This paper develops and applies a structural bioeconomic model of a coastal recreational fishery. We combine a dynamic fish population model, a statistical model of angler catch rates, and a ...recreation demand model to estimate the value of water quality changes for the Atlantic Coast summer flounder fishery. The model predicts that improving water quality conditions in Maryland's coastal bays alone would have relatively small impacts on the fishery as a whole. However, water quality improvements throughout the range of the species could lead to substantial increases in fish abundance and associated benefits to recreational anglers from increased catch rates. We also estimate an alternative version of the catch function, with no direct measure of fish abundance included, and we compare results from this “reduced form” approach to results from our structural model.
Trillions of gallons are withdrawn every year from U.S. rivers, estuaries, lakes, and coastal waters to cool the turbines of power plants and other equipment in manufacturing facilities. In the ...process, large numbers of aquatic organisms die from entrainment into the plant or impingement against the outer portion of the intake structure. In this paper, we develop a generalized age-structured population model with density dependent survival of sub-adult age classes, and we use the model to perform a screening analysis of the effects of entrainment and impingement for 15 harvested fish stocks off the California and Atlantic coasts. Stock sizes are estimated to be depressed by entrainment and impingement by less than 1% in 10 of the 15 cases considered, between 1 and 3% in two cases, and between 20 and 80% in three cases. A variety of sensitivity analyses are conducted to evaluate the influence of several sources of model and parameter uncertainties.
Prison Research From the Inside Newbold, Greg; Ian Ross, Jeffrey; Jones, Richard S. ...
Qualitative inquiry,
04/2014, Letnik:
20, Številka:
4
Journal Article
Recenzirano
A perspective that has often been absent in criminal justice research is that of former prisoners. This article discusses the establishment, in 1997, of “convict criminology,” a group of scholars ...producing research informed by their experiences of crime and the criminal justice process; that is, either those who have served time themselves or who have operated alongside prisoners as professionals in custodial settings. It is argued that such scholars face similar dilemmas to others in terms of emotionalism, but suggests that their emotions are of a different nature. While an “insider” perspective cannot lay claim to scientific “objectivity,” the article argues that the existence of emotion does not invalidate an “insider” criminologist’s views. Rather, the passion engendered by the experience of incarceration can add color, context, and contour to data collection, findings, and analysis and may therefore be regarded as an essential thread in the tapestry of criminological inquiry.
We give a perspective from two practitioners on some of the challenges of addressing sustainability concerns in environmental policy assessments. We focus on the ecological dimension of ...sustainability, which is closely related to the concept of “ecosystem resilience.” First, we discuss several recent benefit–cost analyses conducted by EPA that illustrate many of the practical difficulties analysts have faced when attempting to assess the ecological benefits of proposed regulations. Next, we discuss the importance of increased coordination of policy assessments among offices and agencies that traditionally operate more or less independently. We conclude by using a stylized model to illustrate how using an “adaptive management” approach to designing and evaluating policies can help to avoid some of the limitations of standard policy assessments highlighted in this special section of
Ecological Economics and elsewhere.
The "social cost of carbon" (SCC) is the present value of the stream of future damages from one additional unit of carbon emissions in a particular year. This paper develops a rapid assessment model ...for the SCC. The model includes the essential ingredients for calculating the SCC at the global scale and is designed to be transparent and easy to use and modify. Our goal is to provide a tool to help analysts and decision-makers quickly explore the implications of various modeling assumptions for the SCC. We use the model to conduct sensitivity analyses over some of the key input parameters, and we compare estimates of the SCC under certainty and uncertainty in a Monte Carlo analysis. We find that, due to the combined effects of uncertainty and risk aversion, the certainty-equivalent SCC can be substantially larger than the expected value of the SCC. In our Monte Carlo simulation, the certainty-equivalent SCC is more than four times larger than the expected value of the SCC, and we show that this result depends crucially on how the uncertain preference parameters are handled. We also compare the approximate present value of benefits estimated using the SCC to the exact value of compensating variation in the initial period for a wide range of hypothetical emission reduction policies.
Most landscape design models have been applied to the problem of maximizing species richness in a network of nature reserves. This paper describes a combined hydrologic simulation and landscape ...design model designed to prioritize sites for wetlands restoration, where the objective is to maximize the amount of nutrients in non-point-source runoff attenuated in the restored wetlands. Targeted site selection in four small watersheds in the Central Valley resulted in predicted levels of nitrogen attenuation two to eight times greater than that from maximizing wetland area without consideration of the location of the restoration sites.
A wide variety of environmental stresses can cause density-independent mortality in species populations. One example is cooling-water withdrawals, which kill or injure many aquatic organisms near ...power plants and other industrial facilities. In the United States alone, hundreds of facilities withdraw trillions of gallons from inland and coastal waters every year to cool turbines and other manufacturing equipment. A number of detailed, sitespecific studies of the effects of such cooling-water withdrawals have been conducted over the last 30 years, but only a few generalizations have been proposed in the peer-reviewed literature. In this paper we use a series of basic theoretical models to investigate the potential effects of density-independent mortality on species populations and ecosystems, with particular focus on the effects of cooling-water withdrawals on fish populations, fisheries, and aquatic communities. Among other results, we show that the effects of cooling-water withdrawals on a species will depend on the magnitude of other co-occurring stressors, environmental variability, the nature of the management regime in the associated fisheries, and the position of the species in the food web. The general models in this paper can provide a starting point for further empirical case studies and some preliminary conceptual guidance for decision makers who must choose between alternative policy options for controlling cooling-water withdrawals.
Recreation demand models frequently are used to explain outdoor recreation behavior and to estimate willingness to pay for changes in environmental quality at recreation sites. Among the most ...commonly used recreation demand models are site choice models based on the multinomial logit framework, which account for the spatial relationships between each recreator's home and multiple alternative destinations thereby capturing the substitution possibilities among recreation sites. However, standard applications of this framework typically do not account for the possibility of spatial connections among the sites via movements of the target species, such as fish in connected water bodies in recreational angling applications or terrestrial species in hunting or wildlife viewing applications. In this paper we examine aspects of environmental valuation and natural resource dynamics that generally are addressed separately. Specifically, we show that in such spatially connected systems, a “reduced form” application of the standard site choice modeling approach, using proxy measures of environmental quality rather than direct measures of species abundances, can produce biased estimates of willingness to pay for environmental improvements. Furthermore, we show that under some conditions poorly targeted environmental improvements in spatially connected systems can lead to welfare decreases. In such systems a structural model of recreator site choices and species sorting behavior and population dynamics may be required to fully account for the spatial linkages among sites and the feedback effects between recreators and the target species.
In this reply to the comment by Gerlagh, we confirm an error in our estimate of the certaintyequivalent social cost of carbon (SCC) reported in Newboldet al.(2013), and we discuss the underlying ...conceptual difficulties that arise in conducting a social welfare analysis when preferences are heterogeneous or uncertain. The certainty-equivalent SCC depends crucially on the reference level of per capita consumption used to normalize marginal utility across possible preference parameters, and our estimate of the certainty-equivalent SCC was driven largely by an arbitrary choice of measurement units. All other results from our rapid assessment model are based on the deterministic SCC or its simulated probability distribution, which does not depend on the reference level of per capita consumption.
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