scholarly journals On the Cost-Effective Design of Agglomeration Bonus Schemes for the Conservation of Multiple Competing Species

2021 ◽  
Vol 9 ◽  
Author(s):  
Martin Drechsler

An important mechanism of species co-existence in spatially structured landscapes is the competition-colonisation trade-off which states that co-existence of competing species is possible if, all other things equal, the better competitor is the worse coloniser. The effectiveness of this trade-off for the facilitation of co-existence, however, is likely to depend on the spatial arrangement of the habitat, because too strong agglomeration of the habitat may overly benefit the strong competitor (being the poor disperser), implying extinction of the inferiour competitor, while too much dispersion of the habitat may drive the superiour competitor (being the inferiour coloniser) to extinction. In working landscapes, biodiversity conservation is often induced through conservation payments that offset the forgone profits incurred by the conservation measure. To control the spatial arrangement of conservation measures and habitats in a conservation payment scheme, the agglomeration bonus has been proposed to provide financial incentives for allocating conservation measures in the vicinity of other sites with conservation measures. This paper presents a generic spatially explicit ecological-economic simulation model to explore the ability of the agglomeration bonus to cost-effectively conserve multiple competing species that differ by their competition strengths, their colonisation rates and their dispersal ranges. The interacting effects of the agglomeration bonus and different species traits and their trade-offs on the species richness in the model landscape are analysed. Recommendations for the biodiversity-maximising design of agglomeration bonus schemes are derived.

2020 ◽  
pp. 1-19
Author(s):  
SAM DESIERE ◽  
LUDO STRUYVEN

Abstract Artificial intelligence (AI) is increasingly popular in the public sector to improve the cost-efficiency of service delivery. One example is AI-based profiling models in public employment services (PES), which predict a jobseeker’s probability of finding work and are used to segment jobseekers in groups. Profiling models hold the potential to improve identification of jobseekers at-risk of becoming long-term unemployed, but also induce discrimination. Using a recently developed AI-based profiling model of the Flemish PES, we assess to what extent AI-based profiling ‘discriminates’ against jobseekers of foreign origin compared to traditional rule-based profiling approaches. At a maximum level of accuracy, jobseekers of foreign origin who ultimately find a job are 2.6 times more likely to be misclassified as ‘high-risk’ jobseekers. We argue that it is critical that policymakers and caseworkers understand the inherent trade-offs of profiling models, and consider the limitations when integrating these models in daily operations. We develop a graphical tool to visualize the accuracy-equity trade-off in order to facilitate policy discussions.


2019 ◽  
Author(s):  
Amanda S Cicchino ◽  
Nicholas A Cairns ◽  
Grégory Bulté ◽  
Stephen C Lougheed

Abstract Trade-offs shaping behavioral variation are often influenced by the environment. We investigated the role that the environment plays in mediating trade-offs using a widespread frog with a conspicuous mating display, Pseudacris crucifer. We first demonstrated, using playback and desiccation experiments, that calling site selection involves a trade-off between sound transmission and desiccation. We then determined the influence of local environmental conditions on the intensity of the trade-off by examining range-wide behavioral and environmental data. We showed that the benefit of improved call transmission is positively influenced by vegetation density and ground cover. Behavioral data are consistent with this relationship: sites with a greater transmission benefit have increased prevalence of arboreally calling males. We also found that the prevalence of arboreal calling behavior increases with relative humidity and air temperature, suggesting an influence of these environmental variables on the desiccation cost of arboreal calling. This study provides a clear example of the role of the environment in mediating trade-off intensities and shaping critical behavioral traits. Local environment mediates the intensity of a trade-off associated with arboreal calling behavior in a treefrog. Combining observational and experimental approaches, we show that arboreal calling behavior increases the transmission of a mating call while potentially subjecting individuals to a rate of desiccation six times greater than terrestrial calling. Local environmental conditions influence both the benefit and the cost of this trade-off, subjecting different populations to varying trade-off intensities and shaping arboreal calling behavior.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jacob R Heldenbrand ◽  
Saurabh Baheti ◽  
Matthew A Bockol ◽  
Travis M Drucker ◽  
Steven N Hart ◽  
...  

Abstract Background Use of the Genome Analysis Toolkit (GATK) continues to be the standard practice in genomic variant calling in both research and the clinic. Recently the toolkit has been rapidly evolving. Significant computational performance improvements have been introduced in GATK3.8 through collaboration with Intel in 2017. The first release of GATK4 in early 2018 revealed rewrites in the code base, as the stepping stone toward a Spark implementation. As the software continues to be a moving target for optimal deployment in highly productive environments, we present a detailed analysis of these improvements, to help the community stay abreast with changes in performance. Results We re-evaluated multiple options, such as threading, parallel garbage collection, I/O options and data-level parallelization. Additionally, we considered the trade-offs of using GATK3.8 and GATK4. We found optimized parameter values that reduce the time of executing the best practices variant calling procedure by 29.3% for GATK3.8 and 16.9% for GATK4. Further speedups can be accomplished by splitting data for parallel analysis, resulting in run time of only a few hours on whole human genome sequenced to the depth of 20X, for both versions of GATK. Nonetheless, GATK4 is already much more cost-effective than GATK3.8. Thanks to significant rewrites of the algorithms, the same analysis can be run largely in a single-threaded fashion, allowing users to process multiple samples on the same CPU. Conclusions In time-sensitive situations, when a patient has a critical or rapidly developing condition, it is useful to minimize the time to process a single sample. In such cases we recommend using GATK3.8 by splitting the sample into chunks and computing across multiple nodes. The resultant walltime will be nnn.4 hours at the cost of $41.60 on 4 c5.18xlarge instances of Amazon Cloud. For cost-effectiveness of routine analyses or for large population studies, it is useful to maximize the number of samples processed per unit time. Thus we recommend GATK4, running multiple samples on one node. The total walltime will be ∼34.1 hours on 40 samples, with 1.18 samples processed per hour at the cost of $2.60 per sample on c5.18xlarge instance of Amazon Cloud.


