6,780 research outputs found
Regulatory Negotiations and Other Rulemaking Processes: Strengths and Weaknesses from an Industry Viewpoint
In this Article, the author will describe some of the American Petroleum Institute\u27s experiences in recent EPA rulemaking processes, principally rulemakings conducted pursuant to the Clean Air Act. Then I will present my personal views on the advantages and disadvantages of regulatory negotiations compared with other rulemaking processes from the viewpoint of an industry trade association
Sound and Fury: McCloskey and Significance Testing in Economics
For about twenty years, Deidre McCloskey has campaigned to convince the economics profession that it is hopelessly confused about statistical significance. She argues that many practices associated with significance testing are bad science and that most economists routinely employ these bad practices: âThough to a child they look like science, with all that really hard math, no science is being done in these and 96 percent of the best empirical economics. . .â (McCloskey 1999). McCloskeyâs charges are analyzed and rejected. That statistical significance is not economic significance is a jejune and uncontroversial claim, and there is no convincing evidence that economists systematically mistake the two. Other elements of McCloskeyâs analysis of statistical significance are shown to be ill-founded, and her criticisms of practices of economists are found to be based in inaccurate readings and tendentious interpretations of their work. Properly used, significance tests are a valuable tool for assessing signal strength, for assisting in model specification, and for determining causal structure.statistical significance, economic significance, significance testing, regression analysis, econometric methodology, Deirdre McCloskey, Neyman-Pearson testing
Using a cognitive architecture to examine what develops
Different theories of development propose alternative mechanisms by which development occurs. Cognitive architectures can be used to examine the influence of each proposed mechanism of development while keeping all other mechanisms constant. An ACT-R computational model that matched adult behavior in solving a 21-block pyramid puzzle was created. The model was modified in three ways that corresponded to mechanisms of development proposed by developmental theories. The results showed that all the modifications (two of capacity and one of strategy choice) could approximate the behavior of 7-year-old children on the task. The strategy-choice modification provided the closest match on the two central measures of task behavior (time taken per layer, r = .99, and construction attempts per layer, r = .73). Modifying cognitive architectures is a fruitful way to compare and test potential developmental mechanisms, and can therefore help in specifying âwhat develops.
A Microscopic Energy- and Density-Dependent Effective Interaction and its Test by Nucleus-Nucleus Scattering
An effective nucleon-nucleon interaction calculated in nuclear matter from
the Bonn potential has been parametrized in terms of a local density- and
energy-dependent two-body interaction. This allows to calculate the real part
of the nucleus-nucleus scattering potential and to test this effective
interaction over a wide region of densities () produced
dynamically in scattering experiments. Comparing our calculations with
empirical potentials extracted from data on light and heavy ion scattering by
model-unrestricted analysis methods, we find quantitative agreement with the
exception of proton scattering. The failure in this case may be traced back to
the properties of the effective interaction at low densities, for which the
nuclear matter results are not reliable. The success of the interaction at high
overlap densities confirms the empirical evidence for a soft equation of state
for cold nuclear matter.Comment: 8 pages 3 Figures included, to appear in Phys. Lett.
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