Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / SÃo estimadas as eficiÃncias tÃcnicas de 36 firmas de distribuiÃÃo de energia elÃtrica. Para tanto, quatro mÃtodos sÃo adotados: um paramÃtrico e trÃs nÃo paramÃtricos. No mÃtodo paramÃtrico, a AnÃlise de Fronteira EstocÃtica (SFA), utilizou-se uma funÃÃo de produÃÃo do tipo Cobb-Douglas. O Data Envelopment Analysis (DEA), o Free Disposal Hull (FDH) e o mÃtodo de Martins-Filho e Yao (2004) sÃo os trÃs mÃtodos nÃo paramÃtricos adotados. Concluiu-se que, o conjunto de produÃÃo nÃo segue rendimentos crescentes de escala. Observou-se que, as firmas do Sudeste foram mais eficientes em mÃdia, que as demais. O mÃtodo de Martins-Filho e Yao (2004) Ã o mais adequado, pois requer um nÃmero menor de hipÃteses e tem a caracterÃstica de ser um estimador suave. / The technical efficiency is estimated for 36 energy distribution firms. Four methods were adopted: one parametric and three nonparametric. In the parametric method, the Stochastic Frontier Analysis (SFA), the Cobb-Douglas production function was used. The Data Envelopment Analysis (DEA), the Free Disposal Hull (FDH) and the method developed by Martins-Filho and Yao (2004) are the three nonparametric methods adopted. It was seen that, the production set didnât follow increasing returns to scale. It was concluded that, the firms of the Southeast region of Brazil were, on the average, more efficient than the others. The Martins-Filho and Yaoâs (2004) method was most the adequate, since it requires less assumptions and has the characteristic of being a smooth estimator.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Para sucesso da exploraÃÃo agrÃcola à necessÃrio incrementar tÃcnicas de cultivo e manejo da cultura do cajueiro para que assegure uma produÃÃo eficiente e de qualidade. O uso da funÃÃo de produÃÃo permite a obtenÃÃo de planos Ãtimos de cultivo com base nos nÃveis de Ãgua e adubo. Baseado nessas premissas, esse trabalho teve como objetivo obter e analisar sob o aspecto econÃmico a resposta do clone do cajueiro anÃo precoce BRS 189 aos fatores de produÃÃo Ãgua e adubo potÃssico. O experimento foi conduzido no nÃcleo D do PerÃmetro Irrigado Curu â Pentecoste, CearÃ, de junho a dezembro de 2009. O delineamento experimental foi de blocos ao acaso no esquema de parcelas subdivididas, composto de quatro tratamentos primÃrios nas parcelas e quatro tratamentos secundÃrios nas subparcelas. Os tratamentos primÃrios corresponderam a 25, 50 100 e 200% da lÃmina evapotranspirada da cultura, estimada atravÃs do tanque classe A, e os tratamentos secundÃrios referentes Ãs doses de K2O 0, 50, 100 e 200 g planta-1ano-1. O pomar de cajueiro foi instalado em 2005 sendo essa pesquisa realizada no quarto ano, Ãpoca em que a cultura atinge seu potencial de produÃÃo. O clone utilizado foi espaÃado de 7,0 m x 7,0 m irrigado por um sistema de irrigaÃÃo por microaspersÃo. As anÃlises constaram em duas etapas: CaracterÃsticas pÃs-colheita (sÃlidos solÃveis totais - SST, peso mÃdio, comprimento mÃdio e diÃmetro mÃdio do pedÃnculo) e anÃlise quantitativa (produtividade do pedÃnculo e castanha). Os resultados permitiram as seguintes conclusÃes: O fator de produÃÃo potÃssio apresentou influÃncia significativa em nÃvel de 5% para os caracteres pÃs-colheita do caju. Com exceÃÃo da variÃvel peso mÃdio do fruto que apresentou influÃncia significativa em nÃvel de 1% para o fator de produÃÃo Ãgua. A mÃxima