Fragility of Comparative Advantage in Higher Dimensions: An Experimental Investigation

In this study, an experimental analysis of the fragility of the law of the comparative advantage in higher dimensions is performed. Noussair et al (1995) invoked a trading environment similar to the 2 x 2 Competitive Ricardian Model (CRM) and observed the law of comparative advantage. In this experiment, the same experimental setting is invoked however the number of goods and countries is increased. There were three countries and three goods, two countries were categorised as ‘intermediate’ comparative advantage while one as ‘extreme’ comparative advantage. However, the Jones (1961)’s criterion for optimal assignment was satisfied. The experimental findings reveal the following (1) both the autarky model and the competitive model are rejected as a representation of the data but the competitive model performs better than the autarky model (2) the CRM does not predict the production pattern (3) the CRM does not predict pattern of trade (4) output prices do not converge to the prediction of the theoretical model. Thus the results support the claim of Deardoff (2005)

Winners and Losers in Customs Unions: An Experimental Investigation

In the context of a Competitive Ricardian Model (CRM), one can ask whether it is possible to relate winners and losers from a CU based on comparative advantage considerations. This was pursued by Venables (2003), who showed that careful consideration of a country’s comparative advantage – with the rest of the world relative to that with its partners in the CU- yields predictions about winners and losers. Starting from initial tariff equilibrium, in a 3 country model with a continuum of goods, he shows that a country with ‘extreme’ comparative advantage will be more vulnerable to trade diversion. In this experiment, the 3 x 3 Competitive Ricardian Model (CRM) in two scenarios multiple import tariffs and a customs union. We fully characterise the equilibrium under both. Starting from a tariff distorted situation, we find that when a customs union is formed there is an increase in trade flows among members; a rise in individual consumption of some goods; a clear terms of trade effect and the existence of trade diversion. Our experimental results support the simulation findings of Venables (2003), who showed that countries which have ‘extreme’ comparative advantage in a customs union will generally be more vulnerable to trade diversion

Experiments in International Economics

For many decades, economists have lamented the constraints on performing experiments in economics. However, with the birth of experimental economics this perception has changed. This field has developed considerably over the years. Now results from experiments are taken seriously. The experimental literature evolved in three directions: market experiments, game experiments and individual-decision making experiments. Over the years however, experimental methodology has been applied to more complex environments investigating macroeconomic issues and international economics. This paper provides a review of the experimental economics, its ingredients, its promises and skepticism. Further, we provide a review of the experiments that has been carried out in international economics

Stock Market Development And Economic Growth: The Case Of Mauritius

Stock market is an indicator of an economy financial health. It indicates the mood of investors in a country. As such, stock market development is an important ingredient for growth. The stock exchange of Mauritius is fairly new compared to many countries. This paper examines the impact of stock market development on growth in Mauritius. A time series econometric investigation is conducted over the period 1989 -20067. We analyse both the short run and long run relationship by constructing an ECM. Two measures of stock market development namely size and liquidity are used. We define size as the share of market capitalization over GDP and liquidity as volume of share traded over GDP. We found that stock market development positively affect economic growth in Mauritius both in the short run and long run

Production of organic acids, titratable acidity and pH-development during fermentation of cereal flours

