582 research outputs found
Are non-use values distance-independent? Identifying the market area using a choice modelling experiment
This article tests for the effect of distance on non-use values using a Choice Modelling (CM) experiment. Estimating a distance decay relationship for non-use values (NUVs) is important because it would define the market area for an environmental good, i.e. identify the limits for aggregating individual benefit estimates. In contrast to the common definition of NUVs as non-usersĂ values, the CM experiment designs the environmental attributes so that NUV changes can be disentangled from Use Value (UV) changes. The experiment also allows for testing different specification of the distance covariates. Data are obtained from a geographically representative sample. Results show that NUVs do not depend on distance. Aggregation of NUVs is based on income and individualsĂ environmental attitudes.choice modelling, non-use values, aggregation, distance, geographical sampling.
Investigating distance effects on environmental values: A choice modelling approach
This paper describes a Choice Modelling experiment set up to investigate the relationship between distance and willingness to pay for environmental quality changes. The issue is important for the estimation and transfer of benefits. So far the problem has been analysed through the use of Contingent Valuation-type of experiments, producing mixed results. The Choice Modelling experiment allows testing distance effects on parameters of environmental attributes that imply different trade-offs between use and non-use values. The sampling procedure is designed to provide a Ăgeographically balancedĂ sample. Several specifications of the distance covariate are compared and distance effects are shown to take complex shapes. Welfare analysis also shows that disregarding distance produces under-estimation of individual and aggregated benefits and losses, seriously hindering the reliability of costbenefit analyses.choice Modelling techniques, distance, aggregation, sampling, functional forms.
Choice Modelling and laboratory experiments for non-market valuation: a framework
This paper is about combining Choice Modelling and laboratory experimentsincentive-compatible, stated preferences,pivot process, WTP/WTA disparity
Investigating distance effects on environmental values: a choice modelling approach
Analysis of the relationship between distance and willingness to pay (WTP) is important for estimation and transfer of environmental benefits. Several contingent valuation (CV) studies have investigated this topic, but results are mixed. This paper describes a choice modelling (CM) application that estimates distance effects on parameters of three environmental attributes. Combinations of these attributes create different management policies for native vegetation. The CM study is based on a sampling procedure that provides a geographically balanced sample and statistical tests to choose the best specification of the distanceâWTP relationship. Welfare analysis shows that disregarding distance causes under-estimation of individual and aggregated benefits and losses, seriously misdirecting resource allocation.choice modelling, geographical distance, spatial heterogeneity, stratified sample, Environmental Economics and Policy, Resource /Energy Economics and Policy,
A Methodological Approach to the Spatial Aggregation of Values
A Choice Modelling (CM) experiment is developed with the purpose of gaining some insight on how to identify the relevant population for the valuation of an environmental asset. The experiment is based on a survey of Perth residents over the values they attach to Kings Park, the largest urban park in Western Australia, 4/5 of which is native bushland. We design the experiment in order to isolate NUVs form UVs so that trade-offs between attributes of the asset imply tradeoffs between Use Values, Non-Use Values and money. One can then estimate the coefficients for each attribute and analyse the effect of distance on patterns of use. Preliminary results are obtained using data from a pre-survey trial of the questionnaire.Environmental Economics and Policy,
Prediction of maritime pine boards modulus of elasticity by means of sonic testing on green timber
Timber buildings are experiencing a rapid diffusion due to their good performance and their sustainability; however, some steps of structural timber production process, such as drying, are energy-intensive and environmentally impactful, and many wood species are also affected by low yield. Therefore, it would be important to determine the quality of the green material, that is, in wet condition, before undergoing the most impactful and expensive production steps. This paper describes a research aimed at quantifying the variation of the dynamic modulus of elasticity MoEdyn, which is commonly used for structural timber mechanical grading, from wet to dry condition in Sardinian maritime pine boards to be used for the production of laminated timber, and to examine the relationship between wet and dry MoEdyn . The MoEdyn was determined from measurements of the velocity of sonic waves propagating through the boards. The results show that the dry MoEdyn can be estimated starting from boards sonic testing in the wet condition, so providing a basis for implementing Sardinian maritime pine pre-grading in order to obtain the reduction of manufacturing costs, the abatement of environmental impact, and the increase of structural grade yield
