Optical M0bius Strips in Three Dimensional Ellipse Fields: Lines of Linear Polarization

The minor axes of, and the normals to, the polarization ellipses that surround singular lines of linear polarization in three dimensional optical ellipse fields are shown to be organized into Mobius strips and into structures we call rippled rings (r-rings). The Mobius strips have two full twists, and can be either right- or left-handed. The major axes of the surrounding ellipses generate cone-like structures. Three orthogonal projections that give rise to 15 indices are used to characterize the different structures. These indices, if independent, could generate 839,808 geometrically and topologically distinct lines; selection rules are presented that reduce the number of lines to 8,248, some 5,562 of which have been observed in a computer simulation. Statistical probabilities are presented for the most important index combinations in random fields. It is argued that it is presently feasible to perform experimental measurements of the Mobius strips, r-rings, and cones described here theoretically

The contribution of ecological footprinting to planning policy development: using REAP to evaluate policies for sustainable housing construction

The complexity of the sustainable-development policy goal is such that policy makers are searching for tools to enable them to evaluate and develop policy directions. To date, ecological footprinting has been used mainly for raising awareness of environmental impacts but it also has considerable potential as a policy tool, enabling policy makers in their strategic work. The paper presents an application of a specific ecological footprinting development, the REAP (Resource and Energy Analysis Programme) tool, to a current policy issue, the promotion of sustainable construction. Using the London Plan of the Greater London Authority as a case study, it considers the strengths and weaknesses of this approach and how it can contribute to policy development

Principal components analysis in the space of phylogenetic trees

Phylogenetic analysis of DNA or other data commonly gives rise to a collection or sample of inferred evolutionary trees. Principal Components Analysis (PCA) cannot be applied directly to collections of trees since the space of evolutionary trees on a fixed set of taxa is not a vector space. This paper describes a novel geometrical approach to PCA in tree-space that constructs the first principal path in an analogous way to standard linear Euclidean PCA. Given a data set of phylogenetic trees, a geodesic principal path is sought that maximizes the variance of the data under a form of projection onto the path. Due to the high dimensionality of tree-space and the nonlinear nature of this problem, the computational complexity is potentially very high, so approximate optimization algorithms are used to search for the optimal path. Principal paths identified in this way reveal and quantify the main sources of variation in the original collection of trees in terms of both topology and branch lengths. The approach is illustrated by application to simulated sets of trees and to a set of gene trees from metazoan (animal) species.Comment: Published in at http://dx.doi.org/10.1214/11-AOS915 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Competitive Advocacy Opportunity: Zeroing in U.S. Antidumping Enforcement

Almost all countries have antidumping laws which regulate their imports. The United States and other countries enforce these laws within the terms of the World Trade Organization ("WTO"). There is a difference between U.S. enforcement and the enforcement approach of other countries, however. The United States­but not other countries of which I am aware--now uses 'zeroing' in its determination of whether imports are dumped. The use of 'zeroing' will almost always increase the level of any antidumping duty, and will sometimes create a duty where none would have been imposed, had the methodology not been used. All countries test for dumping by attempting to determine whether imports are being sold at less than 'normal' value. Other countries generally do this by directly comparing the average price at which the product is sold in the country of production with the average price at which the same product are sold in the importing market. If the average of the observed prices in the importing country is lower than the average price in the country of production (the 'normal' value), then the foreign firm is said to be dumping. Using zeroing, however, the U.S. treats import price observations above the 'normal' value as if they occurred at the 'normal' value (rather than at their observed level). Transactions at prices below the normal value are treated at their observed levels. The result of zeroing has been to make the U.S. antidumping laws more restrictive than they might appear, with a positive antidumping margin potentially being found if any single transaction occurs below 'normal' value, even if the average of the import prices in the U.S. is much higher than the 'normal' value. The U.S. practice of zeroing has recently been challenged at least six times before the World Trade Organization (WTO), and has generally been found to be inconsistent with the obligations of the United States under the WTO. Many economists feel that the antidumping laws of the U.S., or of any other country, are misguided. Antidumping regulations seem ill suited to play the most likely roles according to which import restrictions might be beneficial: addressing the possibility of predation or strategic trade by foreign firms, or serving as an 'optimal tariff'. Zeroing, therefore, may increase the cost to the U.S. of import protection without any corresponding benefit. The net impact of the zeroing methodology on the United States (compared to antidumping enforcement without zeroing) depends inter alia on the dispersion of the U.S. prices obtained by foreign exporters under dumping investigation by U.S. authorities. One estimate is that the cost of zeroing to the U.S. could be in the range of $46-112 million/year, with the higher end of the range being more likely.Trade, Dumping, Import, Zeroing, United States, WTO