produtividade fÃsica observada, de 6.665,7 kg ha-1 foi obtida com o tratamento W3K3, referente a 100% da evapotranspiraÃÃo mÃxima da cultura e 200 g planta-1ano-1 de K2O ou 40,8 kg ha-1ano-1. A produtividade mÃxima estimada (7.600,9 kg ha-1) correspondeu a uma necessidade de Ãgua superior em 14,5% ao tratamento W3 (100% de ETc) e 140,5 g planta-1 ano-1 de K2O, valor este igual ao recomendado pela anÃlise de solo. O nÃvel de Ãgua economicamente Ãtimo està 4,5% abaixo do nÃvel de Ãgua observado que proporcionou a mÃxima produtividade. Jà a produtividade econÃmica à inferior em apenas 1,4% à produtividade estimada pelo modelo estatÃstico, e proporciona uma economia de Ãgua de 15,5% comparativamente ao nÃvel de Ãgua estimado pelo modelo para mÃxima produtividade fÃsica. / For the success of the cashew culture as an agrarian enterprise, it is necessary to enhance farming techniques and crop management of cashew, ensuring efficient production and quality. The use of the production function allows the cashew grower to conceive optimal cultivation plans based on optimal levels of watering and fertilizing. Based on these considerations, this study was aimed at determining and analyzing the response of the dwarf cashew clone BRS 189 to the production factors water and potassium fertilizer, particularly from an economic viewpoint. The experiment was conducted in the D core of the PerÃmetro Irrigado (irrigated perimeter) Curu - Pentecoste (Ce), in the period from June to December 2009. The experimental design was randomized blocks with split plots consisting of four primary treatments in plots and four secondary treatments in subplots. Initial treatment consisted of 25, 50, 100 and 200% of the water volume lost by evapotranspiration by the culture, as estimated by a class A tank, and the secondary treatments consisted of applications of 0,50,100 and 200 g tree-1 year-1 of K2O. The cashew orchard was established in 2005 and this survey was done in the fourth year, a time when this culture reaches its full production potential. The clone used spaced 7.0m x 7.0m, irrigated by a micro-sprinkler irrigation system. Analysis consisted of two stages: post-harvest characteristics (TSS, average fruit weight, average length and diameter) and quantitative analysis (productivity). The results obtained led to the following conclusions: The potassium production factor had significant influence at the level of 8%, for the analyzed cashew post-harvest production variables. For the water production factor, however, only the variable average fruit weight showed significant influence, at the level of 5%. The maximum observed physical productivity, of 6665.7 kg ha-1, was obtained with treatment W3K2, referring to the watering equivalent to 100% of maximum crop evapotranspiration and an application of 100 g K2O-1 tree-1year-1 or 20.4 kg ha-1year-1. The estimated maximum yield (7600.9 kg ha-1) corresponded to an water requirement of more than 14.5% of the treatment W3 (100% ETm) and 140.5 g tree-1 year-1 of K2O, an amount equal to that recommended by soil analysis. The economically optimal watering level is 4.5% below the watering level observed to provide the highest productivity. Now, the economic productivity is only 1.4% lower than the productivity estimated by the statistical model, and saves 15.5% water, when compared with the watering requirements estimated by the physical model for maximum productivity.