ABSTRACT Following the household method of fermentation used in making the Ethiopian bread injera, fermentation of a flour/water slurry was carried out. The fermentation experiments were done at temperatures of 25 and 35 °C with whole grain wheat flour, whole grain tef (Eragrostis tef) flour and commercial bakery flour of 70% extraction rate. The slurry was made by mixing 300 g flour and 600 ml water. Backslopping was done by adding a portion of the slurry which was fermented in a previous batch as a starter (0.1%, 1.0%, and 10%) to the next batch to be fermented. During the fermentation, samples were taken at definite intervals of 3, 6, 9, 12, 18, 24, 48 and 84 hours respectively and kept frozen until they were used for analysis. The pH and titratable acidity were recorded and the organic acids were determined by HPLC using an Aminex® HPX-87H column, The growth of lactic acid bacteria including the typing of species/strains was also determined. Samples of the fermenting slurry were taken for analysis and the final concentration of lactic acid was found to be approximately 1 g per 100 g. A higher amount of inoculum gave a quicker lowering of pH, and also a lower initial pH. A smaller inoculum amount showed a delayed start in the lowering of pH. A higher temperature increased the production rate of lactic acid. The dominant (100% at 25°C) species of the final sample of fermented tef slurry was found to be Lactobacillus plantarum. Commercial bakery flour showed a comparatively low buffering capacity, less than 0,1 g lactic acid/100 g was needed to reduce pH to <5. Tef, a cereal with very small seeds contributing a larger portion of outer parts of the seeds in the flour, had the highest buffering capacity. In the region pH 6 to 4, approximately double the amount of lactic acid was required in comparison to the commercial bakery flour in order to attain the same pH. This indicates that at the same pHlevel, a fermented food item made of tef, and also of whole grain wheat, probably has a higher food safety than a food item made of commercial bakery flour. Thus, the use of whole grain flour improves not only the nutritional quality, but also the food safety of a fermented food, which is of importance under household conditions of low-income countries. At normal injera fermentation (tef, 1% backslopping at 25°C) it took 12 h t

Long-Short Term Memory for an Effective Short-Term Weather Forecasting Model Using Surface Weather Data

Part 7: Deep Learning - Convolutional ANNInternational audienceNumerical Weather Prediction (NWP) requires considerable computer power to solve complex mathematical equations to obtain a forecast based on current weather conditions. In this article, we propose a lightweight data-driven weather forecasting model by exploring state-of-the-art deep learning techniques based on Artificial Neural Network (ANN). Weather information is captured by time-series data and thus, we explore the latest Long Short-Term Memory (LSTM) layered model, which is a specialised form of Recurrent Neural Network (RNN) for weather prediction. The aim of this research is to develop and evaluate a short-term weather forecasting model using the LSTM and evaluate the accuracy compared to the well-established Weather Research and Forecasting (WRF) NWP model. The proposed deep model consists of stacked LSTM layers that uses surface weather parameters over a given period of time for weather forecasting. The model is experimented with different number of LSTM layers, optimisers, and learning rates and optimised for effective short-term weather predictions. Our experiment shows that the proposed lightweight model produces better results compared to the well-known and complex WRF model, demonstrating its potential for efficient and accurate short-term weather forecasting

Insecticide resistance and the future of malaria control in Zambia.

BACKGROUND: In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission. METHODS: Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years. RESULTS: A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period. CONCLUSION: Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme

Investigations into air and refrigerant side heat transfer coefficients of finned-tube CO2 gas coolers

Gas coolers are heat rejection heat exchangers in vapour compression refrigeration systems that use carbon dioxide (CO2) as refrigerant. The design of gas coolers has a significant influence on the performance of CO2 refrigeration systems as it determines to a large extent the gas cooler/condenser pressure and the power consumption of the system. This paper investigates local refrigerant and air heat transfer coefficients in plain fin-and-tube gas cooler coils using Computational Fluid Dynamics (CFD) modelling. The aims were to provide insights into the variation of the local heat transfer rates in the coil and determine the influence of a) design enhancements such as the use of slit fins and b) to develop correlations for overall refrigerant and air heat transfer coefficients to be used in CO2 refrigeration component and system modelling. The results from the model which was validated against experimental measurements showed that a horizontal slit on the fin between the first and second row of tubes can lead to an increase in the heat rejection rate of the gas cooler by between 6% and 8%. This in turn can lead to smaller heat exchanger heat transfer area for a given heat rejection capacity or lower high side pressure and higher efficiency for the refrigeration system. The results and heat transfer correlations developed are a valuable resource for researchers and manufacturers of CO2 and other heat exchanger coils that experience a wide variation in refrigerant temperature during the gas cooling process.This study was supported by the RCUK National Centre for Sustainable Energy use in Food chains (CSEF) of the Research CouncilsUK Energy programme, Grant No: EP/K011820/1, GEA Searle, now Kevlion, and Directorate General for Higher Education-DIKTI–Indonesian Government for a PhD scholarship