Political Economy of Anglo-French Trade, 1689-1899:Agricultural Trade Policies, Alcohol Taxes and War

Britain – contrary to received wisdom – was not a free trader for most of the 1800s and, despite repeal of the Corn Laws, continued to have higher tariffs than the French until the last quarter of the century War with Louis XIV from 1689 led to the end of all trade between Britain and France for a quarter of a century. The creation of powerful protected interests both at home and abroad (notably in the form of British merchants, and investors in Portuguese wine) led to the imposition of prohibitively high tariffs on French imports -- notably on wine and spirits -- when trade with France resumed in 1714. Protection of domestic interests from import competition allowed the state to raise domestic excises which provided increased government revenues despite almost no increases in the taxes on land and income in Britain. The state ensured compliance not simply through the threat of lower tariffs on foreign substitutes but also through the encouragement of a trend towards monopoly production in brewing and restricted retail sales of beer (which began around 1700 and continued throughout the eighteenth century). This history is analyzed in terms of its effects on British fiscal and commercial policy from the early 1700s to the end of the nineteenth century. The result is a fuller, albeit revisionist account of the rise of the modern state that calls into question a variety of theses in economics and political science that draw on the naive view of a liberal Britain unilaterally moving to free trade in the nineteenth century.Distorted incentives, agricultural and trade policy reforms, national agricultural development, Political economy, agricultural trade policies and war, economic history of Europe, alcohol taxes, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18, H20, N40, N43, N53, O13,

The Implications of ‘Zeroing' on Enforcement of U.S. Antidumping Law

The United States and other countries enforce their antidumping regulations in roughly the same way. There is a difference, however. The United States–but not other countries--now uses ‘zeroing’ in its determination of whether imports are dumped. The use of ‘zeroing’ will almost always increase the level of any antidumping duty, and will sometimes create a duty where none would have been imposed, had the methodology not been used. All countries test for dumping by attempting to determine whether imports are being sold at less than ‘normal’ value. Other countries do this by simply comparing the average price at which the product is sold in the country of production with the average price at which the same product is sold in the importing market. If the average of the observed prices in the importing country is lower than the average price in the country of production (the ‘normal’ value), then the foreign firm is said to be dumping. Using zeroing, however, the U.S. treats import price observations above the ‘normal’ value as if they occurred at the ‘normal’ value (rather than at their observed level). Transactions at prices below the normal value are treated at their observed levels. The result of zeroing has been to make the U.S. antidumping laws more restrictive than they might appear, with a positive antidumping margin potentially being found if any single transaction occurs below ‘normal’ value, even if the average of the import prices in the U.S. is much higher than the ‘normal’ value. The U.S. practice of zeroing has recently been challenged at least six times before the World Trade Organization (WTO), and has generally been found to be inconsistent with the WTO obligations of the United States. The net impact of the zeroing methodology on the United States (compared to antidumping enforcement without zeroing) depends inter alia on the dispersion of the U.S. prices obtained by foreign exporters under dumping investigation. No real estimates of this dispersion exist, but the paper discusses some related evidence which may permit an inference. This evidence is itself quite dispersed, and, therefore, an estimate of the impact and cost of zeroing to the United States has a broad range of uncertainty. But it is plausible that zeroing could add perhaps 3-4 % to the typical U.S. antidumping duty with a cost to the U.S. of around $150 million per year when all existing U.S. antidumping orders were determined by zeroing.Trade, Dumping, Import, Zeroing, United States, WTO