A copula‐based approach to the simultaneous estimation of group and meta‐frontiers by constrained maximum likelihood

Existing approaches to the meta‐frontier estimation consist of two stages where the estimates of the local frontier parameters obtained in the first step are used to estimate meta‐frontier parameters by means of a linear or quadratic minimisation procedure in the second. Since it was shown by Schmidt (Review of Economics and Statistics 58: 238) that the second step is equivalent to constrained maximisation of a likelihood function, we extend this idea and offer a copula‐based approach to the estimation of the parameters of both meta‐ and group frontiers in a one‐step setting. In this way, we ensure a single data‐generating mechanism for the estimated parameters, expand the set of potential meta‐frontiers and account for the fact that shocks to the individual production units may be correlated with shocks to the local technological environment as a whole. We apply our estimation methodology to a data set on the world agriculture and find that the deviations from the group frontiers are positively correlated with deviations from the meta‐frontier, which is a conclusion that is impossible to reach without accounting for stochastic dependence between the two deviation types represented by a copula.     

The maize frontier in rural South India: Exploring the everyday dynamics of the contemporary food regime

This contribution explores how new regions and crops are integrated in the contemporary food regime through a fieldwork‐based approach to maize cultivation in rural Karnataka, South India. As an intrinsic part of the industrial grain–oilseed–livestock complex, maize is an important component of the contemporary food regime. I argue that the expansion of maize at the village level follows commodity frontier dynamics, located at the conjuncture of processes “from above” pushing the industrial grain–oilseed–complex forward and processes “from below” that integrate maize in everyday livelihoods. Focusing on how villagers make use of maize in ways that cross, but simultaneously are differentiated along, lines of class and caste, this article seeks to contribute to our understanding of the everyday dynamics of contemporary food regime.     

Patterns in Technical Efficiency and Technical Change at the Farm‐level in England and Wales, 1982–2002

English and Welsh farm‐level survey data are employed to estimate stochastic frontier production functions for eight different farm types (cereal, dairy, sheep, beef, poultry, pigs, general cropping and mixed) for the period 1982 to 2002. Differences in the relative efficiency of farms are explored by the simultaneous estimation of a model of technical inefficiency effects. The analysis shows that, generally, farms of all types are relatively efficient with a large proportion of farms operating close to the production frontier. However, whilst the frontier farms of all types are becoming more efficient through time because of technical change, it is also the case that the efficiency of the average farm for most farm types is increasing at a slower rate. In addition, annual mean levels of efficiency for most farm types have declined between 1982 and 2002. The factors that consistently appear to have a statistically significant effect on differences in efficiency between farms are: farm or herd size, farm debt ratios, farmer age, levels of specialisation and ownership status.     

Technical Efficiency among Peasant Farmers Participating in Natural Resource Management Programmes in Central America

This study examines the extent to which technical efficiency (TE) is related to activities promoted by two natural resource management programmes recently completed in Central America. Data for a total of 639 farms operating in the hillsides of El Salvador and Honduras are used to estimate a household‐level input‐oriented stochastic distance frontier simultaneously with a TE effects model. The main finding of this study is that improvements in TE are financially beneficial to farm households while also contributing to environmental sustainability. The results also reveal a positive association between productivity and output diversification, and a positive relationship between TE and off‐farm income, human capital and agricultural extension.     

Spatial Causalities in Resource Rushes: Notes from the Finnish Mining Boom

Since the mid‐2000s, the world has seen an unprecedented expansion in corporate resource extraction. This global phenomenon has not been restricted to the Global South, but has also been, unexpectedly and interestingly, felt in the Global North in contexts that were considered to be ruled by political systems where the impacts of rapid resource extraction would not be felt. Between 2005 and 2010, for example, the volume of metallic ore and waste rock mining in Finland increased from fewer than 5 million tons to 46 million tons, mostly through the inauguration of four large mines in the east and north of the country. This paper examines the various explanations for the mining expansion, based on expert interviews, participant observation and a spatial analysis of the change dynamics. The importance and causalities in the control and divisions of social, physical and symbolic spaces are assessed, drawing on and interweaving the theories of Arrighi and Harvey, and conceptualizations of Moore and Bourdieu. A series of fertile conceptual tools for analysing the role of spatial dynamics in land‐use changes is developed and put to work in the empirical analysis. The results are significant for the literatures on spatial dynamics and Arctic land‐use change.     

