into a cost,benefit analysis. Methods, A DCE which elicited preferences for three perinatal services: specialist nurse appointments; home visits from a trained lay visitor; and home-help. Cost was included to obtain a monetary measure of the value that individuals place on the services. In total, 292 women who had previously participated in a randomized trial of alternative forms of pre-natal care were interviewed. Results, The most preferred service configuration consisted of three nurse appointments and two home visits before birth and 4 h of home-help per week for the first 4 weeks after birth. On average, women are willing to pay $371 for this package. A package that excluded home-help was valued at $122 whilst provision of three nurse appointments only was valued at $97. The predicted uptake of the services ranged from 37% to 93% depending on the woman's experience with the service, whether or not it was her first child and her level of education. Conclusion, The willingness to pay values were much higher than the costs for nurse appointments, suggesting this service produces a net social benefit. The willingness to pay for the package including both the nurse appointments and home visits only just exceeded the costs of the package, suggesting there is a relatively high chance that this package produces a net social loss. [source] Acceptability of willingness to pay techniques to consumersHEALTH EXPECTATIONS, Issue 4 2002Susan J. Taylor PhD Abstract Objective The purpose of this study was to assess and compare the proportion of usable responses and protest votes obtained with two willingness to pay (WTP) techniques, contingent valuation (CV) and discrete choice experiment (DCE) and to assess the acceptability of the techniques to respondents. Setting and participants Pregnant women attending the public antenatal clinics of a Sydney teaching hospital were surveyed. Main variables studied Preference for either Treatment A (artificial rupture of the membranes followed by intravenous oxytocin) or Treatment B (prostaglandin E2 gel followed by oxytocin if necessary) was assessed. Then WTP for the preferred treatments was assessed using CV and WTP for specific attributes of the treatments in the DCE. In addition, the acceptability of the two techniques was compared in terms of responses deemed to be valid according to defined criteria, protest votes and comments recorded by consumers. Results With the CV, 74% of respondents chose gel and their maximum WTP was Aus$178 compared with $133 for the alternative. A total of 68% of responses were deemed to be valid including 5% who may have been expressing a protest vote. With the DCE, respondents were WTP $55 for every 1 h reduction in the length of time from induction to delivery. A total of 72% of responses were deemed valid and only two of these 258 women were considered to have expressed a protest vote. Conclusions Only a small number of women expressed objections to the use of WTP questions in health-care and the majority of women completed both questions successfully. [source] The importance of honeydew as food for larvae of Chrysoperla carnea in the presence of aphidsJOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2008P. A. M. Hogervorst Abstract Larvae of the common green lacewing Chrysoperla carnea are predacious and feed on a wide range of small, soft-bodied arthropods. In addition to their feeding on prey arthropods to cover their nutritional requirements for growth and development, the consumption of non-prey foods such as honeydew has been reported. It is commonly believed that these food supplements are primarily exploited by the larvae when prey is scarce or of low nutritional quality. Here, we assess whether C. carnea larvae also use honeydew when high-quality aphid prey are readily available. In a choice experiment, the feeding behaviour of C. carnea larvae was observed in the presence of both aphids and honeydew. The larvae were starved, aphid-fed, or honeydew-fed prior to the experiment. The time spent feeding on honeydew compared with feeding on aphids was highest for starved larvae and lowest for honeydew-fed larvae. Among the three treatments, the aphid-fed larvae spent the most time resting and the least time searching. In an additional experiment food intake was assessed in terms of weight change when larvae were provided with an ad libitum supply of either aphids or honeydew. Larvae yielded a significant lower relative weight increase on honeydew compared with aphids. The reduced weight increase on honeydew was compensated when larvae were subsequently provided with aphids, but not when honeydew was provided again. This study showed that (i) prior honeydew feeding reduces overall aphid consumption, and (ii) larvae do consume honeydew even after they have been given ad libitum access to aphids. The fact that larvae of C. carnea still use honeydew as a food source in the presence of suitable prey underlines the importance of carbohydrates as foods. [source] Investment Decisions for Retirement SavingsJOURNAL OF CONSUMER AFFAIRS, Issue 3 2010HAZEL BATEMAN We conducted a