Did speculation drive oil prices? market fundamentals suggest otherwise

Oil market speculation became an especially popular topic when the price of crude tripled over 18 months to a record high $145 per barrel in July 2008. Of particular interest to many is whether speculators drove oil prices beyond what fundamentals would have otherwise justified. We explore this issue over two Economic Letters. In this article, we look at evidence from the physical market for oil and conclude that fundamentals, and not speculation, were behind the dramatic rise and fall in oil prices. In our companion Economic Letter, we examine the futures market.Supply and demand ; Inventories

Did speculation drive oil prices? futures market points to fundamentals

Oil market speculation became an especially popular topic when the price of crude tripled over 18 months to a record high $145 per barrel in July 2008. Of particular interest to many is whether speculators drove oil prices beyond what fundamentals would have otherwise justified. We explore this issue over two Economic Letters. In this article, we look for evidence in the futures market that would signal speculation primarily drove prices. In our companion Economic Letter, we examine the physical market.Supply and demand ; Inventories ; Macroeconomics

The Composition Of Normative Groups And Diagnostic Decision Making: Shooting Ourselves In The Foot

Purpose: The normative group of a norm-referenced test is intended to provide a basis for interpreting test scores. However, the composition of the normative group may facilitate or impede different types of diagnostic interpretations. This article considers who should be included in a normative sample and how-this decision must be made relative to the purpose for which a test is intended. Method: The way in which the composition of the normative sample affects classification accuracy is demonstrated through a test review followed by a simulation study. The test review examined the descriptions of the normative group in a sample of 32 child language tests. The mean performance reported in the test manual for the sample of language impaired children was compared with the sample's norms, which either included or excluded children with language impairment. For the simulation, 2 contrasting normative procedures were modeled. The first procedure included a mixed group of representative cases (language impaired and normal cases). The second procedure excluded the language impaired cases from the norm. Results: Both the data obtained from test manuals and the data simulation based on population characteristics supported our claim that use of mixed normative groups decreases the ability to accurately identify language impairment. Tests that used mixed norms had smaller differences between the normative and language impaired groups in comparison with tests that excluded children with impairment within the normative sample. The simulation demonstrated mixed norms that lowered the group mean and increased the standard deviation, resulting in decreased classification accuracy. Conclusions: When the purpose of testing is to identify children with impaired language skills, including children with language impairment in the normative sample can reduce identification accuracy.Communication Sciences and Disorder

The Impacts of Macro-Political Structures on the Influence of Municipalities, Traditional Land Users, and Indigenous Governance Structures in EIA Processes

Environmental impact assessments (EIAs) are recognized as a vital planning tool in insuring the sustainable development of resource dependent communities. However, critics point out that the lack of efficiency and efficacy in the process impedes EIAs full potential. One dynamic often criticized for hindering this potential is politics, while there is a consensus that EIAs are inherently political how politics impacts the process is still poorly understood. Part of this is attributed to the limited EIA literature studying the root of politics: power. This thesis will study power and politics in EIA by using an analytical framework based on Anthony Giddens’s structuration theory to examine the impacts of macro political structures on stakeholder dynamics. By conducting an in-depth comparative case study on two EIAs for mining projects, one in Northern Saskatchewan and one in Northern Norway, this thesis identifies that indigenous peoples in the Northern Saskatchewan case had more influence on the EIA process than their Norwegian counterparts, while the local level government in the Norwegian case had more opportunities to influence the EIA process than the local governments in Northern Saskatchewan. The study finds that these differences can largely be attributed to differences in the macro political structures, such as indigenous rights and the authority of different levels of governance, in each country

Untangling effects of human disturbance and natural factors on mortality risk of migratory caribou

