Profitability and technical efficiency of aquaculture systems in Pampanga, Philippines

We evaluate the profitability and technical efficiency of aquaculture in the Philippines. Farm-level data are used to compare two production systems corresponding to the intensive monoculture of tilapia in freshwater ponds and the extensive polyculture of shrimps and fish in brackish water ponds. Both activities are very lucrative, with brackish water aquaculture achieving the higher level of profit per farm. Stochastic frontier production functions reveal that technical efficiency is low in brackish water aquaculture, with a mean of 53%, explained primarily by the operator's experience and by the frequency of his visits to the farm. In freshwater aquaculture, the farms achieve a mean efficiency level of 83%. The results suggest that the provision of extension services to brackish water fish farms might be a cost-effective way of increasing production and productivity in that sector. By contrast, technological change will have to be the driving force of future productivity growth in freshwater aquaculture.

Sources of productivity growth in Australian textile and clothing firms

This paper estimates the sources of productivity growth in Australian textile and clothing firms based on the Business Longitudinal Survey (BLS) from 1995 to 1998. Productivity growth estimates have been obtained for each sub-category of textile and clothing firms. Sources of growth in multifactor productivity (MFP) are examined with growth in technical efficiency and scale effects based on estimates of stochastic frontier production functions. Separate estimates of output growth have been compared with the productivity growth estimates for each of the product categories. MFP improved in all clothing firms and declined in textile firms over 1997–1998 by four-digit level of Australia New Zealand Standard Industrial classification Scheme (ANZSIC). MFP declined in most major categories of both textile and clothing firms in 1995–1997. Changes in technical efficiency mostly dominated scale effects in the overall direction of MFPG in both textile and clothing firms. The findings of the study provide evidence for policies for improving the firms' operative performance in the ongoing liberalised regime.

Substitution and complementarity in the creation and communication of Australian university research

The generation of research is one of the major functions of the university sector. In most disciplines, journal articles continue to be the main outlet for the communication of research findings. However, in Australia, government induced distortions have rewarded refereed conference papers an equal status to refereed journal papers. The aim of this paper is to explore the association between research published in journals and research published in conference proceedings. We use a panel dataset of the research output of 36 Australian universities, for the period 1995–2004. Cobb-Douglas research production functions are estimated, as well as a system of research production functions that allows for simultaneity. The results indicate that journals and conferences are contemporaneous substitutes – an expansion in conference publications displaces journal publications. There is also a 'DEST effect'. On average, conference papers are not converted into subsequent journal papers. The DEST effect is found also through analysis of the publication histories of 152 business and law academics. Postgraduate enrolments are shown to contribute only to conferences and have no effect on journal publications. Research income has a positive effect on both conferences and journal publications.

Sources of productivity growth in Australian textile and clothing firms

This paper estimates the sources of productivity growth in Australian textile and clothing firms based on the Business Longitudinal Survey (BLS) from 1995 to 1998. Productivity growth estimates have been obtained for each sub-category of textile and clothing firms. Sources of growth in multifactor productivity (MFP) are examined with growth in technical efficiency and scale effects based on estimates of stochastic frontier production functions. Separate estimates of output growth have been compared with the productivity growth estimates for each of the product categories. MFP improved in all clothing firms and declined in textile firms over 1997–1998 by four-digit level of Australia New Zealand Standard Industrial classification Scheme (ANZSIC). MFP declined in most major categories of both textile and clothing firms in 1995–1997. Changes in technical efficiency mostly dominated scale effects in the overall direction of MFPG in both textile and clothing firms. The findings of the study provide evidence for policies for improving the firms' operative performance in the ongoing liberalised regime.

