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Cost Method (cost + method)
Selected AbstractsGrid-induced biases in connectivity metric implementations that use regular gridsECOGRAPHY, Issue 3 2010Adam G. Dunn Graph-theoretic connectivity analyses provide opportunities to solve problems related to the management, design and maintenance of fragmented landscapes. However, several modern connectivity metrics are implemented using algorithms that are affected by a grid-induced bias. When paths through a regular grid are calculated, distance errors are introduced into the metric outputs, with patterns based on the shape and orientation of the underlying grid structure. The bias is significant in the proposed implementations of the conditional minimum transit cost method introduced by Pinto and Keitt, and the effective resistance method introduced by McRae, Dickson, Keitt and Shah. One solution for ameliorating the bias that affects regular grids is to use an irregular lattice to represent the landscape. The purpose of this paper is to serve as a timely reminder of the grid-induced bias and to provide a demonstration of the irregular grid as a simple solution to the problem. [source] Estimating angling effort and participation in a multi-user, inland fishery in South AfricaFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2010B. R. ELLENDER Abstract, Angler counts, on-lake interviews and a household survey were used to estimate angler effort and participation in Lake Gariep, South Africa's largest inland water body. Annual fishing effort was estimated from instantaneous counts at 16392 angler day,1 yr,1. Recreational and subsistence anglers contributed 41 and 59% to the total annual fishing effort, respectively. Household surveys in lakeshore settlements estimated that ,914 anglers fished the lake and minimum daily fishing effort in one of the fishing areas assessed was 77 anglers. As a result of recall bias, these estimates were almost twice as high as those determined by direct counts. A low cost method of assessing participation by applying a mark,recapture model to the proportion of anglers whom had been previously interviewed during eight bimonthly sampling events was tested. The model converged in three of four applications (2 areas × 2 sectors). The mark,recapture method revealed similar numbers of anglers to the estimate of regular anglers (fishing 1,3 times a week) from the household survey and was considered an appropriate estimator for the number of subsistence anglers. Regardless of the assessment method the results show that the resource is of importance to subsistence livelihoods, which is an important management consideration in future fisheries development and rights allocation processes. [source] Testing the convergent validity of the contingent valuation and travel cost methods in valuing the benefits of health careHEALTH ECONOMICS, Issue 2 2002Philip M. Clarke Abstract In this study, the convergent validity of the contingent valuation method (CVM) and travel cost method (TCM) is tested by comparing estimates of the willingness to pay (WTP) for improving access to mammographic screening in rural areas of Australia. It is based on a telephone survey of 458 women in 19 towns, in which they were asked about their recent screening behaviour and their WTP to have a mobile screening unit visit their nearest town. After eliminating missing data and other non-usable responses the contingent valuation experiment and travel cost model were based on information from 372 and 319 women, respectively. Estimates of the maximum WTP for the use of mobile screening units were derived using both methods and compared. The highest mean WTP estimated using the TCM was $83.10 (95% C.I. $99.06,$68.53), which is significantly less than the estimate of $148.09 ($131.13,$166.60) using the CVM. This could be due to the CVM estimates also reflecting non-use values such as altruism, or a range of potential biases that are known to affect both methods. Further tests of validity are required in order to gain a greater understanding of the relationship between these two methods of estimating WTP. Copyright © 2001 John Wiley & Sons, Ltd. [source] Managing Earnings with Intercorporate InvestmentsJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 5-6 2006Øyvind Bøhren Abstract:, We explore to what extent firms deliberately manage their financial reports by exploiting the flexibility of generally accepted accounting principles. Using a sample of Oslo Stock Exchange-listed firms with 20,50% equity holdings in other firms, we find that firms with high financial leverage tend to maximize reported earnings from these investments through their choice between the cost method and the equity method, possibly in an attempt to reduce debt renegotiation costs or to avoid regulatory attention. In contrast, managers do not systematically bias reported earnings to extract private benefits or to signal revised expectations about future cash flows. Firms use different earnings management tools in a consistent way, as the earnings effect of the cost/equity choice is not offset by discretionary accruals. [source] Rent extraction, principal,agent relationships, and pricing strategies: vendor licensing during the 1996 Olympic Games in AtlantaMANAGERIAL AND DECISION ECONOMICS, Issue 8 2001Ralph C. Allen Two-part pricing, price-discrimination, rent creation and extraction, principal,agent theory, and public choice perspectives on public bureaucracies are used to interpret a vendor-license marketing arrangement and controversy arising out of the 1996 Olympic Games in Atlanta, GA. Containing features predicted by principal,agency theory, Atlanta's arrangement with its marketing agent was a response to the behavior of public bureaucracies and