Kelvin Balcombe

Bio: Kelvin Balcombe is an academic researcher from University of Reading. The author has contributed to research in topics: Willingness to pay & Mixed logit. The author has an hindex of 34, co-authored 132 publications receiving 4004 citations. Previous affiliations of Kelvin Balcombe include Imperial College London & University of Pretoria.

Determinants of technical efficiency of crop and livestock farms in poland

Abstract: La Pologne est l'un des pays d'Europe de l'Est candidats a une accession a l'Union europeenne, qui rencontre de graves problemes de restructuration agricole. L'article etudie l'efficacite technique, en 2000, d'exploitations agricoles individuelles polonaises specialisees en elevage et en grandes cultures. L'efficacite est estimee par la methode de frontiere stochastique, et sa variabilite statistique evaluee par la construction d'intervalles de confiance. L'article examine egalement les determinants de l'efficacite. Les resultats obtenus pas la methode de frontiere stochastique sont compares avec ceux obtenus par la methode de Data Envelopment Analysis (DEA). En moyenne, l'efficacite technique des exploitations d'elevage est superieure a celle des exploitations de grandes cultures. Pour les deux specialisations, la relation entre l'efficacite et la taille des exploitations est positive : les grandes exploitations sont les plus efficaces. Les resultats obtenus par la methode de frontiere stochastique sont generalement confirmes par la methode DEA. La qualite de la terre et le degre d'integration dans les marches d'aval sont d'importants determinants de l'efficacite. La faible education est un obstacle majeur a l'efficacite, en particulier pour les exploitations de grandes cultures. De plus, celles-ci utilisent beaucoup les marches de facteurs (terre et travail), alors que les exploitations d'elevage utilisent plutot leurs propres terres et le travail familial.

Bayesian Estimation and Selection of Nonlinear Vector Error Correction Models: The Case of the Sugar-Ethanol-Oil Nexus in Brazil

Abstract: Nonlinear adjustment toward long-run price equilibrium relationships in the sugar-ethanol-oil nexus in Brazil is examined. We develop generalized bivariate error correction models that allow for cointegration between sugar, ethanol, and oil prices, where dynamic adjustments are potentially nonlinear functions of the disequilibrium errors. A range of models are estimated using Bayesian Monte Carlo Markov Chain algorithms and compared using Bayesian model selection methods. The results suggest that the long-run drivers of Brazilian sugar prices are oil prices and that there are nonlinearities in the adjustment processes of sugar and ethanol prices to oil price but linear adjustment between ethanol and sugar prices.

Technical and scale efficiency of crop and livestock farms in Poland : does specialization matte r?

Abstract: L'efficacite technique et d'echelle des exploitations agricoles polonaises est calculee par la methode Data envelopment analysis. L'etude porte sur les differences selon l'orientation productive, en grandes cultures ou elevage, a deux dates de la transition, en 1996 et en 2000. L'article examine de plus la variabilite statistique des resultats d'efficacite. Ceux-ci sont revus a la lumiere des intervalles de confiance construits grâce au bootstrapping. En moyenne, les exploitations d'elevage ont une efficacite technique et d'echelle superieure aux exploitations de grandes cultures. L'efficacite d'echelle est toutefois tres elevee pour les deux orientations. L'inefficacite technique semble donc due principalement a une inefficacite technique pure, c'est-a-dire a une gestion inefficace. La faible education des agriculteurs en est une raison majeure. En 2000, 64% des exploitations d'elevage et 86% des exploitations de grandes cultures presentaient des retours d'echelle croissants. Ce resultat suggere des recommandations politiques afin de supprimer les incitations a garder une structure operationnelle fragmentee et de stimuler le marche de la terre. Il s'agit en particulier d'ameliorer la legislation concernant la location des terres et de modifier le systeme de retraite agricole.

Estimation and Inference in Econometrics

Abstract: Offering a unifying theoretical perspective not readily available in any other text, this innovative guide to econometrics uses simple geometrical arguments to develop students' intuitive understanding of basic and advanced topics, emphasizing throughout the practical applications of modern theory and nonlinear techniques of estimation. One theme of the text is the use of artificial regressions for estimation, reference, and specification testing of nonlinear models, including diagnostic tests for parameter constancy, serial correlation, heteroscedasticity, and other types of mis-specification. Explaining how estimates can be obtained and tests can be carried out, the authors go beyond a mere algebraic description to one that can be easily translated into the commands of a standard econometric software package. Covering an unprecedented range of problems with a consistent emphasis on those that arise in applied work, this accessible and coherent guide to the most vital topics in econometrics today is indispensable for advanced students of econometrics and students of statistics interested in regression and related topics. It will also suit practising econometricians who want to update their skills. Flexibly designed to accommodate a variety of course levels, it offers both complete coverage of the basic material and separate chapters on areas of specialized interest.

Forecasting, Structural Time Series Models and the Kalman Filter

Abstract: In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Bee declines driven by combined stress from parasites, pesticides, and lack of flowers

Abstract: Bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined, bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites accidentally spread by humans. Climate change is likely to exacerbate these problems in the future. Stressors do not act in isolation; for example pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple, interacting stressors is driving honey bee colony losses and declines of wild pollinators, but such interactions are not addressed by current regulatory procedures and studying these interactions experimentally poses a major challenge. In the meantime, taking steps to reduce stress on bees would seem prudent; incorporating flower-rich habitat into farmland, reducing pesticide use through adopting more sustainable farming methods, and enforcing effective quarantine measures on bee movements are all practical measures that should be adopted. Effective monitoring of wild pollinator populations is urgently needed to inform management strategies into the future.

Agriculture, Forestry and Other Land Use (AFOLU)

Abstract: Agriculture, Forestry, and Other Land Use (AFOLU) is unique among the sectors considered in this volume, since the mitigation potential is derived from both an enhancement of removals of greenhouse gases (GHG), as well as reduction of emissions through management of land and livestock (robust evidence; high agreement). The land provides food that feeds the Earth’s human population of ca. 7 billion, fibre for a variety of purposes, livelihoods for billions of people worldwide, and is a critical resource for sustainable development in many regions. Agriculture is frequently central to the livelihoods of many social groups, especially in developing countries where it often accounts for a significant share of production. In addition to food and fibre, the land provides a multitude of ecosystem services; climate change mitigation is just one of many that are vital to human well-being (robust evidence; high agreement). Mitigation options in the AFOLU sector, therefore, need to be assessed, as far as possible, for their potential impact on all other services provided by land. [Section 11.1]

Contemporary Guidance for Stated Preference Studies

Abstract: This article proposes contemporary best-practice recommendations for stated preference (SP) studies used to inform decision making, grounded in the accumulated body of peer-reviewed literature. These recommendations consider the use of SP methods to estimate both use and non-use (passive-use) values, and cover the broad SP domain, including contingent valuation and discrete choice experiments. We focus on applications to public goods in the context of the environment and human health but also consider ways in which the proposed recommendations might apply to other common areas of application. The recommendations recognize that SP results may be used and reused (benefit transfers) by governmental agencies and nongovernmental organizations, and that all such applications must be considered. The intended result is a set of guidelines for SP studies that is more comprehensive than that of the original National Oceanic and Atmospheric Administration (NOAA) Blue Ribbon Panel on contingent valuation, is more germane to contemporary applications, and reflects the two decades of research since that time. We also distinguish between practices for which accumulated research is sufficient to support recommendations and those for which greater uncertainty remains. The goal of this article is to raise the quality of SP studies used to support decision making and promote research that will further enhance the practice of these studies worldwide.