An agent-based approach to value theory and wealth distribution in economics

Any attempt to model an economy requires foundational assumptions about the relations between prices, values and the distribution of wealth. These assumptions exert a profound influence over the results of any model. Unfortunately, there are few areas in economics as vexed as the theory of value. I argue in this paper that the fundamental problem with past theories of value is that it is simply not possible to model the determination of value, the formation of prices and the distribution of income in a real economy with analytic mathematical models. All such attempts leave out crucial processes or make unrealistic assumptions which significantly affect the results. There have been two primary approaches to the theory of value. The first, associated with classical economists such as Ricardo and Marx were substance theories of value, which view value as a substance inherent in an object and which is conserved in exchange. For Marxists, the value of a commodity derives solely from the value of the labour power used to produce it - and therefore any profit is due to the exploitation of the workers. The labour theory of value has been discredited because of its assumption that labour was the only ‘factor’ that contributed to the creation of value, and because of its fundamentally circular argument. Neoclassical theorists argued that price was identical with value and was determined purely by the interaction of supply and demand. Value then, was completely subjective. Returns to labour (wages) and capital (profits) were determined solely by their marginal contribution to production, so that each factor received its just reward by definition. Problems with the neoclassical approach include assumptions concerning representative agents, perfect competition, perfect and costless information and contract enforcement, complete markets for credit and risk, aggregate production functions and infinite, smooth substitution between factors, distribution according to marginal products, firms always on the production possibility frontier and firms’ pricing decisions, ignoring money and credit, and perfectly rational agents with infinite computational capacity. Two critical areas include firstly, the underappreciated Sonnenschein-Mantel- Debreu results which showed that the foundational assumptions of the Walrasian general-equilibrium model imply arbitrary excess demand functions and therefore arbitrary equilibrium price sets. Secondly, in real economies, there is no equilibrium, only continuous change. Equilibrium is never reached because of constant changes in preferences and tastes; technological and organisational innovations; discoveries of new resources and new markets; inaccurate and evolving expectations of businesses, consumers, governments and speculators; changing demand for credit; the entry and exit of firms; the birth, learning, and death of citizens; changes in laws and government policies; imperfect information; generalized increasing returns to scale; random acts of impulse; weather and climate events; changes in disease patterns, and so on. The problem is not the use of mathematical modelling, but the kind of mathematical modelling used. Agent-based models (ABMs), objectoriented programming and greatly increased computer power however, are opening up a new frontier. Here a dynamic bargaining ABM is outlined as a basis for an alternative theory of value. A large but finite number of heterogeneous commodities and agents with differing degrees of market power are set in a spatial network. Returns to buyers and sellers are decided at each step in the value chain, and in each factor market, through the process of bargaining. Market power and its potential abuse against the poor and vulnerable are fundamental to how the bargaining dynamics play out. Ethics therefore lie at the very heart of economic analysis, the determination of prices and the distribution of wealth. The neoclassicals are right then that price is the enumeration of value at a particular time and place, but wrong to downplay the critical roles of bargaining, power and ethics in determining those same prices.

Um estudo sobre a produtividade total dos fatores em setores de diferentes intensidades tecnólogicas

Este trabalho investigou o problema da determinação da produtividade total dos fatores em diversos setores industriais. Tal determinação se dá por meio de estimação de funções de produção, obtendo-se a produtividade a partir do resíduo destas estimações. A questão que aflora deste procedimento é a existência de correlação entre os resíduos e as variáveis explicativas, implicando em diversos vieses, entre eles o de simultaneidade, de variáveis omitidas e de seleção. Neste trabalho foram abordados diversos métodos de estimação de funções de produção, entre eles os métodos de Olley e Pakes e Levinsohn e Petrin. Todos os métodos foram aplicados a diversos setores da economia. A escolha dos setores se deu com base na intensidade tecnológica de cada um, sendo então escolhidos quatro setores de alta intensidade tecnológica e quatro de baixa intensidade tecnológica. A hipótese básica, fio condutor deste trabalho, é que os diversos métodos de estimação de funções de produção apresentam diferentes resultados quando aplicados a setores de diferentes intensidades tecnológicas. Um dos objetivos deste estudo foi identificar se determinado método seria mais adequado a setores de baixa intensidade tecnológica, enquanto outro seria mais apropriado a setores de alta intensidade tecnológica. Conclui-se que o método de Olley e Pakes é levemente superior ao de Levinsohn e Petrin em ambos os grupos de setores, mas não a ponto de se descartar o segundo método. A sensibilidade dos resultados aos diferentes métodos sugere que todos devem ser consultados. Um resultado adicional deste trabalho é a constatação de que houve queda ou estagnação da produtividade nos setores selecionados para a década de 1996 a 2005.

On the nature of income inequality across nations

In this paper, we investigate the nature of income inequality across nations. First, rather than functional forms or parameter values in calibration exercises that can potentially drives results, we estimate, test, and distinguish between types of aggregate production functions currently used in the growth literature. Next, given our panel-regression estimates, we perform several exercises, such as variance decompositions, simulations and counter-factual analyses. The picture that emerges is one where countries grew in the past for different reasons, which should be an important ingredient in policy design. Although there is not a single-factor explanation for the difference in output per-worker across nations, inequality, followed by distortions to capital accumulations and them by human capital accumulation.