Analisi morfo-funzionale dello scheletro post-craniale di Ziphius cavirostris, Mesoplodon bowdoini e Hyperoodon ampullatus (Cetacea: Ziphhidae)
Sulla base di osservazioni dirette, gli zifidi sono i cetacei che si spingono a maggiori profonditĂ (superano i 1900m) e per una durata maggiore (1 h circa). Tra le tendenze evolutive dello scheletro degli zifidi compaiono caratteristiche peculiari, quali una pinna caudale la cui superficie idrodinamica è evidentemente poco sviluppata, pinne pettorali di ridotte dimensioni, una testa ridotta se paragonata alla lunghezza totale dellâanimale e un rostro particolarmente denso. Durante la maturazione dellâindividuo il rostro è soggetto a pachiostosi e osteosclerosi, caratteristiche dimorfiche e soggette a variazioni ontogenetiche. Ă stato proposto che questa struttura si sia evoluta per agevolare lâimmersione; si tratta infatti dellâosso piĂš denso in natura (in M. densirotris la densitĂ di questa struttura è di 2.60 g/cm3). Sulla base di questa ipotesi, è stata condotta unâanalisi morfo-funzionale della colonna vertebrale, al fine di stabilire se lâincremento ontologico della densitĂ del rostro è enfatizzato da una ridotta densitĂ dello scheletro post-craniale. Per ogni vertebra del rachide degli zifidi esaminati (Z. cavirostris, M. bowdoini e H. ampullatus) sono stati misurati la lunghezza, lâaltezza e la larghezza del corpo vertebrale (CL, CH e CW rispettivamente), lâaltezza dei processi neurali (NPH, NAH e NSH) e il grado di inclinazione (NAI e NSI), tenendo conto del fatto che questi processi offrono punti dâinserzione per i muscoli coinvolti nella spinta propulsiva, quali il muscolo multifido e il lunghissimo del dorso. Per ognuna delle specie esaminate è stato calcolato il momento di forza e il momento di resistenza alla curvatura dorso-ventrale e latero-laterale ed è stato stimato il baricentro delle componenti assili. Il baricentro dello scheletro assile è stato stimato anche per Delphinus delphis â un piccolo delfinide che non si immerge oltre i 200 m di profonditĂ â ed è stato confrontato con quello degli zifidi presi in esame, avvalorando lâipotesi di partenza (il baricentro degli zifidi è notevolmente spostato in avanti). Ă stata eseguita una TAC (Tomografia Assile Computerizzata) sulla prima vertebra caudale (Ca1) dello zifio e del delfino comune, che ha messo in evidenza differenze notevoli tra le due specie, riconducibili probabilmente alla loro ecologia e quindi alla profonditĂ preferenziale e alla dinamica del nuoto: in Z. cavirostris si osserva Ďmean= - 423.03, mentre in D. delphis Ďmean= - 104.54). In seguito alla micro-TAC, eseguita sulle falangi degli zifidi e del delfino comune, è emerso che M. bowdoini è caratterizzato da un tessuto trabecolare rarefatto (BV/TV=0.19, Conn.=846.88 e TbSpmean=0.82). Le trabecole di tutte le falangi esaminate sono tendenzialmente tubulari (SMI>2, tranne per H. ampullatus per il quale SMI<0)
Feasibility of a Local Production Chain for Structural Timber in Sardinia, Italy
The construction sector is currently responsible for over 30% of the consumption of natural resources and the release of solid waste and pollution into the environment. This situation is even more serious in closed communities such as islands, economically highly dependent on the outside world. One of the possible interventions to reverse this trend is the use of eco-sustainable construction materials such as wood, produced through supply chains with a low environmental impact. This paper reports on a research activity that analyzed the feasibility of implementing a sustainable local supply chain in Sardinia to produce Cross-Laminated Timber (CLT) panels made of locally grown wood. This research has experimentally carried out the entire supply chain process: (i) choice and collection of the raw material in the forest for producing strength-graded boards to manufacture laminated timber, (ii) manufacturing of CLT panel prototypes, and (iii) determination of CLT panelsâ mechanical performance through laboratory tests. This experimentation allowed, on the one hand, to evaluate the performance and competitiveness of CLT panels made of local wood, and on the other hand, to identify the criticalities that currently hinder the implementation of this supply chain in Sardinia, and to propose possible actions to solve them
The Historical Evolution of the German Present Perfect from the Perspective of Complexity Theory and Emergent Grammar
The purpose of this study is to understand the meaning of the present perfect in Modern German and also, to trace its development in the early stages of German. Therefore, the synchronic analysis, in which I analyze articles from a famous German magazine, is combined with the diachronic study of the present perfect attestations in Old High German and Middle High German. This study is conducted within a Complexity-Theory and Emergent Grammar approach in which languages are viewed as dynamic system that changes over time, and grammar is seen as an epiphenomenon and a result of communicative needs among speakers
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