2,119 research outputs found
Development of coatings to control electroosmosis in zero gravity electrophoresis
A major problem confronting the operation of free fluid electrophoresis in zero gravity is the control of electrokinetic phenomena and, in particular, electroosmosis. Due to the severity of counter flow, as a result of electroosmosis, the electrical potential developed at the surface of shear must be maintained at near, or as close to, zero millivolts as possible. Based upon this investigation, it has been found that the amount of bound water or the degree of hydroxylation plays a major role in the control of this phenomena. Of necessity, factors, such as adhesion, biocompatibility, protein adsorption, and insolubility were considered in this investigation because of the long buffer-coating exposure times required by present space operations. Based upon tests employing microcapillary electrophoresis, it has been found that gamma amino propyl trihydroxysilane produced a coating which provides the lowest potential (minus 3.86 mv) at the surface of shear between the stationary and mobile layers. This coating has been soaked in both borate and saline buffers, up to three months, in a pH range of 6.5 to 10 without deleterious effects or a change in its ability to control electrokinetic effects
Location Efficient Mortgages: Is the Rationale Sound?
Location efficient mortgages (LEM) programs are an increasingly popular approach to combating urban sprawl. LEMs allow families who want to live in densely-populated, transit-rich communities to obtain larger mortgages with smaller downpayments than traditional underwriting guidelines allow. LEMs are premised on the proposition that homeowners in such "location efficient" areas can safely be allowed to breach underwriting guidelines designed to prevent mortgage default because they have lower than average automobile-related transportation expenses and more income available for mortgage payments. This paper employs records of over 8,000 FHA-insured mortgages matched with data on various measures of location efficiency to test this proposition. Our results suggest that it does not hold and that LEMs—like other low-downpayment mortgage programs—will raise mortgage default rates. This cost must be weighed against any potential anti-sprawl benefits LEMs may have.urban sprawl, location efficiency, mortgage, default
The Definition and Choice of Environmental Commodities for Nonmarket Valuation
Economic analyses of nature must somehow define the “environmental commodities” to which values are attached. This paper articulates a set of principles to guide the choice and interpretation of nonmarket commodities. We describe how complex natural systems can be decomposed consistent with what can be called “ecological production theory.” Ecological production theory--like conventional production theory--distinguishes between biophysical inputs, process, and outputs. We argue that a systems approach to the decomposition and presentation of natural commodities can inform and possibly improve the validity of nonmarket environmental valuation studies. We raise concerns about the interpretation, usefulness, and accuracy of benefit estimates derived without reference to ecological production theory.nonmarket valuation, stated preference, revealed preference, commodities, endpoints
Measuring the Value of Health Improvements from Great Lakes Cleanup
Exposure to pollutants in the Great Lakes Region can have significant effects on human health. Some forms of pollution affect humans directly, through the air we breathe and water we drink. Other forms of pollution affect humans indirectly, for example through consumption of contaminated fish. In this paper the authors describe methods to measure health benefits in monetary and nonmonetary terms in the context of reductions in pollutants as part of a program to improve the environment in the Great Lakes. The paper is meant to be an introduction to this topic for a general audience interested in the Great Lakes.
Intel's XL Permit: A Framework for Evaluation
The paper develops a framework to evaluate permits granted to firms under the Environmental Protection Agency's Project XL � with emphasis on the novel air permit granted to the Intel Corporation. We describe the permit, the process that created it, and the types of costs and benefits likely to arise from this type of "facility-specific" regulatory arrangement. Among other things, the paper describes the permit's impact on environmental quality, production costs, transaction costs, and Intel's strategic market position. The paper also considers how an estimate of the costs and benefits � both to Intel and society � might be estimated. While facility-specific regulation typically conjures images of production cost savings as processes are re-engineered and low-cost abatement strategies pursued, the Intel case highlights perhaps a more important source of benefit: flexibility in the form of streamlined permitting. Flexibility in this form allows for accelerated product introductions, with potentially significant benefits to the firm and possibly to society.
Efficiency and Political Economy of Pollution Control with Ancillary Benefits: An Application to NOx Control in the Chesapeake Bay Airshed
This paper examines implications for cost-effective allocation of pollution controls when preferences of coalitions organized along regional lines, or according to preferences for air vs. water quality improvements, are accounted for. Results are compared to a base case in which NOx emissions reductions must satisfy only a water quality standard, and total costs are minimized over emissions sources. Relative to base-case result that marginal control costs must be equal across sources, stronger relative preferences for air imply shifting of control toward sources that produce greater ancillary benefits to air quality. Regional differences may require side payments to induce cooperation where benefits are low, but this will not affect how controls themselves should be allocated.