2016 ◽  
Vol 34 (2) ◽  
pp. 120-135 ◽  
Author(s):  
Arnt O. Hopland ◽  
Sturla F. Kvamsdal

Purpose – The purpose of this paper is to set up and analyze a formal model for maintenance scheduling for local government purpose buildings. Design/methodology/approach – The authors formulate the maintenance scheduling decision as a dynamic optimization problem, subject to an accelerating decay. This approach offers a formal, yet intuitive, weighting of an important trade-off when deciding a maintenance schedule. Findings – The optimal maintenance schedule reflects a trade-off between the interest rate and the rate at which the decay accelerates. The prior reflects the alternative cost, since the money spent on maintenance could be saved and earn interests, while the latter reflects the cost of postponing maintenance. Importantly, it turns out that it is sub-optimal to have a cyclical maintenance schedule where the building is allowed to decay and then be intensively maintained before decaying again. Rather, local governments should focus the maintenance either early in the building’s life-span and eventually let it decay toward replacement/abandonment or first let it decay to a target level and then keep it there until replacement/abandonment. Which of the two is optimal depends on the trade-off between the alternative cost and the cost of postponing maintenance. Originality/value – The paper provides a first formal inquiry into important trade-offs that are important for maintenance scheduling of local public purpose buildings.


Author(s):  
Délcio Faustino ◽  
Maria João Simões

By following the theoretical framework of the surveillance culture this article aims to detail the surveillance imaginaries and practices that individuals have, capturing differences and social inequalities among respondents. We present an in-depth look into surveillance awareness, exploring subjective meanings and the varying awareness regarding commercial, governmental, and lateral surveillance. Furthermore, a detailed analysis is made on how individuals sometimes welcome surveillance, expanding on the cost-benefit trade-off, and detailing it on three distinct trade-offs: the privacy vs. commercial gains/rewards, the privacy vs. convenience and, the privacy vs. security. Lastly, we present a section that explores and analyzes resistance to surveillance.


2014 ◽  
Vol 104 (12) ◽  
pp. 3841-3884 ◽  
Author(s):  
Kate Ho ◽  
Ariel Pakes

We estimate an insurer-specific preference function which rationalizes hospital referrals for privately insured births in California. The function is additively separable in: a hospital price paid by the insurer, the distance traveled, and plan- and severity-specific hospital fixed effects (capturing hospital quality). We use an inequality estimator that allows for errors in price and detailed hospital-severity interactions and obtain markedly different results than those from a logit. The estimates indicate that insurers with more capitated physicians are more responsive to price. Capitated plans send patients further to utilize similar quality, lower-priced hospitals; but the cost-quality trade-off does not vary with capitation rates. (JEL G22, H51, I11, I13, I18, J44)


1987 ◽  
Vol 3 (4) ◽  
pp. 575-586 ◽  
Author(s):  
Akira Sasaki ◽  
John M. Eisenberg

AbstractWe analyzed the cost-effectiveness of nonemergent treatment for esophageal varices commonly used in Japan (endoscopic injection sclerotherapy, nonshunting direct interruption procedure, and selective shunt). We assessed the cost per survivor from the perspective of the Japanese government and other payors. Epidemiologic and economic data from published Japanese literature and from Japanese hospital-cost information were applied in decision analysis. While sclerotherapy is the most cost-effective treatment, the popular surgical procedures save the most lives, thus raising difficult ethical issues regarding trade-offs of cost and quality.


2019 ◽  
Author(s):  
Matthieu Barbier ◽  
Claire de Mazancourt ◽  
Michel Loreau ◽  
Guy Bunin

AbstractThe coexistence of many competing species is a long-standing puzzle in ecology. Classic niche theory explains coexistence by trade-offs between a few essential species traits. Here we study an unexplored frontier of this theory: we assume that coexistence is intrinsically high-dimensional, arising from many traits and trade-offs at once. Species interactions then appear almost random, but their disorder hides a diffuse statistical structure: competitors that become successful start by subtly favoring each other, and partitioning their impacts on other species. We validate our quantitative predictions using data from grassland biodiversity experiments. We conclude that a high biodiversity can be attained through a pattern of collective organization that cannot be understood at the species level, but exhibits the fingerprint of high-dimensional interactions.


2009 ◽  
Vol 21 (1) ◽  
pp. 203-239 ◽  
Author(s):  
Yaw M. Mensah ◽  
Michael P. Schoderbek ◽  
Robert H. Werner

ABSTRACT: The shift toward performance budgeting and outcome measures for public-sector institutions in recent decades has created a need to formally link inputs consumed and outcomes achieved. Given the inherent problems of cost accounting systems in public-sector institutions, we propose a statistical approach to identify the most cost-effective management tools that also recognize the endogeneity between costs and outcomes. The model developed allows for the examination of possible trade-offs that can be exercised by public-sector institutions facing multiple stakeholders with conflicting objectives. Using public schools in New Jersey and a set of variables identified from the education economics literature, we estimate cost and outcome functions to demonstrate empirically the choices made by school district superintendents that trade off the interests of various stakeholders, while seeking to meet the core objectives of the institutions. Our empirical results provide insight on the variables controllable by the superintendents that appear to be used inefficiently, or are subject to institutional constraints that limit the flexibility in input choice assumed by the proposed method. From a management accounting standpoint, the identification of such variables narrows the areas to be focused on in the search for improvements in performance.


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