土地利用科学中的“城乡交错带”概念辨析

研究目的:辨析现有文献中"城乡交错带"的有关概念,为其在土地利用科学中统一用法提供依据。研究方法:文献资料法。研究结果:(1)国内外文献中相关"城乡交错带"的概念众多;(2)不同概念的内涵各不相同。研究结论:(1)"城乡交错带"的不同提法,需根据研究领域的不同分别进行规范;(2)从概念内涵看,"城乡交错带"适用于土地利用科学研究领域。     

Efficiency in wine grape production: comparing long‐established and newly developed regions of South Africa

Efficiency, partly based on technology, is central to international competitiveness. This article applies a stochastic frontier inefficiency model to a panel of 77 wine grape farms in South Africa between 2005 and 2015 and allows the comparison of efficiency levels for the old established wine regions with those of newer entrants. Thus, we investigate whether experience plus first choice of location matters more than the follower's advantage of newer technology. In all regions, a greater share of permanent labor and increased supervision raised efficiency, while more inorganic fertilizer and less irrigation has the opposite effect. Innovations in trellising had insignificant effects (except in the old regions) but not replacing old vines reduced efficiency. However, a higher proportion of red varietals also lowered efficiency in the old regions due to a fall in the price of red wine as these farmers continued to concentrate on quality reds. The new regions compensated for falling prices by increasing crop size with irrigation and fertilizer and extending the area planted, but with less concern for quality. This appears to be more successful in efficiency terms, but as international demand for quality wine increases it may be a poor long‐term strategy.     

Resource use efficiency under self‐selectivity: the case of Bangladeshi rice producers

The paper jointly evaluates the determinants of switching to modern rice and its productivity while allowing for production inefficiency at the level of individual producers. Model diagnostics reveal that serious selection bias exists, justifying the use of a sample selection framework in stochastic frontier models. Results revealed that modern variety selection decisions are influenced positively by the availability of irrigation and gross return from rice and negatively by a rise in the relative wage of labour. Adoption of modern rice is higher in underdeveloped regions. Seasonality and geography/location does matter in adoption decisions. Stochastic production frontier results reveal that land, labour and irrigation are the significant determinants of modern rice productivity. Decreasing returns to scale prevail in modern rice production. The mean level of technical efficiency (MTE) is estimated at 0.82. Results also demonstrate that the conventional stochastic frontier model significantly overestimates inefficiency by three points (MTE = 0.79). Policy implications include measures to increase access to irrigation, tenurial reform and keeping rice prices high to boost farm returns and offset the impact of a rise in the labour wage which will synergistically increase the adoption of modern rice as well as farm productivity.     

Introduction to the special issue on the role of nonfarm income in poverty reduction: evidence from Asia and East Africa

In this special issue, we present seven studies that collectively attempt to investigate the role of non‐farm income in long‐term and short‐term poverty reduction in Asia and Africa. The first four studies out of the seven use long‐term panel data over two decades in the Philippines, Thailand, Bangladesh, and India. These studies show drastic increases in non‐farm income shares and corresponding declines in poverty levels over time, especially in the Philippines and Thailand. Education levels of household members and returns to education also increased significantly in these countries. The remaining three studies use cross‐sectional and short‐term panel data from Ethiopia, Kenya, and Uganda. These African studies show high proportions of poor households and low shares of non‐farm income that are somewhat comparable to the situation in the 1980s described in the Asian studies. Without the Green Revolution that provided stable farm income and potential financial resources to invest in children' education in Asia, it is not clear if African farm households can follow the Asian examples.     