A avaliação do estado nutricional das culturas requer o uso de padrões para comparação, tais como os níveis críticos e as faixas de suficiência. Esses padrões de interesse agrícola geralmente são estimados a partir da curva de calibração da produção vegetal, que relaciona os rendimentos de uma cultura com a dose do adubo aplicada no solo ou com o teor de algum elemento nos tecidos. A curva de produção vegetal é fundamental para o desenvolvimento de pesquisas nas áreas de nutrição mineral de plantas e adubação, uma vez que o conhecimento a seu respeito possibilita o uso econômico de adubos e a elaboração de estratégias corretivas para o solo. No entanto, a curva de produção divide-se em diferentes regimes nutricionais, que lhe conferem uma forma peculiar e dificultam sua descrição matemática. O objetivo desse trabalho é a construção de modelos de regressão flexíveis, capazes de descrever adequadamente a curva de produção vegetal. Em uma primeira abordagem, modelos lineares segmentados com transições de fase suaves são usados para descrever a produção do trigo de inverno em função da adubação com nitrogênio. Por meio dos ajustes destes modelos, também são estimados os níveis críticos e as faixas de suficiência. Posteriormente, realiza-se a modelagem matemática da resposta vegetativa à adubação, desconsiderando doses tóxicas. Observa-se que cada tipo possível de resposta vegetativa é ligado de forma unívoca a uma função de produção agrícola. A técnica proposta, além de permitir a construção de novas funções de produção, fornece interpretações fisiológicas claras para parâmetros de alguns modelos de uso comum na agricultura. Com base na segunda abordagem, um novo enunciado para a lei de Mitscherlich é apresentado: quanto maior é o conteúdo total do nutriente limitante na planta, menor é o aproveitamento feito (a fim de lhe prover crescimento) de um incremento em sua disponibilidade - como consequência, os retornos da adubação são decrescentes. / The evaluation of the plant nutritional status requires standards for comparisons, such as the critical levels and sufficiency ranges. These standards are generally estimated by means of the yield curves in response to fertilizers, which relates production with doses applied or nutrient content in the plant tissues. The yield curve is essential for the development of researches on plant mineral nutrition and fertilization, since knowledge of this curve allows economic use of fertilizers and planning strategies for soil correction. However, the production curve is divided into different nutritional regimes, which give it a peculiar shape and hinders its mathematical description. In this work, the objective is to build flexible regression models, able to adequately describe the yield curves. In a first approach, linear piecewise models with smooth transitions between regimes are used to describe the winter-wheat yield in function of the nitrogen doses. By means of the fits of these models, the critical levels and sufficiency ranges are also estimated. In another approach, it is proposed a mathematical model for yield response (or returns) from fertilizers - toxic doses are neglected in this phase. It is verified that each possible yield response type is uniquely related with a production function. This approach allows to construct new production functions and, indeed, provides clear physiological interpretations for the parameters of some common models in agriculture. Based on the second approach, it is presented a new statement for the Mitscherlich law: the greater is the total content of the limiting nutrient in the plant, the lower is the exploited fraction (in order to provide growth) of an increment in its availability - as a consequence, the returns from fertilization are diminishing.

The selection of a suitable model for efficiency analysis is one of the most important issues in policy analysis. Given the recent interest in the use of distance functions as alternative representation of production technology, this study compares the empirical performances of the parametric stochastic input distance function to its nonparametric counterpart, data envelopment analysis. A further comparison is made between the alternatives of a distance and production function frontiers. It further integrates efficiency scores from the consistent approaches in order to evaluate the performance of the sampled farm households and for analysis of policy impacts on technical, allocative and cost efficiency. The usefulness of the proposed methodology is applied to smallholder maize production in Benue State Nigeria. The maize subsector has featured in a number of Nigeria’s policy initiatives, the most current of which involves doubling of its production and productivity through promotion of improved technologies such as hybrid seed, inorganic fertilizer, pesticides, herbicides, and better management practices. Despite the policy initiatives, maize productivity has remained low raising questions about the efficiency of resource use by farmers and the benefits of Nigeria’s technology policy. The study used data obtained from a field survey for the 2008/2009 agricultural year. A multistage stratified sampling technique was employed in selection of respondents. A total of 240 maize farm households were randomly selected and interviewed using structured questionnaires. Results from all the approaches indicated considerable technical, allocative and cost inefficiency under both traditional and improved maize technology. Technical efficiency estimates range from 80 to 87 percent. Allocative efficiency estimates range from 53 to 74 percent while cost efficiency estimates range from 45 to 62 percent. The results from all the approaches indicated that inefficiency in maize production in Benue State is dominated by cost inefficiency suggesting the immense potential of enhancing production through improvement in overall efficiency. The overall consistency check shows that technical, allocative and cost efficiency measures from the three distance functions were consistent whereas similar conclusions could not hold when these were compared to the production frontier especially for technical efficiency estimates. Given the consistency of results from the parametric and non-parametric distance functions, an integrated input distance model was developed for providing final efficiency estimates and analysis of policy impacts. The results show that both traditional and improved technology users were technically, allocatively and cost inefficient. The average technical, allocative and cost efficiency are 84.2, 65.7 and 54.5 percent, respectively implying that there is a possibility of raising maize production by 45.5 percent through overall efficiency improvement. Under the integrated approach, the study revealed that hybrid seeds, inorganic fertilizer and conservation practices have positive and significant impact on farm efficiency. Other determinants of efficiency include education, age, household size, land size, credit, and membership in a farmer group. The findings justify the need for further public investment in maize technology development and proper implementation of the relevant policies in order to enhance the efficiency with which maize has been produced thereby increasing its productivity, food security and farm incomes and subsequently reducing poverty in Nigeria. / Thesis (PhD)--University of Pretoria, 2011. / Agricultural Economics, Extension and Rural Development / unrestricted

This dissertation is attempting to estimate the effects of infrastructure on the economic performance in the sample of European countries. I created two models which try to estimate different impacts of infrastructure on the economy. First of them is based on the Cobb-Douglas production function which estimates the direct effect. Second, is the model based on the Holtz-Eakin and Schwartz approach which measures the spatial spillovereffect.

