1,130 research outputs found

    Economic Growth and Threatened and Endangered Species Listings: A VAR Analysis

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    We conduct several analyses to examine the link between threatened and endangered species listings and macroeconomic activity. Preliminary tests using ordinary least squares are run on both time series data on the national level and cross sectional data at the state level. The analysis is then extended using vector autoregressive (VAR) techniques. VAR results, impulse response functions and variance decompositions are reported to shed more light on the causal relationships between threatened and endangered species, GDP and population. Our results indicate that there is little or no empirical evidence that GDP growth rates lead to changes in the number of threatened and endangered species listings.

    Economic Growth and Threatened and Endangered Species Listings: A VAR Analysis

    Get PDF
    We conduct several analyses to examine the link between threatened and endangered species listings and macroeconomic activity. Preliminary tests using ordinary least squares are run on both time series data on the national level and cross sectional data at the state level. The analysis is then extended using vector autoregressive (VAR) techniques. VAR results, impulse response functions and variance decompositions are reported to shed more light on the causal relationships between threatened and endangered species, GDP and population. Our results indicate that there is little or no empirical evidence that GDP growth rates lead to changes in the number of threatened and endangered species listings. Key Words: Economic growth, endangered and threatened species, vector autoregression

    Stochastic Dominance, Entropy and Biodiversity Management

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    In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case.

    Stochastic Dominance, Entropy and Biodiversity Management

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    In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case. Key Words: Stochastic Dominance, Entropy, Biodiversity Management

    Waiting to Execute: An Optimal Stopping Model of Capital Punishment Stays

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    The focus of this paper is on a specific component of the capital punishment debate: delays in capital punishment. Although the legal justifications for delays in capital punishment cases, such as the right of the writ of habeas corpus, are well known, the analysis of the economic costs and benefits of delaying executions is limited. Fluctuations in the political consensus regarding capital punishment and resulting changes in the imposition of the death penalty in practice suggest that such costs and benefits are important to policymakers. The employment of option value theory is useful when considering the implementation of the death penalty because it involves an action that has uncertain net benefits and that is irreversible.Punishment

    Predicting the movements of permanently installed electrodes on an active landslide using time-lapse geoelectrical resistivity data only

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    If electrodes move during geoelectrical resistivity monitoring and their new positions are not incorporated in the inversion, then the resulting tomographic images exhibit artefacts that can obscure genuine time-lapse resistivity changes in the subsurface. The effects of electrode movements on time-lapse resistivity tomography are investigated using a simple analytical model and real data. The correspondence between the model and the data is sufficiently good to be able to predict the effects of electrode movements with reasonable accuracy. For the linear electrode arrays and 2D inversions under consideration, the data are much more sensitive to longitudinal than transverse or vertical movements. Consequently the model can be used to invert the longitudinal offsets of the electrodes from their known baseline positions using only the time-lapse ratios of the apparent resistivity data. The example datasets are taken from a permanently installed electrode array on an active lobe of a landslide. Using two sets with different levels of noise and subsurface resistivity changes, it is found that the electrode positions can be recovered to an accuracy of 4 % of the baseline electrode spacing. This is sufficient to correct the artefacts in the resistivity images, and provides for the possibility of monitoring the movement of the landslide and its internal hydraulic processes simultaneously using electrical resistivity tomography only

    Pollution Abatement and International Self-Sufficiency

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    Dorfman (1973) anticipates increases in international trade when pollution abatement reduces damage to polluted industries. We simulate the effect of abatement with a Heckscher-Ohlin-Samuelson model of a production on production externality. Both countries are Pigouvian and two levels of abatement effectiveness are endogenized. Although more effective pollution abatement increases total world production of both goods, trade decreases as a proportion of total world production. Our results with possibly greater pollution abatement by larger countries are useful in explaining Rose's (1991) findings that post-1973 increases in real output for large countries are associated with declines in international trade.International TRade; Trade

    Jointly reconstructing ground motion and resistivity for ERT-based slope stability monitoring

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    Electrical resistivity tomography (ERT) is increasingly being used to investigate unstable slopes and monitor the hydrogeological processes within. But movement of electrodes or incorrect placement of electrodes with respect to an assumed model can introduce significant resistivity artefacts into the reconstruction. In this work, we demonstrate a joint resistivity and electrode movement reconstruction algorithm within an iterative Gauss–Newton framework. We apply this to ERT monitoring data from an active slow-moving landslide in the UK. Results show fewer resistivity artefacts and suggest that electrode movement and resistivity can be reconstructed at the same time under certain conditions. A new 2.5-D formulation for the electrode position Jacobian is developed and is shown to give accurate numerical solutions when compared to the adjoint method on 3-D models. On large finite element meshes, the calculation time of the newly developed approach was also proven to be orders of magnitude faster than the 3-D adjoint method and addressed modelling errors in the 2-D perturbation and adjoint electrode position Jacobian

    Corrigendum to “Comparative genomics and pan-genomics of the Myxococcaceae, including a description of five novel species:Myxococcus eversor sp. nov., Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis sp. nov., Myxococcus vastator sp. nov., Pyxidicoccus caerfyrddinensis sp. nov. and Pyxidicoccus trucidator sp. nov.” [Genome Biol. Evol. 12(12) (2020) 2289-2302]

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    FIG. 2.—Scanning electron micrographs of typical myxobacterial cells. (A) strain AM401, (B) strain CA060A. Bars are 5 mm long.Published as part of Chambers, James, Sparks, Natalie, Sydney, Natashia, Livingstone, Paul G, Cookson, Alan R & Whitworth, David E, 2020, Comparative Genomics and Pan-Genomics of the Myxococcaceae, including a Description of Five Novel Species: Myxococcus eversor sp. nov., Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis sp. nov., Myxococcus vastator sp. nov., Pyxidicoccus caerfyrddinensis sp. nov., and Pyxidicoccus trucidator sp. nov., pp. 2289-2302 in Genome Biology and Evolution 12 (12) on page 2294, DOI: 10.1093/gbe/evaa212, http://zenodo.org/record/456162
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