Determining decay rates of polar cap plasma using bservations of polar cap patches

Polar cap patches are large scale structures occurring in the high-latitude ionosphere. They are regions of enhanced plasma density of at least twice the background density, and they are often observed in the polar cap region. The primary decay mechanism is via a two-step rearrangement and recombination reaction involving Oxygen and Nitrogen. Small scale structures within polar cap patches can result in scintillation of radio signals such as those used in Global Navigation Satellite Systems (GNSS). As such, quantifying the decay rate of the plasma is of importance if the effects on such communications are to be predicted. Observations were obtained during the Northern Deep Winter experiment, a series of incoherent scatter radar world days that took place in December 2014. Data from multiple incoherent scatter radars at high latitudes will be utilised to observe the same plasma at several locations as it is transported. From these observations, the decay of the plasma will be calculated and compared to the results of laboratory experiments

The Determinants of Financial Derivatives Use in the UK life Insurance Industry

This paper examines the determinants of financial derivatives use in the United Kingdom (UK) life insurance industry. We estimate a probit regression model and a Heckman two-stage sample selection regression model using a sample of 88 UK life insurers in 1995. Our results indicate that the propensity to use derivative instruments is positively related to a firm’s size, leverage and international links, and negatively related to the extent of reinsurance. We also find that mutual life insurance firms have a greater propensity to use derivatives than proprietary firms. The positive relation with leverage and the negative relation with reinsurance support the hypothesis that UK life insurers use derivatives to offset risk, rather than as a speculative means of income generation

Soil Fertility Management And Maize Productivity In Malawi: Curvature Correct Efficiency Modeling And Simulation

We assess the level and determinants of relative technical efficiency of maize-based smallholder farmers using a translog stochastic frontier (TL) model and a symmetric generalized Barnett production function (SGB), both of which are tested for economic regularity conditions. In addition, we conduct a bootstrapping procedure in order to infer about the probability distributions and significance of the relative efficiency values for farmers using different soil fertility management options. The results indicate that higher levels of relative technical efficiency obtain when farmers use integrated soil fertility options compared to the use of chemical fertilizer only. The consistency of the results across the two models increase the robustness of the findings. The paper concludes that productivity growth under the maize-based farming systems is considerably higher when farmers use integrated soil fertility management options. Thus there is need for policy and institutional interventions that enhance farmers’ adoption and scaling-up of integrated soil fertility management.Smallholder agriculture, relative technical efficiency, soil fertility management, Malawi, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, International Relations/Trade, Labor and Human Capital, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

