GROWTH PATTERN, SUSTAINABILITY AND TRADE IN A LAND CONSTRAINED ECONOMY

This paper develops a two-sector model of growth where agriculture is considered explicitly. Key features of the model include: the reliance of agricultural production on a fixed but degrading resource base, the use by the farm sector of industrially produced inputs and differing rates of technological progress in the two sectors. On the demand side, the low income elasticity for food as well as the life-sustaining function of food consumption are recognized. In this simplified framework, the sustainability of growth can be related to the existence of a steady state reflecting the ability of the economy to feed its population. This property is used to identify the characteristics within and outside of agriculture conducive to the sustainability of a land-constrained economy. The empirical application identifies sub-Saharan Africa as the region of the world facing the most important challenges in terms of sustainability. The second part of the paper makes use of the transitional properties of the model to analyse the relationship between agricultural productivity and growth performance. For a closed economy, the model unambiguously supports the view that high agricultural productivity is conducive to fast growth and industrialization. Once the country is allowed to trade, however, the relationship becomes more complex, but a numerical experiment illustrates how trade liberalization can accelerate the growth of a country poorly endowed in agricultural resources.sustainability, agriculture and growth, dynamic general equilibrium model, International Development, O41, O13, F11,

Antisymmetric tensor contribution to the muon g-2

We investigate the Kalb-Ramond antisymmetric tensor field as solution to the muon $g-2$ problem. In particular we calculate the lowest-order Kalb-Ramond contribution to the muon anomalous magnetic moment and find that we can fit the new experimental value for the anomaly by adjusting the coupling without affecting the electron anomalous magnetic moment results.Comment: 7 pages, 1 figur

How Much Do Starting Values Really Matter? An Empirical Comparison of Genetic Algorithm and Traditional Approaches

This research evaluates the impact of using different starting conditions in estimating meat demand systems. Results suggest that as the econometric task becomes increasingly nonlinear, specification of starting conditions becomes increasingly important. This work demonstrates implications of failing to use the best available starting value conditions and how these implications vary with the complexity of the underlying econometric model of interest. Furthermore, this piece proposes a universal approach to be used by all applied econometric practioners to developing appropriate starting values for use in subsequent model estimation.Demand and Price Analysis,

Can the world feed itself? Some insights from growth theory

This paper develops a two-sector growth model incorporating the essential distinguishing features of agriculture, including the reliance of production on a natural resource base as well as on industrially produced inputs, the low income elasticity of demand for food and the life-sustaining function of food consumption. In this framework, the ability of an economy to supply an adequate supply of food to a growing population can be related to the existence of a steady state. This property is used to define a simple analytical criterion upon which to assess the long-term food situation of a closed economy. This sustainability condition relates all the dynamic parameters of the economy: rates of technological change in the two sectors, rate of population growth and rate of land degradation. The condition is used to highlight the technological characteristics in agriculture conducive to sustainability and to assess empirically the food situation of a number of countries. Although no global food crisis appears to be looming ahead, the data suggest that sub-Saharan Africa is likely to increase its food dependence in the future.Food Security and Poverty,

Communications and tracking expert systems study

The original objectives of the study consisted of five broad areas of investigation: criteria and issues for explanation of communication and tracking system anomaly detection, isolation, and recovery; data storage simplification issues for fault detection expert systems; data selection procedures for decision tree pruning and optimization to enhance the abstraction of pertinent information for clear explanation; criteria for establishing levels of explanation suited to needs; and analysis of expert system interaction and modularization. Progress was made in all areas, but to a lesser extent in the criteria for establishing levels of explanation suited to needs. Among the types of expert systems studied were those related to anomaly or fault detection, isolation, and recovery

Economic growth and distribution of income: A growth model to fit Ghanaian data

Income distribution, economic growth, Development strategies,

Mortality from infectious pneumonia in metal workers: a comparison with deaths from asthma in occupations exposed to respiratory sensitizers

Introduction: national analyses of mortality in England and Wales have repeatedly shown excess deaths from pneumonia in welders. During 1979-1990 the excess was attributable largely to deaths from lobar pneumonia and pneumonias other than bronchopneumonia, limited to working-aged men, and apparent in other metal fume-exposed occupations. We assessed findings for 1991-2000 and compared the mortality pattern with that from asthma in occupations exposed to known respiratory sensitizers.Methods: the Office of National Statistics supplied data on deaths by underlying cause among men aged 16-74 years in England and Wales during 1991-2000, including age and last held occupation. We abstracted data on pneumonia for occupations with exposure to metal fume and on asthma for occupations commonly reported to surveillance schemes as at risk of occupational asthma. We estimated expected numbers of deaths by applying age-specific proportions of deaths by cause in the population to the total deaths by age in each occupational group. Observed and expected numbers were compared for each cause of death.Results: among working-aged men in metal fume-exposed occupations we found excesses of mortality from pneumococcal and lobar pneumonia (54 deaths vs. 27.3 expected) and from pneumonias other than bronchopneumonia (71 vs. 52.4), but no excess from these causes at older ages, or from bronchopneumonia at any age. The attributable mortality from metal fume (45.3 excess deaths) compared with an estimated 62.6 deaths from occupational asthma.Conclusion: exposure to metal fume is a material cause of occupational mortality. The hazard deserves far more attention than it presently receive

Visualization of leading edge vortices on a series of flat plate delta wings

A summary of flow visualization data obtained as part of NASA Grant NAG2-258 is presented. During the course of this study, many still and high speed motion pictures were taken of the leading edge vortices on a series of flat plate delta wings at varying angles of attack. The purpose is to present a systematic collection of photographs showing the state of vortices as a function of the angle of attack for the four models tested