choice experiment to investigate whether retirement savers follow simple portfolio theory when choosing investments. We modeled experimental survey data on 693 participants using a scale-adjusted version of the latent class choice model. Results show that underlying variability in response was explained by age and "risk profile" score and that preferences varied with income and age. Younger individuals were conventionally risk averse, but older, higher-income individuals may react positively to both higher returns and increasing risk, when risk is presented as widening ranges of possible outcomes. Respondents tended to choose among a few similar investment options. [source] Effect of male age on sperm traits and sperm competition success in the guppy (Poecilia reticulata)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2010C. GASPARINI Abstract Deleterious mutations can accumulate in the germline with age, decreasing the genetic quality of sperm and imposing a cost on female fitness. If these mutations also affect sperm competition ability or sperm production, then females will benefit from polyandry as it incites sperm competition and, consequently, minimizes the mutational load in the offspring. We tested this hypothesis in the guppy (Poecilia reticulata), a species characterized by polyandry and intense sperm competition, by investigating whether age affects post-copulatory male traits and sperm competition success. Females did not discriminate between old and young males in a mate choice experiment. While old males produced longer and slower sperm with larger reserves of strippable sperm, compared to young males, artificial insemination did not reveal any effect of age on sperm competition success. Altogether, these results do not support the hypothesis that polyandry evolved in response to costs associated with mating with old males in the guppy. [source] Non-target habitat exploitation by Trichogramma brassicae (Hym. Trichogrammatidae): what are the risks for endemic butterflies?AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2003D. Babendreier Abstract 1,Trichogramma brassicae Bezdenko is inundatively released against the European corn borer in Switzerland. Because parasitoids dispersing from the release fields might pose a threat to native butterflies, the searching efficiency of T. brassicae was investigated in nontarget habitats. 2,In field studies, T. brassicae was released at rates of 120 000 females/ha. Parasitism of sentinel Ephestia kuehniella egg clusters was 1.6,3.6% in meadows and 2.0,4.0% in flower strips. The respective figures were 57.6,66.7% and 19.2,46.9% in maize, significantly higher than the parasitism rates in the nontarget habitats. Experiments carried out in small field cages confirmed these results: Again, significantly higher parasitism rates were found in maize compared to meadows and flower strips, and also compared to hedgerows (in sleeve cages). 3,To elucidate potential factors underlying the low searching efficiency in nontarget habitats, the behaviour of individual T. brassicae females was investigated on four meadow plants comparatively to maize and a filter paper control. Mean (±SE) walking speed on maize was 2.2 ± 0.2 mm/s, similar to three of the plants tested and filter paper but significantly higher than on Trifolium pratense (0.85 mm/s). A higher turning rate was found on T. pratense, Viola wittrockiana and Plantago lanceolata, in contrast to the longer leaved maize and Alopecurus pratensis. The number of wasps leaving the plant within the observation period differed significantly between plant species, and was twice as high for T. pratense (and the filter paper control) compared to the other plant species. 4,In a choice experiment carried out in a climate cabinet with all five host plant species in cages, we obtained the highest parasitism rates on maize and the lowest parasitism on T. pratense, thus confirming the behavioural observations. 5,In conclusion, there is evidence for a decreased searching efficiency on plants in nontarget habitats compared to maize. However, the data explain only part of the differences found between parasitism in maize compared to nontarget habitats. Other factors, such as the structural complexity of a habitat, may also play a role. We conclude that the risk for butterfly populations in the tested nontarget habitat due to mass released T. brassicae is low. [source] Ghrelin Receptor Antagonism Decreases Alcohol Consumption and Activation of Perioculomotor Urocortin-Containing NeuronsALCOHOLISM, Issue 9 2010Simranjit Kaur Background:, The current therapies for alcohol abuse disorders are not effective in all patients, and continued development of pharmacotherapies is needed. One approach that has generated recent interest is the antagonism of ghrelin receptors. Ghrelin is a gut-derived peptide important in energy homeostasis and regulation of hunger. Recent studies have implicated ghrelin in alcoholism, showing altered plasma ghrelin levels in alcoholic patients as well as reduced intakes of alcohol in ghrelin receptor knockout mice and in mice treated with