Three essays on education from the perspective of the economics of public setor

This work consists of three essays organized into chapters that seek to answer questions at first sight unrelated, but with one common denominator, which is the scarcity of public resources devoted to education, overall, especially in lower education. . The first chapter deals with the scarcity of resources devoted to education in a context of population aging. Two hypotheses were tested for Brazilian municipalities on the relationship between the aging of the population and educational expenditure. The first, already proven in the literature, is that there is an intergenerational conflict for resources and the increase of the share of elderly in the population reduces the educational expenditure. The second, proposed here for the first time, is that there should be reduction of competition for resources if there is a relationship of co-residence between young and old. The results indicated that an increase in the share of elderly reduces the educational expenditure per youth. But the results also illustrate that an increase in the share of elderly co-residing with youth (family arrangement more common in Latin American countries) raises the educational expenditure, which reflects a reduction of competition for resources between generations. The second chapter assesses the allocative efficiency of investments in Higher Education. Using the difference between first-year and last-year students’ scores from Enade aggregated by HEI as a product in the Stochastic Production Function, is possible to contribute with a new element in the literature aimed at estimating the production function of education. The results show that characteristics of institutions are the variables that best explain the performance of students, and that public institutions are more inefficient than the private ones. Finally, the third chapter presents evidence that the allocation of public resources in early childhood education is important for a better future school performance. In this chapter was calculated the effects of early childhood education on literacy scores of children attending the 2nd grade of elementary school. The results using OLS and propensity score matching show that students who started school at the ages to 5, 4, and 3 years had literacy scores between 12.22 and 19.54 points higher than the scores of those who began school at the ages 6 years or late. The results also suggest that the returns in terms of literacy scores diminish in relation to the number of years of early childhood education.

Desempenho da alface em cultivo orgânico com e sem cobertura morta e diferentes lâminas d'água

O experimento foi conduzido no período de 27/05/2006 a 02/08/2006 no SIPA (Sistema Integrado de Produção Agroecológica), localizado no município de Seropédica-RJ. Nesse trabalho, objetivou-se avaliar o desempenho da cultura da alface (Lactuca sativa L.) cultivada sob diferentes lâminas de irrigação em um solo sem e com cobertura de palhada da leguminosa gliricídia. Foram conduzidos dois experimentos simultâneos, utilizando o delineamento experimental de blocos ao acaso, em ambos os experimentos, nos quais foram aplicadas 5 lâminas de irrigação, correspondendo a 25, 50, 80, 100, 115 % da evapotranspiração da cultura (ETc), sendo a produção final avaliada por meio da determinação da massa fresca, área foliar e número de folhas. Até o nível de 100% ETc, todas as variáveis analisadas tiveram seus valores aumentados, e para o nível de 115%, houve um decrescimento das mesmas. Na produção de massa fresca total, o sistema de cultivo com utilização de cobertura morta foi superior ao sem cobertura não diferenciando estatisticamente ao nível de 5 % probabilidade pelo teste F somente nas lâminas de 25 e 115% ETc.

Secondary protons in the atmosphere at different latitudes

We present a semiempirical method to study the production and propagation of atmospheric secondary protons with energy>100 Mev, moving in the vertical direction. The derived production functions are fitted by the least-square method for the only previously published splash (SP) and return (RE) albedos observed data using the same instrument and measurement sites. The closed agreements between the measurement data and the calculations over a wide range of atmospheric depths lead to a possible extension of the method for other latitudes. The spectra of SP and RE intensities versus the geomagnetic cut-off reveal similar behaviour as assumed earlier by the theory for those components in the Earth's magnetic field. © 1993 Società Italiana di Fisica.

Trade reforms and trade patterns in Latin America

Includes bibliography

Potential output in Latin America: a standard approach for the 1950-2002 period

Includes bibliography

An assessment of the economic impact of climate change on the agriculture sector in Trinidad And Tobago

