172,778 research outputs found
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Misunderstanding Models in Environmental and Public Health Regulation
Computational models are fundamental to environmental regulation, yet their capabilities tend to be misunderstood by policymakers. Rather than rely on models to illuminate dynamic and uncertain relationships in natural settings, policymakers too often use models as “answer machines.” This fundamental misperception that models can generate decisive facts leads to a perverse negative feedback loop that begins with policymaking itself and radiates into the science of modeling and into regulatory deliberations where participants can exploit the misunderstanding in strategic ways. This paper documents the pervasive misperception of models as truth machines in U.S. regulation and the multi-layered problems that result from this misunderstanding. The paper concludes with a series of proposals for making better use of models in environmental policy analysis.The Kay Bailey Hutchison Center for Energy, Law, and Busines
Addressing Uncertainty in TMDLS: Short Course at Arkansas Water Resources Center 2001 Annual Conference
Management of a critical natural resource like water requires information on the status of that resource. The US Environmental Protection Agency (EPA) reported in the 1998 National Water Quality Inventory that more than 291,000 miles of assessed rivers and streams and 5 million acres of lakes do not meet State water quality standards. This inventory represents a compilation of State assessments of 840,000 miles of rivers and 17.4 million acres of lakes; a 22 percent increase in river miles and 4 percent increase in lake acres over their 1996 reports. Siltation, bacteria, nutrients and metals were the leading pollutants of impaired waters, according to EPA. The sources of these pollutants were presumed to be runoff from agricultural lands and urban areas. EPA suggests that the majority of Americans-over 218 million-live within ten miles of a polluted waterbody. This seems to contradict the recent proclamations of the success of the Clean Water Act, the Nation\u27s water pollution control law. EPA also claims that, while water quality is still threatened in the US, the amount of water safe for fishing and swimming has doubled since 1972, and that the number of people served by sewage treatment plants has more than doubled
CURRENT ISSUES AFFECTING TRADE AND TRADE POLICY: AN ANNOTATED LITERATURE REVIEW
This review provides a base of literature describing current issues and research on the impacts of lobalization and the industrialization of agriculture and recent approaches to analyze and model agricultural trade and trade policies. Three key factors of the survey are differentiated goods, global economic integration and international supply chain linkages. The review covers 182 publications, which are presented alphabetically by author with a brief annotation describing how it relates to the above criteria. The articles are also indexed by keyword. A brief summary highlights the documented literature and includes a series of issues for future discussion and research.International Relations/Trade,
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Lessons Learned and Next Steps in Energy Efficiency Measurement and Attribution: Energy Savings, Net to Gross, Non-Energy Benefits, and Persistence of Energy Efficiency Behavior
This white paper examines four topics addressing evaluation, measurement, and attribution of direct and indirect effects to energy efficiency and behavioral programs: Estimates of program savings (gross); Net savings derivation through free ridership / net to gross analyses; Indirect non-energy benefits / impacts (e.g., comfort, convenience, emissions, jobs); and, Persistence of savings
Propagation of epistemic uncertainty in queueing models with unreliable server using chaos expansions
In this paper, we develop a numerical approach based on Chaos expansions to
analyze the sensitivity and the propagation of epistemic uncertainty through a
queueing systems with breakdowns. Here, the quantity of interest is the
stationary distribution of the model, which is a function of uncertain
parameters. Polynomial chaos provide an efficient alternative to more
traditional Monte Carlo simulations for modelling the propagation of
uncertainty arising from those parameters. Furthermore, Polynomial chaos
expansion affords a natural framework for computing Sobol' indices. Such
indices give reliable information on the relative importance of each uncertain
entry parameters. Numerical results show the benefit of using Polynomial Chaos
over standard Monte-Carlo simulations, when considering statistical moments and
Sobol' indices as output quantities
Online Modified Greedy Algorithm for Storage Control under Uncertainty
This paper studies the general problem of operating energy storage under
uncertainty. Two fundamental sources of uncertainty are considered, namely the
uncertainty in the unexpected fluctuation of the net demand process and the
uncertainty in the locational marginal prices. We propose a very simple
algorithm termed Online Modified Greedy (OMG) algorithm for this problem. A
stylized analysis for the algorithm is performed, which shows that comparing to
the optimal cost of the corresponding stochastic control problem, the
sub-optimality of OMG is bounded and approaches zero in various scenarios. This
suggests that, albeit simple, OMG is guaranteed to have good performance in
some cases; and in other cases, OMG together with the sub-optimality bound can
be used to provide a lower bound for the optimal cost. Such a lower bound can
be valuable in evaluating other heuristic algorithms. For the latter cases, a
semidefinite program is derived to minimize the sub-optimality bound of OMG.
Numerical experiments are conducted to verify our theoretical analysis and to
demonstrate the use of the algorithm.Comment: 14 page version of a paper submitted to IEEE trans on Power System
Will Border Carbon Adjustments Work?
Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).The potential for greenhouse gas (GHG) restrictions in some nations to drive emission increases in other nations, or leakage, is a contentious issue in climate change negotiations. We evaluate the potential for border carbon adjustments (BCAs) to address leakage concerns using an economy-wide model. For 2025, we find that BCAs reduce leakage by up to two-thirds, but result in only modest reductions in global emissions and significantly reduce welfare. In contrast, BCA-equivalent leakage reductions can be achieved by very small emission charges or efficiency improvements in nations targeted by BCAs, which have negligible welfare effects. We conclude that BCAs are a costly method to reduce leakage but such policies may be effective coercion strategies. We also investigate the impact of BCAs on sectoral output and evaluate the leakage contributions of trade and changes in the price of crude oil.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors
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