ghrelin receptor antagonists. The aim of this study was to determine the neuroanatomical locus/loci of the effect of ghrelin receptor antagonism on alcohol consumption using the ghrelin receptor antagonist, D-Lys3-GHRP-6. Methods:, In Experiment 1, male C57BL/6J mice were injected with saline 3 hours into the dark cycle and allowed access to 15% (v/v) ethanol or water for 2 hours in a 2-bottle choice experiment. On test day, the mice were injected with either saline or 400 nmol of the ghrelin receptor antagonist, D-Lys3-GHRP-6, and allowed to drink 15% ethanol or water for 4 hours. The preference for alcohol and alcohol intake were determined. In Experiment 2, the same procedure was followed as in Experiment 1 but mice were only allowed access to a single bottle of 20% ethanol (v/v), and alcohol intake was determined. Blood ethanol levels were analyzed, and immunohistochemistry for c-Fos was carried out to investigate changes in neural activity. To further elucidate the mechanism by which D-Lys3-GHRP-6 affects alcohol intake, in Experiment 3, the effect of D-Lys3-GHRP-6 on the neural activation induced by intraperitoneal ethanol was investigated. For the c-Fos studies, brain regions containing ghrelin receptors were analyzed, i.e. the perioculomotor urocortin population of neurons (pIIIu), the ventral tegmental area (VTA), and the arcuate nucleus (Arc). In Experiment 4, to test if blood ethanol concentrations were affected by D-Lys3-GHRP-6, blood samples were taken at 2 time-points after D-Lys3-GHRP-6 pretreatment and systemic ethanol administration. Results:, In Experiment 1, D-Lys3-GHRP-6 reduced preference to alcohol and in a follow-up experiment (Experiment 2) also dramatically reduced alcohol intake when compared to saline-treated mice. The resulting blood ethanol concentrations were lower in mice treated with the ghrelin receptor antagonist. Immunohistochemistry for c-Fos showed fewer immunopositive cells in the pIIIu of the antagonist-treated mice but no difference was seen in the VTA or Arc. In Experiment 3, D-Lys3-GHRP-6 reduced the induction of c-Fos by intraperitoneal ethanol in the pIIIu but had no effect in the VTA. In the Arc, there was a significant increase in the number of c-Fos immunopositive cells after D-Lys3-GHRP-6 administration, but the antagonist had no effect on ethanol-induced expression of c-Fos. D-Lys3-GHRP-6-pretreatment also did not affect the blood ethanol concentrations observed after a systemic injection of ethanol when compared to saline-pretreated mice (Experiment 4). Conclusions:, These findings indicate that the action of ghrelin on the regulation of alcohol consumption may occur via the pIIIu. [source] Ethanol Preference Is Inversely Correlated With Ethanol-Induced Dopamine Release in 2 Substrains of C57BL/6 MiceALCOHOLISM, Issue 10 2007Vorani Ramachandra Background:, The C57BL/6 mouse model has been used extensively in alcohol drinking studies, yet significant differences in ethanol preference between substrains exist. Differences in ethanol-induced dopamine release in the ventral striatum could contribute to this variability in drinking behavior as dopamine has been implicated in the reinforcing properties of ethanol. Methods:, A 2-bottle choice experiment investigated the difference in ethanol preference between C57BL/6J and C57BL/6NCrl animals. Microdialysis was used to determine dopamine release and ethanol clearance in these 2 substrains after intraperitoneal injections of 1.0, 2.0 and 3.0 g/kg ethanol or saline. Results:, C57BL/6J mice exhibited significantly greater ethanol preference and less ethanol-stimulated dopamine release compared with C57BL/6NCrl mice. The intraperitoneal injections of ethanol caused a significant increase in dopamine in both substrains at all 3 doses with significant differences between substrains at the 2 highest alcohol doses. Saline injections had a significant effect on dopamine release when given in a volume equivalent to the 3 g/kg ethanol dose. Ethanol pharmacokinetics were similar in the 2 substrains at all 3 doses. Conclusions:, Ethanol-induced dopamine release in the ventral striatum may contribute to the differences in alcohol preference between C57BL/6J and C57BL/6NCrl mice. [source] Agency conflicts between board and managerNONPROFIT MANAGEMENT & LEADERSHIP, Issue 2 2009A discrete choice experiment in Flemish nonprofit schools Detecting agency problems is an important task when assessing the effectiveness of a nonprofit organization's governance. A first step is to examine the objectives of principals and agents and determine whether there is a systematic difference between them. Using a discrete choice experiment, we identify the objectives of board chairpersons (principals) and headmasters (agents) of Flemish nonprofit schools. We find systematic differences between the two groups. Of the seven possible objectives set out in the experiment, six are relevant for both headmasters and board chairpersons. For four of these, the preferences of both groups differ significantly. Whereas ideological values play an important role for both the board and the headmaster, they