Public school per pupil costs and demands for better performance have increased over the past several decades. While the overall per pupil expenditures have increased, the percent of the educational dollar directed toward instructional activities has remained at approximately 60%. A grass-roots movement known as the "65% Solution" caught national attention by claiming that schools are not efficiently allocating resources into areas that have the greatest link to student achievement, such as instruction. Proponents of the 65% Solution claim that per pupil expenditures can be increased by shifting funds from areas considered non-instructional to areas that directly impact student instruction, such as teachers and instructional materials. The purpose of this study was to determine the relationship between district Panel Recommended and Commended Performance TAKS Reading/ELA and Math results and three measurements of instructional expenditures, Instructional Staff Percent; TEA Instructional Expenditure Ratio; and the NCES Instructional Expenditure Ratio (65% Solution), in Texas public schools. Data was collected from the 2003-2004 AEIS report. Multiple regression was used to conduct the analyses. In most instances, there was little, if any, relationship between TAKS Reading/ELA and TAKS Math, and the Instructional Staff Percent (ISP), TEA Instructional Expenditure Ratio (TIER), and NCES Instructional Expenditure Ratio (NIER). However, a low to moderate relationship was discovered in the comparison of TAKS Reading/ELA, and the ISP and TIER. This result was the same for both the Panel Recommended and Commended Performance. In every instance, the ISP and TIER showed positive, statistically significant, relationships to TAKS results. The NIER, or 65% Solution, had the lowest correlation and was statistically insignificant in three out of four analyses.

Smallholder farmers' efficiency has been measured by different scholars using different approaches. Both parametric and non-parametric approaches have been applied; each presenting unique results in some ways. The parametric approach uses econometric approaches to make assumptions about the error terms in the data generation process and also impose functional forms on the production functions. The nonparametric approaches neither impose any functional form nor make assumptions about the error terms. The bottom line of both approaches is to determine efficiency in production. In this study a parametric stochastic frontier approach is used to assess technical, allocative and economic efficiency from a sample of smallholder maize producers of Chongwe District, Zambia. This approach was chosen based on the fact that production among this group of farmers varies a great deal, and so the stochastic frontier attributes part of the variations to the random errors (which reflects measurement errors and statistical noise) and farm specific efficiency. Using a Cobb-Douglas frontier production function which exhibits self dual characteristics, technical efficiency scores for the sample of the smallholder maize producers are derived. With the parameter estimates(âi) obtained from the Cobb-Douglas stochastic production frontier, input prices (âi) and taking advantage of the self dual characteristics of the Cobb-Douglas, a cost function is derived. This forms the basis for calculating the farmers' allocative and economic efficiency. Results obtained from the study showed considerable technical, allocative and economic inefficiencies among smallholder maize producers. Technical Efficiency (TE) estimates range from 40.6 percent to 96.53 percent with a mean efficiency of 78.19 percent, while Allocative Efficiency (AE) estimates range from 33.57 to 92.14 percent with a mean of 61.81. The mean Economic Efficiency (EE) is 47.88 percent, with a minimum being 30 percent and a maximum of 79.26 percent. The results therefore indicate that inefficiency in maize production in Chongwe District is dominated by allocative and economic inefficiency. Additionally, in the two stage regression households characteristics: age; sex; education level; occupation; years in farming; land ownership; household size; access to extension and access to credit services; are regressed against technical efficiency scores using a logit function. Results obtained shows that land ownership, access to credit services, access to extension services, land ownership and education level of up to post primary (secondary and tertiary) have a positive influence on the households' technical efficiency. On the other hand, age of the household head; female headed household and lack of education (though not statistically significant at any confidence level) have a negative influence