Reterritorialization practices and strategies of campesinos in the urban frontier of Bogotá, Colombia

Much of the research on urbanization has focused on how rural populations move to cities for work opportunities. This paper takes a different perspective on the relations between rural populations and urbanization. The livelihoods of rural dwellers on the outskirts of the city of Bogotá in Colombia are increasingly affected by the expansion of urban activities and infrastructure. Therefore, urbanization takes place in the areas of residence of the rural populations; these people do not migrate to the city but, rather, the city migrates to them. Consequently, rural ways of life face growing competition from the production of commodities and services on the urban-rural fringe, including quarrying and landfills serving the needs of industries and urban populations. We explore how rural populations and their livelihoods have transformed as a response to these urban dynamics and the expansion of the city. We focus on the strategies that the rural populations employ to deal with the physical and socio-ecological impacts of this change. The defense of peri-urban livelihoods through these strategies is simultaneously social and spatial and has been partially successful. However, increasing social and environmental inequality, including worsening access to land, water and vital ecological functions, tends to lead to a general reduction in the quality of life in the urban frontier.     

2016年土地科学研究重点进展评述及2017年展望 ——土地资源、利用与规划分报告

研究目的：总结2016年国内外土地资源、利用与规划方面的研究进展,展望2017年国内研究趋势。研究方法：文献调研法。研究结果：2016年国外研究主要集中在土地资源价值评估与保护、土地生态、土地利用变化的驱动因素与生态影响、土地利用规划理念与技术等方面;国内研究侧重于土地资源配置、土地生态、国土空间分类、土地利用评价、土地利用管控策略以及规划协同与创新等方面。研究结论：2016年土地资源、利用与规划领域创造性地提出了基于土地科学发展时空锥理论而衍生的国土空间系统认知理论,探索了面向新型城镇化和生态文明建设的国土空间分类体系,提出一系列空间规划改革构想和建议。土地资源基础理论研究、国土空间合理利用评价、国土空间用途管制机制与国土空间规划体系的建立将是2017年及未来土地资源、利用与规划领域着重研究的方向。     

资源型城市转型及可持续发展研究综述

资源型城市转型及可持续发展是20世纪以来资源研究领域的热点问题。在文献调研的的基础上,对国内外资源型城市转型及可持续发展研究阶段和研究内容进行了系统的梳理和总结。其中,国外资源型城市研究经历了3个阶段,各个阶段研究内容、理论基础和研究重点各有侧重;国内资源型城市转型及可持续发展研究经历了资源型城市研究萌芽阶段、学术讨论起步阶段、转型及可持续发展全面研究和转型集中实践研究4个阶段,第三阶段是国内研究的"黄金期",包括9个方面重点研究内容。研究认为,建立和完善资源型城市转型及可持续发展的理论指导体系,创立和引入更加有效的方法进行定量分析,创新和总结转型模式与模型,是后续研究的重点。     

Territorialization in a closing commodity frontier: The Yasuní rainforests of West Amazonia

In Ecuador's Yasuní rainforests and the lived history of the Waorani that live there, the commodification of first rubber and then oil shaped territorialization into particularly violent form. The formative role of rubber production in the 19th century involved local despots' imposition of a regime of violence. Reacting to this violent capitalist system, individual Waorani forged new socio‐spatial territories through violence with rubber slavers and cooperation with the Taromenane, a people who continue to live in isolation. Today, an oil complex exerts control to bring the end of Yasuní's commodity frontier, even while the Waorani Nation and Taromenane hold legal rights to parts of the forests. In this article, I analyse how rubber and oil exploitation has unfolded as capitalist territorial violence, spurring Waorani and Taromenane social expressions and political mobilizations that are at times violent, but primarily not.     

Farmer responses to changing risk aversion,enterprise variability and resource endowments

The focus of this article is on assessing how risk aversion, enterprise variability and resource endowments affect farm land‐use decisions and economic returns. A theoretical model of a two‐enterprise, two‐constraint farm is developed, and then, an empirical illustration for an Australian farm is provided. The methodology used builds on previous expected mean‐variance (EV) models by incorporating land and budget constraints. The Kuhn–Tucker conditions of the EV model are examined to highlight that changes in resource endowments have larger effects on economic returns, than do changes in risk aversion or enterprise gross margin variability. It was also found that combinations of enterprise mixes that do not use all available resources can produce higher economic returns, relative to some enterprise mixes that use all available resources.     

