1,720,995 research outputs found
Biofuel from Jatrofa Curcas: environmental sustainability and option value
No full textThe paper considers the use of a non-edible plant, Jatropha curcas (JC), for the production of biofuel as a substitute for traditional fossil fuel. The whole production chain is analyzed; energy and environmental balances are reported. The investment value in biofuel from JC is also studied, and both its intrinsic and option values are calculated. A reference case is evaluated, namely, the cultivation of JC as substitution for conventional fuel in a specific less developed country, Kenya, that lies in the tropical region where JC grows. The investment is modelled as a perpetual investment call option. It is shown that the Net Present Value is positive for a vast range of discount
factors and investment costs, while the option value depends crucially on the parameters of the model. Finally, the case of a relinquishment requirement for the specific land-use is also evaluated by modeling the corresponding American call option value; it is shown that a land-use release requirement does not change the optimal investment strategy
Understanding the risk of an avian flu pandemic: Rational waiting or precautionary failure ?
No full textThe precautionary principle (PP) has been proposed as the proper guide for the decision-making criteria to be adopted in the face of the new catastrophic risks that have arisen in the last decades. This article puts forward a workable definition of the PP based on the so-called alpha-maximin expected utility approach, applying it to the possible outbreak of the avian flu disease among humans. Moreover, it shows how the shortage and/or lack of effective drugs against the infection of the virus A(H5N1) among humans can be considered a precautionary failure
Biofuel from Jatropha curcas: Environmental sustainability and option value
No full textThis paper considers the use of a non-edible plant, Jatropha curcas (J. curcas), for the production of biofuel as a substitute for traditional fossil fuel. It is shown that the net energy balance and greenhouse gases (GHGs) balance are positive. The investment value in biofuel from J. curcas is also studied, and both its intrinsic and option values are calculated. A reference case is evaluated, namely, the cultivation of J. curcas as a substitute for conventional fuel in a specific less-developed country, Kenya, that lies in the tropical region where J. curcas grows. The investment is modeled as a perpetual investment call option. It is shown that the Net Present Value is positive for a vast range of discount factors and investment costs, while the option value depends crucially on the parameters of the model. A positive option value points out those cases in which it is optimal to defer the investment even if it entails a positive and possibly high Net Present Value
Biofuel from Jatrofa Curcas: environmental sustainability and option value
No full textThe paper considers the use of a non-edible plant, Jatropha curcas (JC), for the production of biofuel as a substitute for traditional fossil fuel. The whole production chain is analyzed; energy and environmental balances are reported. The investment value in biofuel from JC is also studied, and both its intrinsic and option values are calculated. A reference case is evaluated, namely, the cultivation of JC as substitution for conventional fuel in a specific less developed country, Kenya, that lies in the tropical region where JC grows. The investment is modelled as a perpetual investment call option. It is shown that the Net Present Value is positive for a vast range of discount
factors and investment costs, while the option value depends crucially on the parameters of the model. Finally, the case of a relinquishment requirement for the specific land-use is also evaluated by modeling the corresponding American call option value; it is shown that a land-use release requirement does not change the optimal investment strategy
Inequality and a Repeated Joint Project
Full text linkAgents voluntarily contribute to an infinitely repeated joint project. We investigate the conditions for cooperation to be a renegotiation-proof and coalition-proof equilibrium before examining the influence of output share inequality on the sustainability of cooperation. When shares are not equally distributed, cooperation requires agents to be more patient than under perfect equality. Beyond a certain degree of share inequality, full efficiency cannot be reached without redistribution. This model also explains the coexistence of one cooperating and one free-riding coalition. In this case, increasing inequality can have a positive or negative impact on the aggregate level of effort.
Environment, Inequality and Collective Action
No full textEfficiency is the hallmark of environmental economics, and though economists are concerned with the environment, primarily because it challenges the efficiency of competitive markets, until now, limited attention has been paid to distributional issues. This excellent collection of essays identifies and addresses key issues surrounding the inequality-environment relationship such as: * Does increasing economic inequality lead to better or worse environmental quality? * Which individual or social features play a role in determining the differentiated impact of changes in the environment? * What impact does economic inequality or social segmentation have on collective action? * How important is the complex economic and social institution in which the inequality-environment takes place? With an impressive array of contributors and an excellent mix of popular and noteworthy topics, this latest addition to the Routledge Siena Studies in Political Economy series will prove essential to economists with an interest in the environment and will be useful to readers with a more general environmental studies background
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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