are significantly more important for the board. Both parties dislike having a large number of pupils, and the disutility is larger for the board. With respect to job satisfaction and pupil satisfaction, we find the opposite: while the board is prepared to give up pupil and job satisfaction in favor of the other objectives, these two objectives score very high on the priority list of the headmasters. [source] Public Values for River Restoration Options on the Middle Rio GrandeRESTORATION ECOLOGY, Issue 6 2009Matthew A. Weber Abstract River restoration is a widespread phenomenon. This reflects strong public values for conservation, though missing are studies explicitly justifying restoration expenditures. Public restoration benefits are not well quantified, nor are public preferences among diverse activities falling into the broad category "restoration." Our study estimates public values for restoration on the Middle Rio Grande, New Mexico. Stakeholder meetings and public focus groups guided development of a restoration survey mailed to Albuquerque area households. Four restoration categories were defined: fish and wildlife; vegetation density; tree type; and natural river processes. Survey responses supplied data for both choice experiment (CE) and contingent valuation (CV) analyses, two established environmental economics techniques for quantifying public benefits of conservation policies. Full restoration benefits are estimated at over $150 per household per year via the CE and at nearly $50 per household per year via CV. The CE allows value disaggregation among different restoration categories. The most highly valued category was tree type, meaning reestablishing native tree dominance for such species as Cottonwood (Populus deltoides) and eradicating non-native trees such as Saltcedar (Tamarix ramosissma). The high public values we have found for restoration offer economic justification for intensive riparian management, particularly native plant-based restoration in the Southwest. [source] AN EMPIRICAL ANALYSIS OF CHILD CARE DEMAND IN SWITZERLANDANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 1 2009Silvia Banfi ABSTRACT,:,This paper analyzes the demand of Swiss families for child care facilities. A choice experiment is used to study the effects of the facilities' characteristics as well as socio-economic factors on the selected child care mode. The experimental data are analyzed using a discrete choice model with multinomial logit specification. The results suggest that the demand for extra-familial day care could be considerably higher than that observed from the actual choices constrained by insufficient provision of affordable day care. The price, access, and the quality of service as well as parents' income and education have important impacts on the choice of the mode of care. [source] A multi-attribute trade-off approach for advancing the management of marine wildlife tourism: a quantitative assessment of heterogeneous visitor preferencesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2009Christina A.D. Semeniuk Abstract 1.Wildlife tourism can be prone to unmitigated development to promote visitor satisfaction that is all too often progressed at the cost of ecological integrity. A manager is thus faced with the dual task of enhancing the tourist experience and protecting the wildlife species. Accordingly, this mandate requires research into how tourists would respond to proposed wildlife-management plans. 2.This study examines the heterogeneity of tourist preferences for wildlife management at a stingray-feeding attraction in the Cayman Islands, using a latent class stated preference choice model. A sample of visitors to Stingray City Sandbar (SCS) evaluated hypothetical wildlife viewing experiences in a discrete choice experiment. Its scenarios were characterized by seven attributes such as animal-feeding and handling rules, ecological outcomes, social crowding, and management cost (defined as a conservation access fee). 3.The latent class segmentation identified two groups in the population: approximately 68% preferred the implementation of fairly strict management rules, while the other 32% valued more the maintenance of status quo with its intensive human , wildlife interactions. Despite the differences between the ,pro-management' and the ,pro-current' segments, both exhibited a preference for the continuation of feeding and handling the stingrays (albeit at different levels of intensity) suggesting that one effective way to implement any management actions is to alter the promotional and marketing strategies for SCS. Other survey questions on trip experience, conservation values, and socio-demographics were used to define these classes further, with the main distinguishing trait being the level of concern for potential impacts occurring at SCS. The discrepancies between the two segments became most obvious when calculating their respective market shares of support for alternative management strategies. 