The economic impact of climate change on root crop, fisheries and vegetable production for Trinidad and Tobago under the A2 and B2 scenarios were modeled, relative to a baseline ―no climate change‖ case, where the mean temperature and rainfall for a base period of 1980 – 2000 was assumed for the years up to 2050. Production functions were used, using ARMA specifications to correct for serial autocorrelation. For the A2 scenarios, rainfall is expected to fall by approximately 10% relative to the baseline case in the 2020s, but is expected to rise thereafter, until by the 2040s rainfall rises slightly above the mean for the baseline case. For the B2 scenario, rainfall rose slightly above the mean for the baseline case in the current decade, but falls steadily thereafter to approximately 15% by the 2040s. Over the same period, temperature is expected to increase by 1.34C and 1.37C under A2 and B2 respectively. It is expected that any further increase in rainfall should have a deleterious effect on root crop production as a whole, since the above mentioned crops represent the majority of the root crops included in the study. Further expected increases in temperature will result in the ambient temperature being very close to the optimal end of the range for most of these crops. By 2050, the value of yield cumulative losses (2008$) for root crops is expected to be approximately 248.8 million USD under the A2 scenario and approximately 239.4 million USD under the B2 scenario. Relative to the 2005 catch for fish, there will be a decrease in catch potential of 10 - 20% by 2050 relative to 2005 catch potentials, other things remaining constant. By 2050 under the A2 and B2 scenarios, losses in real terms were estimated to be 160.2 million USD and 80.1 million USD respectively, at a 1% discount rate. For vegetables, the mean rainfall exceeds the optimal rainfall range for sweet peppers, hot peppers and melongene. However, while the optimal rainfall level for tomatoes is 3000mm/yr, other vegetables such as sweet peppers, hot peppers and ochroes have very low rainfall requirements (as low as 300 mm/yr). Therefore it is expected that any further decrease in rainfall should have a mixed effect on individual vegetable production. It is expected that any further increase in temperature should have a mixed effect on individual vegetable production, though model results indicated that as a group, an increase in temperature should have a positive impact on vegetable production. By 2050, the value of yield cumulative gains (2008$) for vegetables is expected to be approximately 54.9 million USD under the A2 scenario and approximately 49.1 million USD under the B2 scenario, given a 1% discount rate. For root crops, fisheries and vegetables combined, the cumulative loss under A2 is calculated as approximately 352.8 million USD and approximately 270.8 million USD under B2 by 2050. This is equivalent to 1.37% and 1.05% of the 2008 GDP under the A2 and B2 scenarios respectively by 2050. Sea Level Rise (SLR) by 2050 is estimated to be 0.255 m under A2 and 0.215 m under B2. GIS estimation indicated that for a 0.255 m sea level rise, combined with a 0.5 m high tide, there would be no permanent inundation of agricultural land in Trinidad. The total inundation area is 1.18 km2. This occurs only in the Caroni Watershed, on the western coast of Trinidad, and the areas are outside the Caroni Swamp. Even with an additional rise of 0.5 m to simulate a high rainfall event, the estimated inundated area is 4.67 km2, but with no permanent inundation, though likely to be subject to flooding. Based on eleven (11) evaluation criteria, the top potential adaptation options were identified: 1. Use of water saving irrigation systems and water management systems e.g. drip irrigation; 2. Mainstream climate change issues into agricultural management; 3. Repair/maintain existing dams; 4. Alter crop calendar for short-term crops; 5. Adopt improved technologies for soil conservation; 6. Establish systems of food storage; 7. Promote water conservation – install on-farm water harvesting off roof tops; 8. Design and implement holistic water management plans for all competing uses; 9. Build on- farm water storage (ponds and tanks); 10. Agricultural drainage; and 11. Installation of greenhouses. The most attractive adaptation options, based on the Benefit-Cost Ratio are: (1) Build on- farm water storage such as ponds and tanks (2) Mainstreaming climate change issues into agricultural management and (3) Water Harvesting. However, the options with the highest net benefits are, (in order of priority): (1) Build on- farm water storage such as ponds and tanks, (2) Mainstreaming climate change issues into agricultural management and (3) Use of drip irrigation. Based on the area burnt in Trinidad and Tobago between 2005 and 2009, the average annual loss due to fires is 1717.3 ha. At US$17.41 per carbon credit, this implies that for the total land lost to forest fires on average each year, the opportunity cost of carbon credit revenue is 74.3 million USD. If a teak reforestation programme is undertaken in Trinidad and Tobago, the net benefit of reforestation under a carbon credit programme would be 69 million USD cumulatively to 2050.

Desempenho do cultivo da berinjela em plantio direto submetida a diferentes lâminas de irrigação

Este estudo foi conduzido no município de Seropédica, RJ, com o objetivo de se determinar, em cultivo orgânico e sistema de plantio direto, a produtividade da cultura da berinjela sob diferentes lâminas de irrigação e sistemas de cultivo (consorciada com leguminosa e solteira). O delineamento experimental adotado foi o de blocos ao acaso, no esquema de parcela subdividida com quatro repetições caracterizando, na parcela, os tratamentos equivalentes à lâmina de irrigação (40; 70; 100 e 120% ETc) e, na subparcela, os sistemas de cultivo consorciado com feijão caupi e solteiro. Ambos os sistemas de cultivo não influenciaram a produtividade final da berinjela; no entanto, considerando as diferentes lâminas, a maior produtividade comercial foi de 65,41 Mg ha-1, obtida para uma lâmina total de 690,04 mm (106,8% ETc). A menor lâmina aplicada resultou em qualidade inferior dos frutos em relação às maiores lâminas, sendo a taxa de descarte dos frutos de 3 e 14%, respectivamente, para a maior e a menor lâmina.

Factor decomposition of income inequality change : Japan's regional income disparity from 1955 to 1998

We propose a method for the decomposition of inequality changes based on panel data regression. The method is an efficient way to quantify the contributions of variables to changes of the Theil T index while satisfying the property of uniform addition. We illustrate the method using prefectural data from Japan for the period 1955 to 1998. Japan experienced a diminishing of regional income disparity during the years of high economic growth from 1955 to 1973. After estimating production functions using panel data for prefectures in Japan, we apply the new decomposition approach to identify each production factor’s contributions to the changes of per capita income inequality among prefectures. The decomposition results show that total factor productivity (residual) growth, population change (migration), and public capital stock growth contributed to the diminishing of per capita income disparity.