A Meta-Analysis of Technical Efficiency in Farming: A Multi-Country Perspective

The objective of this study is to undertake a meta-analysis seeking to explain the variation in average technical efficiency focusing on the agricultural sector. For this purpose, a meta-analysis of 126 technical efficiency studies on the agricultural sector of developing and developed countries was undertaken. In addition, the study contributes to cross-country productivity literature because the existing body of work in this area typically uses aggregate (i.e., national) level data to estimate total factor productivity and has ignored the technical efficiency component of productivity. The econometric results suggest that stochastic frontier models generate higher mean technical efficiency estimates than deterministic models, while parametric frontier models yield lower estimates than nonparametric. The difference between parametric and non-parametric frontiers is reduced when the translog specification is used. Also, frontier models using cross-sectional data produce lower estimates than those based on panel data. The econometric results also suggest that low-income countries (LICs) present a lower mean technical efficiency than high-income countries (HICs). A more detailed analysis reveals that Western European countries and Australia present, on average, the highest levels of mean technical efficiency among all regions after accounting for some methodological features of the studies. Eastern European countries exhibit the lowest estimate followed by Asian and African countries, while studies from Latin America and Caribbean countries, and from North American countries are in an intermediate position.Farm Management,

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

A Meta-Analysis of Technical Efficiency in Farming: A Multi-Country Perspective

The objective of this study is to undertake a meta-analysis seeking to explain the variation in average technical efficiency focusing on the agricultural sector. For this purpose, a meta-analysis of 126 technical efficiency studies on the agricultural sector of developing and developed countries was undertaken. In addition, the study contributes to cross-country productivity literature because the existing body of work in this area typically uses aggregate (i.e., national) level data to estimate total factor productivity and has ignored the technical efficiency component of productivity. The econometric results suggest that stochastic frontier models generate higher mean technical efficiency estimates than deterministic models, while parametric frontier models yield lower estimates than nonparametric. The difference between parametric and non-parametric frontiers is reduced when the translog specification is used. Also, frontier models using cross-sectional data produce lower estimates than those based on panel data. The econometric results also suggest that low-income countries (LICs) present a lower mean technical efficiency than high-income countries (HICs). A more detailed analysis reveals that Western European countries and Australia present, on average, the highest levels of mean technical efficiency among all regions after accounting for some methodological features of the studies. Eastern European countries exhibit the lowest estimate followed by Asian and African countries, while studies from Latin America and Caribbean countries, and from North American countries are in an intermediate position

Technical efficiency in developing country agriculture: a meta-analysis

A meta-analysis is perfonned to review empirical estimates of technical efficiency (TE) in developing country agriculture. The objective of the study is to contribute to a better understanding of the factors that influence estimates of mean TE. A data set of 51 observations of TE from 32 studies is used in order to test if specific characteristics of the data and econometric specifications account for systematic differences in the efficiency estimates. Results using the two-limit Tobit procedure indicate that factors such as primal versus dual, number of fixed inputs and number of variable inputs increase average TE estimates. On the other hand, using the Cobb-Douglas functional form and cross-sectional data yields a lower level of TE. Other factors, including the number of variables in the model, crop type, stochastic versus deterministic frontiers and sample size, do not seem to significantly affect estimates of TE across studies. © 200 l Elsevier Science B. V. All rights reserved

Biodiversity in South African fynbos and Mediterranean heathland

8 pages, 2 figures, 3 tables.The theory of convergence predicts that, given similar selective regimes, both present and past, unrelated ecological communities will show similar attributes. Mild Pleistocene climate, highly infertile soils, and similar fire regimes explain the remarkable convergence between mediterranean- type vegetation from South Africa (fynbos) and Australia (kwongan). Heathlands in the Aljibe Mountains, at the western end of the Mediterranean basin, constitute a single vegetation type within the Mediterranean region. We studied the association between endemism and plant life form in a flora from environmentally similar areas of the South African Cape region (fynbos) and the Aljibe Mountains by contingency table analysis. We included two non-acid, neighbouring areas to the latter region in the analysis as contrasts. We also compared the patterns of variation in three components of biodiversity (species richness, endemism level and taxonomic singularity) of fynbos and Aljibe heathland woody plant communities along similar soil fertility gradients by means of two-way ANOVAs. At the regional (flora) level, our results show two common features in the biological aspects of endemism between the two regions: (1) edaphic endemism and (2) association of endemism with the shrub growth form. At the community level, we detected strong similarities in the patterns of variation of endemism and taxonomic singularity of woody communities from both regions along an ecological gradient related to soil fertility. We interpret these similarities, both at the regional and community levels, as suggestive of convergence between fynbos and Aljibe heathland.This work was supported by a postdoctoral fellowship from the Spanish MEC to FO. It was also partially supported by Spanish DGICYT grants (PB91/ 894, PB95/551) to JA, DGES (PB97/1177) and FEDERCICYT grants (1FD97-0743-CO3-03) to TM, by the Mazda Wildlife Fund, the South African FRD and the Pew Charitable Trusts to MTS and RMC.Peer reviewe

Ano VIII, número 15

Espaço e Economia: Revista Brasileira de Geografia Econômica dedica sua 15.ª edição à publicização da segunda parte dos artigos apresentados no III Colóquio Espaço e Economia: Transformações no capitalismo mundial e a produção social do espaço: novos arranjos territoriais e a economia política do desenvolvimento, realizado na Universidade do Estado do Rio de Janeiro, entre os dias 10 e 12 de junho de 2019