The Determinants of Credit Ratings in the United Kingdom Insurance Industry

Executive Summary The Determinants of Credit Ratings in the United Kingdom Insurance Industry Academic researchers have devoted a considerable amount of attention to the activities of credit rating agencies over the past 20 years, focusing in particular on the agencies’ potential role in overseeing corporate financial strength and promoting the efficient operation of financial markets. Examinations of credit rating practices has recently extended to the insurance industry, where the complex technical nature of market transactions leads to policyholders, investors and others facing particularly acute information asymmetries at the point-of-sale. Published credit ratings are therefore seen as helping to alleviate imperfections in insurance markets by providing a third party opinion on the adequacy of an insurer’s financial health and the likelihood of it meeting obligations to policyholders and others in the future. Although the United Kingdom (UK) insurance market is now one of the five largest in the world, relatively little is known about the practices of the major firms and policy-makers which influence its operations. In particular, whilst the determinants of rating agencies’ assessments of United States (US) insurers is well documented, published studies have yet to provide comprehensive evidence about insurance company ratings in the UK. This study attempts to fill this gap by examining the ratings awarded by two of the world’s leading agencies – A.M. Best and Standard and Poor (S&P) – and establishing the extent to which organizational variables can help predict: (i) insurance firms’ decision to be rated; and (ii) the assigned ratings themselves. Our sample of UK data comprises ratings made by A.M. Best and S&P over the period 1993-1997 for both life and property-liability insurers. The panel data we use is ordinal in nature and is therefore analysed using an ordered probit model. However, because neither A.M. Best or S&P rate the full population of UK insurance firms our data set is potentially subject to selfselection bias and we therefore extend the model to correct for such problems. In particular, the paper examines the effect of eight firm-specific variables (namely, capital adequacy, profitability, liquidity, growth, size, mutual/stockowner status, reinsurance level, and short/long-term nature of business) on the ratings awarded by the two agencies, as well as on insurance firms’ decisions to volunteer for the ratings in the first place. In general terms, our evidence concurs with earlier US findings, and suggests that although the decision to be rated by either of the agencies is largely influenced by a common set of factors, the determinants of the ratings themselves appear to differ. Specifically, our first main finding is that insurers’ decisions to be rated by either A.M. Best or S&P is positively related to surplus growth, profitability and leverage. Second, while we find that A.M. Best’s ratings are positively linked to profitability and liquidity, as well as being generally higher for mutual insurers, the findings for S&P differ substantially. Although liquidity again exerted a positive influence on assigned ratings, the only other statistically significant variable was financial leverage, which had a negative sign. We believe that the results of our research are of potential importance for companies operating in insurance markets as well as for policy-makers, brokers and others. For example, the evidence that mutual insurers are generally assigned higher ratings than stock insurers suggests that certain publicly-traded insurers, in particular new entrants, might not possess sound financial strength and may require closer regulatory scrutiny than other, more established, insurance firms. In addition, the finding that liquidity has a significantly positive effect on ratings assigned by two of the world’s leading credit agencies should provide a measure of confidence about the robustness of the ratings to industry regulators, policyholders and investors in the UK. This could imply that external ratings might eventually play a role in substituting for costly industry regulation. The study concludes that although the factors influencing the decision to be rated by A.M. Best or S&P are broadly the same, a degree of variability exists in the variables which influence the actual ratings themselves. Insurance company managers should be aware of this when contemplating whether to seek an independent rating and which agency to choose for the assessment. We therefore believe that this study fills an important gap in the literature about key players in the important UK insurance market and provides a basis for the conduct of future research

Quantitative value chain analysis : an application to Malawi

The Government of Malawi has since 2005 been pursuing a growth strategy mainly based on increasing the volume of agricultural exports. This entails that Malawi should endeavor to improve the competitiveness of its agricultural commodities so as to gain an increasing share of the regional and international markets. This paper analyzes the competitiveness of the country's key agricultural commodities -- tobacco, maize, cotton, and rice -- using prices that prevailed in the 2007/08 agricultural season. The paper employs a quantitative value chain methodology to assess the country's prospects for competitiveness and suggest weak links along the value chain that require attention in order to improve trade competitiveness. The results indicate that Malawi has some competitive advantage in the production and exportation of tobacco and cotton, and that this mostly derives from its low labor cost advantage. However, the results indicate that based on 2007/08 prices and costs, Malawi does not have competitive edge in maize and rice production for export. As such, Malawi would better pursue an import substitution strategy in these cereals, and perhaps only aim at the export market when regional market opportunities arise. Key factors that underpin Malawi's narrow competitiveness include the high cost of inorganic fertilizer and other inputs, low productivity, and the higher trader margins and intermediation costs along the value chains. Furthermore, farm gate prices in Malawi are higher than in other countries, and this undercuts its trade competitiveness.Transport Economics Policy&Planning,Crops&Crop Management Systems,Economic Theory&Research,Markets and Market Access,Climate Change and Agriculture