4.This approach to determining visitor preferences can help explain how the various segments will be affected by management options, and therefore can provide the basis for developing feasible strategies that will assist wildlife managers in maximizing tourist satisfaction while achieving wildlife-protection goals. Copyright © 2008 John Wiley & Sons, Ltd. [source] Preferences for aspects of a dermatology consultationBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2006J. Coast Summary Background, General practitioners with special interests (GPSIs) are increasingly being used to provide dermatology services in the U.K. Little is known about U.K. dermatology patient attitudes to proposed variations in secondary care service delivery or the values they attach to aspects of the care they receive. Objectives, To quantify preferences for different attributes of care within dermatology secondary care services. Methods, Attributes of care that are important to dermatology patients were derived using in-depth qualitative interviews with 19 patients at different points in the care pathway. A discrete choice experiment using ,best,worst scaling' was sent by post to 119 patients referred to secondary care dermatology services and suitable for GPSI care who had agreed to participate in research. Results, Four attributes were derived from the qualitative work: waiting, expertise, thorough care and convenience. For the discrete choice experiment, 99 patients returned questionnaires, 93 of which contained sufficient data for analysis. All attributes were found to be quantitatively important. The attribute of greatest importance was expertise of the doctor, while waiting time was of least importance. Respondents were willing to wait longer than the current 3 months maximum to receive care that was thorough, 2·1 months to see a team led by an expert and 1·3 months to attend a consultation that is easy to get to. Conclusions, Although the need to reduce outpatient waiting times is a key policy driver behind the expansion of GPSI services, this does not appear to be the most important issue for patients. The thoroughness with which the consultation is provided and the expertise of the clinician seen are higher priorities. [source] Alberta Consumers' Valuation of Extrinsic and Intrinsic Red Meat Attributes: A Choice Experimental ApproachCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2010Bodo Steiner This paper analyzes Alberta consumers' perceptions toward extrinsic and intrinsic attributes of bison and beef steaks. In contrast to published Canadian consumer studies on bison meat that were undertaken prior to May 2003, before the first BSE case of Canadian origin was identified in beef cattle, this study provides a "post-BSE" assessment of consumer perceptions toward selected bison meat attributes. The results from an attribute-based choice experiment provide little support that simple traceability assurance schemes have value to consumers of bison and beef steaks, thus confirming similar findings of earlier beef studies that have employed different methodological approaches. The results also suggest that consumers are willing to pay significant premiums for bison steaks that are certified as being produced without genetically modified organisms, an attribute that has so far been unexplored in previous published bison studies. Le présent article analyse les perceptions des consommateurs de l'Alberta envers des attributs intrinsèques et extrinsèques du bifteck de b,uf et de bison. Contrairement aux études canadiennes sur la consommation de viande de bison publiées avant mai 2003, soit avant l'apparition du premier cas d'ESB dans un troupeau de bovins canadien, la présente étude livre une évaluation « post-ESB » des perceptions des consommateurs envers des attributs sélectionnés de la viande de bison. Les résultats obtenus à partir de la méthode des choix multi-attributs apportent peu d'appui à l'idée voulant que les mécanismes simples d'assurance de la traçabilité aient de la valeur pour les consommateurs de bifteck de bison et de b,uf, ce qui confirme les résultats similaires d'études antérieures sur le b,uf effectuées à l'aide de diverses approches méthodologiques. De plus, les résultats ont montré que les consommateurs sont prêts à payer un supplément appréciable pour du bifteck de bison certifié sans organisme génétiquement modifié (OGM), un attribut qui n'a pas été examiné dans les études sur le bison publiées antérieurement. [source] Does Choice Context Affect the Results from Incentive-Compatible Experiments?CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2009Country-of-Origin Premia in Canola Oil, The Case of Non-GM We seek to design and implement a WTP elicitation instrument closely resembling an actual grocery shopping experience. An incentive-compatible choice experiment is used to elicit values for a non-GM attribute and a country-of-origin attribute of Canola oil. The choice context is varied to assess whether revealed-preference choice experiments are affected by choice variety. A median premium for non-GM Canola oil is found to approximate C$0.45 or C$0.62/liter according to the choice variety context; different country-of-origin effects