952 resultados para Stochastic Frontier Production Function
Resumo:
An approach to incorporate spatial dependence into stochastic frontier analysis is developed and applied to a sample of 215 dairy farms in England and Wales. A number of alternative specifications for the spatial weight matrix are used to analyse the effect of these on the estimation of spatial dependence. Estimation is conducted using a Bayesian approach and results indicate that spatial dependence is present when explaining technical inefficiency.
Resumo:
We show that every twice-continuously differentiable and strictly concave function f : R+ → R+ can be bracketed between two C.E.S. functions at each open interval. In particular, for the Inada conditions to hold, a production function must be asymptotically Cobb-Douglas.
Resumo:
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.
Resumo:
This article aims to analyse the introduction of environmental issues in the context of the production function, which has been referred to as the organisational area to lead corporate environmental management. With that purpose, the theoretical references for corporate environmental management and the necessary alterations in production function have been organised to include environmental aspects, especially in terms of product and process development, quality management, and logistics. Considering that this research field still lacks empirical evidence for Brazilian companies, four case studies were conducted using companies located in the country. The environmental management maturity level of those companies tends to follow the rate with which the environmental issue is introduced in production sub-areas, especially in the product development process. However, in most cases we found that the companies had difficulties in structuring the insertion of the environmental dimension in logistics. The final notes point out the distance observed between what is recommended by international literature and the reality of Brazilian companies in the challenge of making the production function environmentally friendly.
Resumo:
Plant volatiles typically occur as a complex mixture of low-molecular weight lipophilic compounds derived from different biosynthetic pathways, and are seemingly produced as part of a defense strategy against biotic and abiotic stress, as well as contributing to various physiological functions of the producer organism. The biochemistry and molecular biology of plant volatiles is complex, and involves the interplay of several biochemical pathways and hundreds of genes. All plants are able to store and emit volatile organic compounds (VOCs), but the process shows remarkable genotypic variation and phenotypic plasticity. From a physiological standpoint, plant volatiles are involved in three critical processes, namely plant–plant interaction, the signaling between symbiotic organisms, and the attraction of pollinating insects. Their role in these ‘‘housekeeping’’ activities underlies agricultural applications that range from the search for sustainable methods for pest control to the production of flavors and fragrances. On the other hand, there is also growing evidence that VOCs are endowed with a range of biological activities in mammals, and that they represent a substantially under-exploited and still largely untapped source of novel drugs and drug leads. This review summarizes recent major developments in the study of biosynthesis, ecological functions and medicinal applications of plant VOCs.
Resumo:
Ray (1998) developed measures of input- and output-oriented scale efficiency that can be directly computed from an estimated Translog frontier production function. This note extends the earlier results from Ray (1998) to the multiple-output multiple input case.
Resumo:
Based on an order-theoretic approach, we derive sufficient conditions for the existence, characterization, and computation of Markovian equilibrium decision processes and stationary Markov equilibrium on minimal state spaces for a large class of stochastic overlapping generations models. In contrast to all previous work, we consider reduced-form stochastic production technologies that allow for a broad set of equilibrium distortions such as public policy distortions, social security, monetary equilibrium, and production nonconvexities. Our order-based methods are constructive, and we provide monotone iterative algorithms for computing extremal stationary Markov equilibrium decision processes and equilibrium invariant distributions, while avoiding many of the problems associated with the existence of indeterminacies that have been well-documented in previous work. We provide important results for existence of Markov equilibria for the case where capital income is not increasing in the aggregate stock. Finally, we conclude with examples common in macroeconomics such as models with fiat money and social security. We also show how some of our results extend to settings with unbounded state spaces.
Resumo:
This paper provides new sufficient conditions for the existence, computation via successive approximations, and stability of Markovian equilibrium decision processes for a large class of OLG models with stochastic nonclassical production. Our notion of stability is existence of stationary Markovian equilibrium. With a nonclassical production, our economies encompass a large class of OLG models with public policy, valued fiat money, production externalities, and Markov shocks to production. Our approach combines aspects of both topological and order theoretic fixed point theory, and provides the basis of globally stable numerical iteration procedures for computing extremal Markovian equilibrium objects. In addition to new theoretical results on existence and computation, we provide some monotone comparative statics results on the space of economies.
Resumo:
From a theoretical point of view, it is traditionally assumed that foreign firms possess a centrally accumulated firm-specific technological advantage over domestic firms (see, for example, Findlay, 1978; Dunning, 1979). Given a sufficient level of absorptive capacity and human capital, domestic firms in host economies are able to benefit from various externalities stimulated by the presence of foreign firms.
Resumo:
We propose the use of stochastic frontier approach to modelling financial constraints of firms. The main advantage of the stochastic frontier approach over the stylised approaches that use pooled OLS or fixed effects panel regression models is that we can not only decide whether or not the average firm is financially constrained, but also estimate a measure of the degree of the constraint for each firm and for each time period, and also the marginal impact of firm characteristics on this measure. We then apply the stochastic frontier approach to a panel of Indian manufacturing firms, for the 1997–2006 period. In our application, we highlight and discuss the aforementioned advantages, while also demonstrating that the stochastic frontier approach generates regression estimates that are consistent with the stylised intuition found in the literature on financial constraint and the wider literature on the Indian credit/capital market.
Resumo:
Estudou-se atraves de um experimento em blocos ao acaso, os efeitos de quatro niveis de nitrogenio, em diferentes condicoes de umidade, sobre os estagios de crescimento, embonecamento, formacao de graos e prdutividade do milho (Zea mays L.) e as relacoes entre a produtividade e os tres primeiros estagios. Os fatores da resposta de producaobaseados na equacao de Doorenbos e Kassam variaram acentuadamente, nao so com os diferentes estatios de crescimento, mas tambem com diferentes niveis de nitrogenio e os diferentes niveis de agua. Assim, esta equacao nao pareceu ser valida para explicar a resposta de produtividade a niveis de agua. Sugeriu-se um equacao linear modificada. Nesta equacao, a intercessao K1 e inclinacao K2 sao os fatores da resposta de producao. Estes fatores para a cultura do milho foram desenvolvidos para todos os quatro estagios de crescimento e nveis de nitrogenio. Pode-se obter uma eficiencia media do uso de agua, em termos de produtividade, de, aproximadamente, 57,5 kg/ha-cm de agua, sendo, contudo, pequeno o incremento, em face dos niveis crescentes de nitrogenio aplicado ate 120 kg/ha. Os coeficientes de cutura (Kc) calculados estao muito abaixo da estimativa da FAO, para todos os niveis de nitrogenio. Por essa razao, deve haver consideravel economica de agua se estes coeficientes forem usados em lugar da estimativa da FAO. A informacao mostradapode imediatamente ser utilizada para turno de irrigacao e para projetos de irrigacao suplementar planejado para as condicoes doe Nordeste do Brasil.
Resumo:
This paper uses data on the world's copper mining industry to measure the impact on efficiency of the adoption of the ISO 14001 environmental standard. Anecdotal and case study literature suggests that firms are motivated to adopt this standard so as to achieve greater efficiency through changes in operating procedures and processes. Using plant level panel data from 1992-2007 on most of the world's industrial copper mines, the study uses stochastic frontier methods to investigate the effects of ISO adoption. The variety of models used in this study find that adoption either tends to improve efficiency or has no impact on efficiency, but no evidence is found that ISO adoption decreases efficiency.