Alternative Soil Fertility Management Options in Malawi An Economic Analysis

In this paper, we analyze the factors that influence t he productivity of maize among smallholder farmers, given that unfavourable output and input market conditions throughout the 1990s have compelled smallholder farmers into unsustainable agricultural intensification. We use farm-household survey data in order to compare the productivity of smallholder maize production under integrated (ISFM) and chemicalbased soil fertility management using a normalized translog yield response model. The results indicate higher maize yield responses for integrated soil fertility management options after controlling for the intensity of fertilizer application, labour intensity, seed rate as well as land husbandry practices a s well as selected policy factors. The estimated model is highly consistent with theoretical conditions. Thus we conclude that the use of ISFM improves maize productivity, compared to the use of inorganic fertilizer only. Since most farmers in the maize-based farming systems are crowded out of the agricultural input market and can hardly afford optimal quantities of inorganic fertilizer, enhancement of ISFM is likely to increase their maize productivity. We finally highlight areas of policy support needed to enhance ISFM uptake in smallholder maize-based farming systems.smallholder agriculture, yield response model, soil fertility management, Malawi, Land Economics/Use,

SOIL FERTILITY MANAGEMENT AND AGRICULTURAL PRODUCTIVITY IN MALAWI

In this paper we analyze the factors that influence the productivity of maize among smallholder farmers. We use farm-household survey data in order to compare the productivity of smallholder maize production under integrated (ISFM) and chemical-based soil fertility management using a normalized translog yield response model. The results indicate higher maize yield responses for integrated soil fertility management options after controlling for the intensity of fertilizer application, labour intensity, seed rate, land husbandry practices as well as selected policy factors. The estimated model is highly consistent with theoretical conditions. Thus we conclude that the use of ISFM improves maize productivity, compared to the use of inorganic fertilizer only. Since most farmers in the maize-based farming systems are crowded out of the agricultural input market and can hardly afford optimal quantities of inorganic fertilizer, enhancement of ISFM is likely to increase their maize productivity. We finally highlight areas of policy support needed to enhance ISFM uptake in smallholder maize-based farming systems.Malawi, smallholder agriculture, soil fertility management, yield response model, Farm Management,

GERM as a tool for space station documentation

GERM as a tool for space station documentation is presented in the form of viewgraphs. The following subject areas are covered: problem statement, hypermedia as a tool for documentation, description of GERM, technical approach, application development, and results and conclusions

Alternative Soil Fertility Management Options in Malawi - An Economic Analysis

In this paper, we analyze the factors that influence the productivity of maize among smallholder farmers, given that unfavourable output and input market conditions throughout the 1990s have compelled smallholder farmers into unsustainable agricultural intensification. We use farm-household survey data in order to compare the productivity of smallholder maize production under integrated (ISFM) and chemical-based soil fertility management using a normalized translog yield response model. The results indicate higher maize yield responses for integrated soil fertility management options after controlling for the intensity of fertilizer application, labour intensity, seed rate, land husbandry practices as well as selected policy factors. The estimated model is highly consistent with theoretical conditions. Thus we conclude that the use of ISFM improves maize productivity, compared to the use of inorganic fertilizer only. Since most farmers in the maize-based farming systems are crowded out of the agricultural input market and can hardly afford optimal quantities of inorganic fertilizer, enhancement of ISFM is likely to increase their maize productivity. We finally highlight areas of policy support needed to enhance ISFM uptake in smallholder maize-based farming systems.Malawi, smallholder agriculture, soil fertility management, yield response model, Livestock Production/Industries,

The efficiency of maize farming in Malawi. A bootstrapped translog frontier

We measure the level and determinants of technical efficiency of maize based smallholder farmers using a bootstrapped translog stochastic frontier that is a posteriori checked for functional consistency. The results show that higher levels of technical efficiency are obtained when farmers use integrated soil fertility options compared to the use of inorganic fertilizer only. With respect to the policy variables considered in the analysis, access to agricultural input and output markets, credit provision and extension services strongly influence smallholders’ technical efficiency. There is a need to strengthen these public policy issues in order to effectively address the efficiency of Malawian agriculture and its impact on poverty by ensuring sustainable soil fertility management.smallholder agriculture, bootstrapped frontier, soil fertility management, Malawi