are also found as choice context varies. Hypotheses as to why these significant effects of choice contexts occur are suggested. Nous cherchons à concevoir et à mettre en application un instrument de révélation de la VDP qui ressemble étroitement aux choix que fait un consommateur lorsqu'il effectue son marché. Nous avons utilisé une méthode expérimentale compatible avec les incitations des participants afin de découvrir la valeur accordée à deux caractéristiques de l'huile de canola: non génétiquement modifiée et étiquetée selon le pays d'origine. La liste des choix est variée afin d'évaluer si les préférences révélées sont influencées par la gamme de choix. La prime médiane de l'huile de canola non génétiquement modifiée est d'environ 0,45 $CAN ou 0,62 $CAN le litre selon les choix proposés. Différents pays d'origine figurent aussi dans cette liste de choix. Nous avons formulé des hypothèses quant aux raisons pour lesquelles la gamme de choix a des effets importants. [source] Do parasitoids diversify in response to host-plant shifts by herbivorous insects?ECOLOGICAL ENTOMOLOGY, Issue 4 2001James T. Cronin Summary 1. For herbivorous insects, the incorporation of a novel host into the diet, and subsequent formation of distinct host associations (races), is thought to be a significant early step in the speciation process. While many studies have addressed this issue, virtually nothing is known about the evolutionary response of natural enemies to herbivore host-race formation. 2. The hypothesis that the parasitoid wasp Eurytoma gigantea (Hymenoptera: Eurytomidae) has formed host races in direct response to the host shift and subsequent host-race formation by its host, the gallmaker Eurosta solidaginis (Diptera: Tephritidae) was tested. Emergence time, mating preference, and female oviposition preference were determined for parasitoids derived from galls of each Eurosta host race. 3. Male and female E. gigantea overlap broadly in their emergence times from each Eurosta host race, suggesting that there is no phenological barrier to gene flow. 4. In choice experiments, female parasitoids did not mate assortatively: females that emerged from one Eurosta host race were equally likely to mate with males from either Eurosta host race. 5. Oviposition behaviour experiments revealed that female parasitoids do not prefer to oviposit on their host race of origin and that there is no overall preference for one host race, even though fitness is higher when parasitoids are reared from Eurosta galls of the Solidago gigantea host race than when reared from Eurosta galls of the Solidago altissima host race. 6. These results suggest that E. gigantea has not diverged in parallel with its host in response to the herbivore host-plant shift. Further studies are needed before the ubiquity of this diversification mechanism can be evaluated fully. [source] Health food versus fast food: the effects of prey quality and mobility on prey selection by a generalist predator and indirect interactions among prey speciesECOLOGICAL ENTOMOLOGY, Issue 2 2000Micky D. Eubanks Summary 1. In order to understand the relative importance of prey quality and mobility in indirect interactions among alternative prey that are mediated by a shared natural enemy, the nutritional quality of two common prey for a generalist insect predator along with the predator's relative preference for these prey was determined. 2. Eggs of the corn earworm Helicoverpa zea (Lepidoptera: Noctuidae) were nutritionally superior to pea aphids Acyrthosiphum pisum (Homoptera: Aphididae) as prey for big-eyed bugs Geocoris punctipes (Heteroptera: Geocoridae). Big-eyed bugs survived four times as long when fed corn earworm eggs than when fed pea aphids. Furthermore, only big-eyed bugs fed corn earworm eggs completed development and reached adulthood. 3. In two separate choice experiments, however, big-eyed bugs consistently attacked the nutritionally inferior prey, pea aphids, more frequently than the nutritionally superior prey, corn earworm eggs. 4. Prey mobility, not prey nutritional quality, seems to be the most important criterion used by big-eyed bugs to select prey. Big-eyed bugs attacked mobile aphids preferentially when given a choice between mobile and immobilised aphids. 5. Prey behaviour also mediated indirect interactions between these two prey species. The presence of mobile pea aphids as alternative prey benefited corn earworms indirectly by reducing the consumption of corn earworm eggs by big-eyed bugs. The presence of immobilised pea aphids, however, did not benefit corn earworms indirectly because the consumption of corn earworm eggs by big-eyed bugs was not reduced when they were present. 6. These results suggest that the prey preferences of generalist insect predators mediate indirect interactions among prey species and ultimately affect the population dynamics of the predator and prey species. Understanding the prey preferences of generalist insect predators is essential to predict accurately the efficacy of these insects as biological control agents. [source] | ||||||||||||||||||||||||||||||||||