on this group of maize producers. In a similar two stage regression, access to extension services, membership to producer organisation, access to credit and disaster experienced on the farm such as floods, drought and hail, are regressed against AE. The result shows that access to extension services, access to credit services, membership to cooperatives and natural calamities affect AE. Results therefore show that there is a great deal of both allocative and economic inefficiency among smallholder maize farmers than there is technical inefficiency. To address these inefficiencies observed there is need to design policies that will ensure that environmental (e.g. poor land practices which lead to nutrient depletion from the soils), economic (e.g. high transport cost due to poor road infrastructure) and institutional issues (access to credit) are addressed. In other words, Government should help create credit facilities to provide affordable loans to this group of farmers. Additionally, there is need to improve extension systems to help educate farmers about better farming practices and other innovative technologies to further improve their efficiency in production. Issues of land ownership among this group of farmers needs to be addressed as this will not only raise confidence but will also ensure that their cost of production is reduced since there will be no need for payment of rental charges, and that farmers will adhere to good farming practices knowing they own title to land. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Agricultural Economics, Extension and Rural Development / unrestricted

A presente pesquisa teve como objetivo avaliar a política de desoneração da folha de pagamentos da indústria de transformação por meio de uma abordagem metodológica alternativa e complementar ao método de diferenças em diferenças, que é usualmente utilizado em tais casos. Este tema é relevante na medida em que a perda de dinamismo do setor industrial brasileiro tem feito ressurgir o debate a respeito da hipótese de desindustrialização. Ainda que a ocorrência ou não deste fenômeno não seja consensual, este cenário levou o governo a retomar o uso de políticas industriais desde 2004, sendo a desoneração da folha de pagamentos uma das medidas mais relevantes tomadas recentemente para promover a recuperação do setor industrial. A medida ambiciona reduzir os custos trabalhistas para impulsionar o emprego e a produção do setor, além de melhorar sua competitividade, e se destaca pela grande quantidade de recursos empregada: entre 2011 e 2013 a renúncia fiscal associada à pollítica foi de R$ 20 bilhões. Para avaliar esta medida, a presente pesquisa considerou a tributação sobre a mão de obra como uma fonte de imperfeição no mercado de trabalho, a qual é estimada por meio da metodologia proposta por Petrin e Sivadasan (2013). Ao considerar que a política reduz tais imperfeições, foi possível estimar seu efeito no nível de emprego da indústria por meio de extensões ao modelo proposto pelos autores. Foram utilizados microdados da Pesquisa Industrial Anual (PIA-Empresa) em nível de firma entre os anos de 1996 e 2011. A variação no emprego das indústrias beneficiadas pela medida foi de apenas 0,84%, considerando somente as indústrias inicialmente beneficiadas pela política. Os efeitos da política aumentaram com sua expansão, o que ocorreu não somente como consequência do aumento no número de indústrias beneficiadas, mas também porque a medida passou a contemplar indústrias cujas elasticidades do emprego em relação aos tributos são maiores, fazendo com que o aumento no nível de emprego passasse para 5,14%. Além disso, os resultados mostraram que a variação no nível de emprego é maior para o trabalho do tipo blue collar do que para o trabalho do tipo white collar. Isto está em acordo com a teoria econômica sobre o mercado de trabalho porque um tipo de trabalho com atribuições mais específicas e que envolve maior aquisição de conhecimentos, como é o trabalho white collar, deve ser mais afetado por outras variáveis que não os tributos. / The Brazilian government and policy makers have been concerned about the industrial performance lately, which made industrial policies recover its relevance in the political agenda since 2004. One of the most important of such policies was the payroll tax exemption to some industries, which was created to reduce labor costs, and to stimulate the Brazilian industry production, employment and competitiveness. The high coverage of this policy resulted in an important reduction in the Social Security contribution: the policy has already reduced the contribution in BRL20 billion from 2011 to 2013. Both the program expenses and the perceived need