Public Support for Pollution Fee Policies for Motor Vehicles: Survey Results
In this paper we report on the results of a telephone survey conducted in Southern California during August and September 1996. The purpose of the survey was to inform respondents about a set of rather complex pricing policies designed to reduce motor vehicle emissions and to estimate respondent support for those policies. After receiving extensive information about these policies, respondents were polled on whether they would support, i.e., vote for, any or all of these options. The pollution fee survey elicited support for a plan that levied a fee on vehicles in the region, depending on the vehicle's emissions per mile and on the miles driven. The sample was then split in two, with half the respondents being told that a portion of the revenues would be returned to the public in the form of reductions in motor vehicle fees or sales tax reductions, and half told that these returns would be made in the form of coupons. Nearly 40 percent of respondents agreed to support the base plan (42 percent of those expressing an opinion). More than 50 percent supported the fees with rebates, including support of 54 percent when all the available revenues are returned to the public (57 percent of the sample expressing an opinion). Support for the coupon policy was intermediate between the base and rebate policies, attracting 42 percent of the sample (45 percent of those expressing an opinion). Statistical analyses were performed on the data to explain the voting patterns observed. Generally, the levels of support were significantly affected by the design features of the plans, such as the size of the fee paid and the rebate, as well as by a host of socio-demographic and perceptual variables, such as ethnicity, age, political affiliation, expected efficacy of the policy, and the degree to which air pollution affects the respondent or his or her family. Examination of these statistical results may be useful in the development of pollution fee programs to present to the public, as well as in the design of public information campaigns and the allocation of marketing resources to win support for these programs.
Overcoming Public Aversion to Congestion Pricing
Transportation authorities have consistently failed to employ economic incentives on major roadways--i.e. time-of-day pricing or "congestion fees"--to internalize the costs of congestion. In principle at least, such tolls can easily be shown to increase social welfare by making motorists pay something closer to the full social costs of their driving decisions. In addition, recent advances in electronics make it possible to implement such fees fairly cheaply and non-intrusively. While these same authorities generally understand and acknowledge the case for using congestion fees, they also claim that their use is politically infeasible because too many motorists would suffer large increases in commuting costs. This is the puzzle: If congestion tolls truly do advance social welfare, why is it so difficult to find a way to implement them? Two common explanations for this difficulty are the following: (i) The public perceives, or politicians fear that they would perceive, such fees simply as tax increases. If so, they might be responsive to an explicit promise to return the money in some way. (ii) Motorists dislike congestion fees because they find them coercive, in that they often have few if any practical alternatives to paying the fee. If so, then a policy option that offers motorists a choice of toll lanes and the more customary free lanes may be more attractive than a policy that policy of tolls on all lanes. We have completed a survey of Southern California residents designed to test these hypotheses. Unlike most opinion surveys on congestion pricing, our survey was quite explicit about the fate of the collected revenues. For example, we presented respondents with policies that returned a substantial portion of the revenues to the public, either in the form of cash (through reductions in sales taxes and vehicle registration fees or through income tax credits) or in the form of coupons to be used for vehicle emissions equipment repair, transit, and the like. In the past, most surveys have not been explicit about the revenues, or they have stated that revenue use was to be for improved highways, transit, or other public purposes. We find that a promise to offset the imposition of congestion fees by other taxes can result in a 7 percentage point increase in support for congestion pricing policies, and the restriction of congestion pricing to a single lane on a freeway attracts from 9 to 17 percentage points of additional support.
Cost-Benefit Analysis and Regulatory Reform: An Assessment of the Science and Art
The continuing efforts in the 104th Congress to legislate requirements for cost-benefit analysis (CBA) and the revised Office of Management and Budget guidelines for the conduct of such assessments during a regulatory rulemaking process highlight the need for a comprehensive examination of the role that CBA can play in agency decision-making. This paper summarizes the state of knowledge regarding CBA and offers suggestions for improvement in its use, especially in the context of environmental regulations.
The Benefits and Costs of Fish Consumption Advisories for Mercury
Mercury contamination of the Chesapeake Bay is a concern to health authorities in the region. We evaluate the economic and health effects of postulated recreational and commercial fishing advisories for striped bass on the Maryland portion of the bay. Awareness of and response to the advisory is estimated using a meta-analysis of the literature. Three values are estimated: welfare losses to recreational anglers, welfare losses in the commercial striped bass fishery, and health benefits. An estimate of percentage of consumer surplus loss is applied to the value of all fishing days in the bay to estimate recreational welfare loss. Welfare losses to the commercial fishery are estimated based on a model of supply and demand. Health benefits are estimated using estimated exposure and epidemiological relationships, and while potentially large, are highly uncertain. Results also suggest most individuals are below advisory standards ex ante, such that advisories should target high-frequency consumers.fisheries, mercury, advisories, recreation, health benefits
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