Human disturbances are rapidly increasing in northern and Arctic regions, raising concerns about the recovery and persistence of declining caribou (Rangifer tarandus) populations. Yet, the consequences of behavioral responses toward human disturbances on vital rates rarely have been investigated. Herein, we assessed the cumulative and instantaneous effects of human disturbances (roads, human settlements, mines and mining exploration) at different temporal scales on the mortality risk of 254 GPS- collared migratory caribou monitored in two herds, the Rivière-aux-Feuilles (RFH) and Rivière-George (RGH) herds, in northern Québec and Labrador, Canada. We also assessed the relative importance of human disturbances on caribou mortality risk compared with non-anthropogenic factors, including habitat use by caribou, predation risk by gray wolves (Canis lupus), and local weather conditions. Human disturbances alone, exclusive of hunting, had a limited impact on mortality risk of caribou. Repeated exposure to disturbances did not have detectable effects on mortality risk during the early life period (1−7 years old), but more abundant precipitation (RFH) or the use of areas with a higher predation risk (RGH) did so. At the seasonal scale, non-anthropogenic factors, particularly the use of highly selected habitat by caribou and air temperature, had a greater effect than anthropogenic factors on the mortality risk in the RFH. Caribou of the RFH using more frequently higlhy selected habitats decreased their chance of mortality during winter, whereas individuals using warmer areas during summer faced a higher risk of mortality. At the daily scale, we observed that anthropogenic and non-anthropogenic factors generally had either no effect on the daily risk of mortality, or their effects were undistinguishable from the effect of latitude, with which they were highly correlated. The only exception was for the RFH in winter, for which the daily risk of mortality increased 10 folds for each 10-km increment closer to industrial disturbances. Although the impacts of human disturbances on caribou survival were limited to specific regions and areas, we nevertheless detected a negative effect on survival on the RFH, even at the currently low level of human development. Our study highlights the importance of assessing effects of human disturbances at various spatiotemporal scales, and of considering the relative influence of other non-anthropogenic factors to fully understand drives of wildlife populations

AF-algebras and topology of mapping tori

A covariant functor from the category of mapping tori to a category of AF-algebras is constructed; the functor takes continuous maps between such manifolds to stable homomorphisms between the corresponding AF-algebras. We use this functor to develop an obstruction theory for the torus bundles of dimension 2, 3 and 4.Comment: to appear Czechoslovak Math.

Vulnerability to bullying in children with a history of specific speech and language difficulties

This is an electronic version of an article published in Lindsay, Geoff and Dockrell, Julie and Mackie, Clare (2008) Vulnerability to bullying in children with a history of specific speech and language difficulties. European Journal of Special Needs Education, 23 (1). pp. 1-16. European Journal of Special Needs Education is available online at: http://www.informaworld.com/10.1080/0885625070179120

The Embedded Super Star Cluster of SBS0335-052

We analyze the infrared (6-100 micron) spectral energy distribution of the blue compact dwarf and metal-poor (Z=Z_solar/41) galaxy SBS0335-052. With the help of DUSTY (Ivezic et al. 1999), a program that solves the radiation transfer equations in a spherical environment, we evaluate that the infrared (IR) emission of SBS0335-052 is produced by an embedded super-star cluster (SSC) hidden under 10^5 M_solar of dust, causing 30 mag of visual extinction. This implies that one cannot detect any stellar emission from the 2x10^6 M_solar stellar cluster even at near-infrared (NIR) wavelengths. The derived grain size distribution departs markedly from the widely accepted size distribution inferred for dust in our galaxy (the so-called MRN distribution, Mathis et al. 1977), but resembles what is seen around AGNs, namely an absence of PAH and smaller grains, and grains that grow to larger sizes (around 1 micron). The fact that a significant amount of dust is present in such a low-metallicity galaxy, hiding from UV and optical view most of the star formation activity in the galaxy, and that the dust size distribution cannot be reproduced by a standard galactic law, should be borne in mind when interpreting the spectrum of primeval galaxies.Comment: 32 pages, 3 figures,accepted for publication in A

50-60 Hz magnetic fields and cancer, forty years of research: it is time to reassure

In 1979, an epidemiological study carried out in Denver, Colorado first suggested that very weak alternating magnetic fields arising from electrical lines around houses was associated with an increased risk of cancer in children. The potential impact on public health was high, considering the fact that exposure to power-frequency magnetic fields is omnipresent. All power transmission and distribution networks, domestic and industrial wiring, and all kinds of electrical equipment give off magnetic fields. The hypothesis was taken seriously and substantial research budgets have been devoted not only to answering the important question raised by this study but more broadly to identify all other potential health effects of magnetic fields. Since 1979, an exceptional number of scientific studies have been published worldwide. In 2007, the World Health Organization published one of the most comprehensive review so far. The present article summarizes important facts regarding the interaction between a magnetic field and the human body and the key findings from this extensive research looking for a possible link with cancer.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctrico