The elasticity of trade : estimates and evidence

Quantitative results from a large class of structural gravity models of international trade depend critically on a single parameter governing the elasticity of trade with respect to trade frictions. We provide a new method to estimate this elasticity and illustrate the merits of our approach relative to the estimation strategy of Eaton and Kortum (2002). We employ this method on data for 123 developed and developing countries for the year 2004 using new disaggregate price and trade flow data. Our benchmark estimate for all countries is approximately 4.5, nearly 50 percent lower than the alternative estimation strategy would suggest. This difference implies a doubling of the measured welfare costs of autarky across a large class of widely used trade models

Study of the winter 2005 Antarctica polar vortex

During winter and springtime, the flow above Antarctica at high altitude (upper troposphere and stratosphere) is dominated by the presence of a vortex centered above the continent. It lasts typically from August to November. This vortex is characterized by a strong cyclonic jet centered above the polar high. In a recent study of our group (Hagelin et al., 2008) of four different sites in the Antarctic internal plateau (South Pole, Dome C, Dome A and Dome F), it was made the hypothesis that the wind speed strength in the upper atmosphere should be related to the distance of the site to the center of the Antarctic polar vortex. This high altitude wind is very important from an astronomical point of view since it might trigger the onset of the optical turbulence and strongly affect other optical turbulence parameters. What we are interested in here is to localize the position of the minimum value of the wind speed at high altitude in order to confirm the hypothesis of Hagelin et al. (2008).Comment: 3rd ARENA conference, 11-15 May 2009 EAS Publication Serie

The Elasticity of Trade: Estimates and Evidence

Quantitative results from a large class of international trade models depend critically on the elasticity of trade with respect to trade frictions. We develop a simulated method of moments estimator to estimate this elasticity from disaggregate price and trade-flow data using the Ricardian model. We motivate our estimator by proving that the estimator developed in Eaton and Kortum (2002) is biased in any finite sample. We quantitatively show that the bias is severe and that the data requirements necessary to eliminate it in practice are extreme. Applying our estimator to new disaggregate price and trade-flow data for 123 countries in the year 2004 yields a trade elasticity of roughly four, nearly fifty percent lower than Eaton and Kortum’s (2002) approach. This difference doubles the welfare gains from international trade.elasticity of trade, bilateral, gravity, price dispersion, indirect inference

Liraglutide for the treatment of type 2 diabetes : a single technology appraisal

This paper presents a summary of the Evidence Review Group (ERG) report into the clinical effectiveness and cost-effectiveness of liraglutide in the treatment of type 2 diabetes mellitus, based upon the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The manufacturer proposed the use of liraglutide as a second or third drug in patients with type 2 diabetes whose glycaemic control was unsatisfactory with metformin, with or without a second oral glucoselowering drug. The submission included six manufacturer-sponsored trials that compared the efficacy of liraglutide against other glucose-lowering agents. Not all of the trials were relevant to the decision problem. The most relevant were Liraglutide Effects and Actions in Diabetes 5 (LEAD-5) (liraglutide used as part of triple therapy and compared against insulin glargine) and LEAD-6 [liraglutide in triple therapy compared against another glucagon like peptide-1 (GLP-1) agonist, exenatide]. Five of the six trials were published in full and one was then unpublished. Two doses of liraglutide, 1.2 and 1.8 mg, were used in some trials but in the two comparisons in triple therapy, against glargine and exenatide, only the 1.8-mg dose was used. Liraglutide in both doses was found to be clinically effective in lowering blood glucose concentration [glycated haemoglobin (HbA1c)], reducing weight (unlike other glucose-lowering agents, such as sulphonylureas, glitazones and insulins, which cause weight gain) and also reducing systolic blood pressure (SBP). Hypoglycaemia was uncommon. The ERG carried out meta-analyses comparing the 1.2- and 1.8-mg doses of liraglutide, which suggested that there was no difference in control of diabetes, and only a slight difference in weight loss, insufficient to justify the extra cost

Effects of Error Correction During Assessment Probes on the Acquisition of Sight Words for Students with Moderate Intellectual Disabilities

Simultaneous prompting is an errorless learning strategy designed to reduce the number of errors students make; however, research has shown a disparity in the number of errors students make during instructional versus probe trials. This study directly examined the effects of error correction versus no error correction during probe trials on the effectiveness and efficiency of simultaneous prompting on the acquisition of sight words by three middle school students with moderate intellectual disabilities. A single-case adapted alternating treatments design (Sindelar, Rosenberg, & Wilson, 1985) was employed to examine the effects of error correction during probe trials in order to reduce error rates. A functional relation was established for two of the three students for the use of error correction during probe sessions to reduce error rates. Error correction during assessment probes required fewer sessions to criterion, resulted in fewer probe errors, resulted in a higher percentage of correct responding on the next subsequent trial, and required less total probe time. For two of the three students, probes with error correction resulted in a more rapid acquisition rate requiring fewer sessions to criterion

Migration costs and observational returns to migration in the developing world

Recent studies find that observational returns to rural-urban migration are near zero in three developing countries. We revisit this result using panel tracking surveys from six countries, finding higher returns on average. We then interpret these returns in a multi-region Roy model with heterogeneity in migration costs. In the model, the observational return to migration confounds the urban premium and the individual benefits of migrants, and is not directly informative about the welfare gain from lowering migration costs. Patterns of regional heterogeneity in returns, and a comparison of experimental to observational returns, are consistent with the model’s predictions

Evidence review : liraglutide for the treatment of type 2 diabetes

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of liraglutide in the treatment of type 2 diabetes mellitus, based upon the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal process. The manufacturer proposed the use of liraglutide as a second or third drug in patients with type 2 diabetes whose glycaemic control was unsatisfactory with metformin, with or without a second oral glucose-lowering drug. The submission included six manufacturer-sponsored trials that compared the efficacy of liraglutide against other glucose-lowering agents. Not all of the trials were relevant to the decision problem. The most relevant were Liraglutide Effects and Actions in Diabetes 5 (LEAD-5) (liraglutide used as part of triple therapy and compared against insulin glargine) and LEAD-6 [liraglutide in triple therapy compared against another glucagon-like peptide-1 agonist, exenatide]. Five of the six trials were published in full and one was then unpublished. Two doses of liraglutide, 1.2 and 1.8 mg, were used in some trials, but in the two comparisons in triple therapy, against glargine and exenatide, only the 1.8-mg dose was used. Liraglutide in both doses was found to be clinically effective in lowering blood glucose concentration [glycated haemoglobin (HbA1c)], reducing weight (unlike other glucose-lowering agents, such as sulphonylureas, glitazones and insulins, which cause weight gain) and also reducing systolic blood pressure (SBP). Hypoglycaemia was uncommon. The ERG carried out meta-analyses comparing the 1.2- and 1.8-mg doses of liraglutide, which suggested that there was no difference in control of diabetes, and only a slight difference in weight loss, insufficient to justify the extra cost. The cost-effectiveness analysis was carried out using the Center for Outcomes Research model. The health benefit was reported as quality-adjusted life-years (QALYs). The manufacturer estimated the cost-effectiveness to be £15,130 per QALY for liraglutide 1.8 mg compared with glargine, £10,054 per QALY for liraglutide 1.8 mg compared with exenatide, £10,465 per QALY for liraglutide 1.8 mg compared with sitagliptin, and £9851 per QALY for liraglutide 1.2 mg compared with sitagliptin. The ERG conducted additional sensitivity analyses and concluded that the factors that carried most weight were: in the comparison with glargine, the direct utility effects of body mass index (BMI) changes and SBP, with some additional contribution from HbA1c in the comparison with exenatide, HbA1c, with some additional effects from cholesterol and triglycerides in the comparison with sitagliptin, HbA1c and direct utility effects of BMI changes. The European Medicines Agency has approved liraglutide in dual therapy with other oral glucose-lowering agents. NICE guidance recommends the use of liraglutide 1.2 mg in triple therapy when glycaemic control remains or becomes inadequate with a combination of two oral glucose-lowering drugs. The use of liraglutide 1.2 mg in a dual therapy is indicated only in patients who are intolerant of, or have contraindications to, three oral glucose-lowering drugs. The use of liraglutide 1.8 mg was not approved by NICE. The ERG recommends research into the (currently unlicensed) use of liraglutide in combination with long-acting insulin

HZTool and Rivet: Toolkit and Framework for the Comparison of Simulated Final States and Data at Colliders

A common problem in particle physics is the requirement to reproduce comparisons between data and theory when the theory is a (general purpose) Monte Carlo simulation and the data are measurements of final state observables in high energy collisions. The complexity of the experiments, the obervables and the models all contribute to making this a highly non-trivial task. We describe an existing library of Fortran routines, HZTool, which enables, for each measurement of interest, a comparable prediction to be produced from any given Monte Carlo generator. The HZTool library is being maintained by CEDAR, with subroutines for various measurements contributed by a number of authors within and outside the CEDAR collaboration. We also describe the outline design and current status of a replacement for HZTool, to be called Rivet (Robust Independent Validation of Experiment and Theory). This will use an object-oriented design, implemented in C++, together with standard interfaces (such as HepMC and AIDA) to make the new framework more flexible and extensible than the Fortran HZTool.Comment: Contribution to CHEP06 conferenc

Expressed sequence tags from the oomycete fish pathogen Saprolegnia parasitica reveal putative virulence factors

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