Generalized Moments Estimation for Spatial Panel Data: Indonesian Rice Farming

We consider estimation of a panel data model where disturbances are spatially correlated in the cross-sectional dimension, based on geographic or economic proximity. When the time dimension of the data is large, spatial correlation parameters may be consistently estimated. When the time dimension is small (the usual panel data case), we develop an estimator that extends the cross-sectional model of Kelejian and Prucha . This approach is applied in a stochastic frontier framework to a panel of Indonesian rice farms where spatial correlations represent productivity shock spillovers, based on geographic proximity and weather. These spillovers affect farm-level efficiency estimation and ranking.     

基于Citespace的“水—能源—粮食”纽带关系研究进展

［目的］分析“水—能源—粮食”纽带关系有利于制定融合多学科多领域的综合性解决措施,为区域生态文明建设提供科学依据与决策参考。［方法］文章基于信息可视化软件CiteSpace,以Web of Science为数据源,从国家合作、核心作者、重要期刊、文献共被引、关键词以及突变词分析等方面,对1990—2019年“水—能源—粮食”纽带关系的研究进展进行可视化分析。［结果］自2011年波恩会议以来文献数量不断增长,以美国为中心的欧美国家研究较多,美国、英国、中国为位居前三的国家; Hoff H、Bazilian M和Fao等3位作者是该领域的奠基者,发表文献最多的期刊是Energy Policy,Environmental Science & Policy和Science,期刊分布较为均匀; 文献的突变点主要是Hellegers P（2008）、Rockstrom J（2009）、Waughray D（2011）、Scott CA（2011）、Hussey K（2012）、Bath H（2012）、Bizikova L（2013）和Rasul G（2014）。最近引用较多的主题是各部门协作的跨学科整合研究与提高应对全球复杂变化适应力; 研究前沿有城市地区、发展解释结构模型、因子分析、政策角度、整合角度、东南亚、南亚、可持续发展目标、作物生产、环境正义、流域、山脉研究、食物安全、能源安全,新兴前沿为可持续性; 能源与食物消耗、多元模型分离、全球变化、跨流域、东南亚、新水文视角是近几年学者们最关注的问题。［结论］应进一步构建共同支持性的概念框架和定义共识,探讨有效的量化方法和多元化的风险表征指标,加强纽带内部关系及其与气候与生态之间的关系研究。     

El Niño,La Niña,and world coffee price dynamics

Coffee is produced in equatorial and subequatorial regions of the world, which are also most affected by El Niño Southern Oscillation (ENSO). ENSO events have a tendency to amplify weather conditions such as droughts or excess precipitation in the affected regions, resulting in production shortage or excess supply, subsequently impacting agricultural commodity prices. In this research we assess effects of ENSO events on world coffee price dynamics using the monthly data between March 1989 and December 2010. We employ smooth transition autoregression framework to examine nonlinear dynamics of ENSO and coffee prices, and illustrate the results of this research using generalized impulse‐response functions. We find that ENSO events indeed have short‐term impacts on coffee prices. The research findings are of interest to coffee producers and intermediaries in the coffee markets as well as researchers in the fields of environmental and development economics.     

2017年土地科学研究重点进展评述及2018年展望——土地资源、利用与规划分报告

研究目的：总结2017 年国内外土地资源、利用与规划方面的研究进展,展望2018 年国内研究趋势。研究方法：文献调研法。研究结果：2017 年国外研究主要集中在土地资源的保护与管理、土地生态问题与生态恢复、土地利用变化驱动及影响、土地利用规划观念与技术等方面;国内研究侧重于土地资源配置、土地生态、土地利用及其评价、土地利用管控以及规划理论与实践创新等方面。研究结论：2017 年土地资源、利用与规划领域在基础理论层面进一步基于时空锥理论研究了规划机理,提出了科学认知 “多规合一”的理念,初步探索了供给侧结构性改革和土地利用规划的关系;在实践层面提出了“一张蓝图”、“多规合一”的技术路径,探讨了空间规划体系的建构与规划的核心任务,探索了村级土地利用规划的现存问题与未来编制工作重点。创新具有中国特色的土地利用规划理论和方法、构建国土空间开发保护制度、推动“土地用途管制”向“国土空间用途管制”发展、推进基于生态文明建设视角的空间规划体系创新、深化土地节约集约利用、土地领域供给侧结构性改革研究将是2018 年及未来土地资源、利用与规划领域着重研究的方向。