a low cost method of converting visitors' consumer surplus to rent, which could be extracted by the marketing agent and then by Atlanta. Atlanta's incentive to enforce vendor property rights was influenced by the nature of the game between Atlanta and prospective vendors. Copyright © 2001 John Wiley & Sons, Ltd. [source] Testing for convergent validity between travel cost and contingent valuation estimates of recreation values in the Coorong, Australia,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2010John Rolfe A number of studies valuing recreation have shown that the travel cost method (TCM) generates higher estimates of value than the contingent valuation method (CVM), even though the latter is commonly associated with potential problems of hypothetical and strategic bias. In this study, both methods have been used to estimate the recreational values associated with the Coorong on the Murray River in south-eastern Australia. Values per adult visitor per recreation day are estimated with the TCM at $149 and with the CVM at $116. A number of methodological and framing issues to explain these value differences are tested. In summary, while no single methodological or framing issue could be identified that would reconcile the difference between TCM and CVM values, it appears likely that there may be a combination of factors that drive the systematic variations in consumer surplus values. The evidence in this study suggests that the most important of these are likely to be the different decision points underpinning data collection and the consideration of substitute sites, strategic responses and the treatment of uncertain responses within the CVM. [source] Duck Hunting and Wetland Conservation: Compromise or Synergy?CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2003Jeff Bennett Duck hunting is an issue , often controversial , that generates both benefits and costs to society. Hunters enjoy benefits from engaging in their sport, while those who have ethical concerns regarding the shooting of ducks endure costs. Some in the community fear that duck hunting puts pressure on the continued ecological viability of the hunted species, while others argue that the demand for hunting provides sufficient economic incentive for wetland conservation. Whether society as a whole should permit or restrict duck hunting is to some extent an empirical question: Are the costs to society of allowing duck hunting greater or less than the benefits it generates? Evidence presented in this paper addresses this question. The benefits enjoyed by people who hunt ducks in the upper south east of South Australia are estimated using the travel cost method. The ethical costs borne by the general community because of duck hunting are estimated using the choice modeling technique. Finally a threshold value analysis is used to assess the activities of Wetlands and Wildlife, a not-for-profit organization that manages wetlands in part for hunting. La chasse au canard est un sujet qui prête souvent à controverse et qui est une source de coûts et d'avantages pour la société. Les chasseurs profitent des avantages que leur procure leur sport, tandis que ceux qui ont des préoccupations d'ordre moral touchant à la chasse subissent des coûts. Certaines personnes dans la communauté craignent que la chasse au canard ne fasse pression sur la viabilitéécologique des espèces chassées. Est-ce que la société dans son ensemble devrait permettre ou limiter la chasse au canard est dans une certaine mesure une question empirique: est-ce que les coûts pour la société de permettre la chasse excèdent ou non les avantages qu'elle procure? Les données présentées dans cet article répondent à cette question. Les avantages reçus par ceux qui chassent le canard dans le haut du sud-est de l'Australie du Sud sont estimés en utilisant la méthode du coût de transport. Les coûts d'ordre moral subis par la communauté dans son ensemble à cause de la chasse au canard sont estimés en utilisant la technique de modélisation des choix. Enfin, une analyse de valeur seuil est utilisée pour évaluer les activités de Zones Aquifères et Nature, un organisme bénévole qui gère les zones aquifères en partie pour la chasse. [source] An Oligonucleotide-based Fluorescence Sensor for Mercury(II) in Aqueous SolutionsCHINESE JOURNAL OF CHEMISTRY, Issue 8 2009Huiwang WU Abstract A highly selective fluorescence sensor was developed for Hg(II) ion detection in aqueous solutions based on the selective binding of Hg(II) ions with a pair of thymine-thymine mismatch. The sensor consists of two DNA probes functionalized with a fluorophore (fluorescein, F) and a quencher (tetramethyl rhodamine, Q) moiety separately. This pair of DNA probes contains two pairs of thymine-thymine mismatches used to detect Hg(II) ions. In the presence of Hg(II) ions, thymine-Hg2+ -thymine was formed between thymine residues of probes. From that, the interaction of the two DNA probes increased. Thus, the DNA probes formed a double-stranded structure. Both the fluorophore and quencher were brought close to each other leading to the fluorescence resonance energy transfer (FRET) between F and Q. Under the optimum conditions, the sensor was used to detect the Hg(II) ions from 50 to 1000 nmol·L,1 with a regression equation y=5281.13,1650.56 lg[Hg2+] (R2=0.985). The linear range covers 100 to 500 nmol·L,1, and the limit of detection (LOD) is 79 nmol·L,1. The disturbance of some co-existing metal ions was explored, and no significant fluorescence quenching in the presence of 1.0 ,mol·L,1 other metal ions was observed. The fluorescence sensor has good sensitivity and selectivity for Hg(II) ions providing a rapid, simple and low cost method for the detection of mercury(II) ions in aqueous solutions. [source] | ||||||||||