to increase Brazilian industrial competitiveness are reasons to carry out a formal empirical evaluation. However, there are many factors to control in order to identify the policy effects by the Randomized Control Trials, which makes this approach hardly suitable. The methodology to estimate market imperfections developed by Petrin e Sivadasan (2013) is helpful in this case. These estimates represent any phenomena that moves the market away from competitive equilibrium, such as mark ups, firing and hiring costs, capital adjustment costs, taxes and subsides. Therefore, the payroll tax exemption can be treated as a decrease in the gap for industrial sector labor market equilibrium, and this relationship between policy and market imperfections allows the policy effects identification. The variables used are from the Annual Industrial Research - Enterprise (\"PIA - Empresa\"), and were studied at the firm level for the period between 1996 and 2011. The results suggest that the policy increased the employment level in 0.84% considering only industries selected at the policy\'s first stage. The estimated effect on employment level increases to 5.14% considering also industries benefited by the policy after its expansions, which is related to higher elasticity of employment with respect to taxes for the industries included. Besides that, results show that most of the jobs created are blue collar jobs, which is in accordance with previous expectations since white collar jobs usually requires more skilled workers and, therefore, reacts more to other factors than taxes.

This research provides a comprehensive picture of the economic status of the U.S. catfish industry through investigating several critical economic aspects such as technological progress, functional production relationships in intensive systems, regulatory costs, and economic contribution of the industry. The use of primary data is a unique aspect of this work reflecting the economic realities of catfish farms. Primary data collected through extensive in-person farm surveys covered over two-thirds of the catfish production areas in the U.S. The results of the study provided evidence of intensification in the U.S. catfish industry through increased adoption of two relatively new alternative production systems viz; intensively aerated ponds (6,315 ha) and split ponds (1,176 ha). The use of complementary technologies such as hybrid catfish on 53% of the catfish producing area and increased fixed-paddlewheel aeration rate of over 7.8 kW/ha also provided proof of technological progress on U.S. catfish farms. This study also identified critical factors contributing to productivity in increasingly adopted alternative production systems through two distinct production function models. Feed fed, as well as stocking biomass were found to be significant variables in both production functions. Results indicated further room for improvement in the use of inputs to increase production, especially in feed management. Along with identifying the nuances in the catfish industry, the study quantified regulatory costs on U.S. catfish farms at $45 million. Although faced with several hardships on the production front, the U.S. catfish industry contributes over $1.9 billion to the regional economy, supports more than 9,100 jobs, and generates over $78 million in tax revenues. The findings of the study serve a multitude of stakeholders including aquaculture farmers, researchers, Extension specialists, and policymakers who work towards improving the economic sustainability of the catfish industry as well as the U.S. aquaculture industry.

The purpose of this study was to explore and analyze which fifth-grade teacher inputs were the most important predictors of future outcomes of eighth-grade math students. This quantitative study looked at mathematical achievement through the lens of an education production function. The three inputs that were analyzed were fifth-grade teachers’ background; perception of professional development; and instructional practices and the relationship of those practices to achievement in eighth-grade math. In order to find the relationship between the above variables and student achievement, descriptive statistics, multiple correlations, and multi-variable regression analysis were conducted to examine which predictors had a stronger relationship between eighth-grade math outcomes than others. Taken as a whole, fifth-grade teacher math inputs in this study seemed to explain a small part of the variance regarding eighth-grade math achievement. As a whole, the more frequently students wrote and spoke about math in fifth grade as well as used math tools effectively, the better the outcome in eighth grade.