Towards a theory for a practical optimisation model for a farm

Abstract

Total factor productivity in communal agriculture in Zimbabwe grew at 1.73% per annum from 1975 to 1990. Growth was negative before independence in 1980 and then reached over 8% a year, but turned negative again after 1985. The success following independence can be explained by the widespread adoption of modern technology, especially in maize production. Adoption was driven by the reorientation of government policy towards the communal sector, which led to improved price incentives and public provision of essential infrastructure investments, such as marketing depots and farm credit facilities. However, the high costs of support proved to be unsustainable and productivity declined from 1985.     

Location equilibria in a mixed duopsony with a cooperative

This work analyses a two‐stage price–location game between a profit maximising firm and a primary producers' cooperative. According to the results, the location equilibria are not fixed but depend on the intrinsic competitiveness of the spatial market. As the intrinsic competitiveness rises, the cooperative tends to be located closer to the middle point of the market. The limited differentiation in location entails an efficiency loss which is nevertheless smaller than that associated with the competition of two profit maximising firms (pure duopsony) on exactly the same spatial market. The superiority of a mixed duopsony lies in the fact that the resulting equilibrium locations entail lower total transportation cost relative to those of a pure duopsony.     

Nourishing urbanism: a case for a new urban paradigm

True sustainability demands that we seek to more than ‘prop up’ traditional approaches to our environment; rather, it requires that we redress current shortcomings in the planning and design of our urban environment at both bio-regional and local scales. Nourishing Urbanism proposes a shift in the urban and non-urban paradigm relating to energy, water and food; all face significant climate-related challenges—and are united by land-use policy, planning and design. We need a renewed planning and design framework for cities and regions that allows the retrofitting of today's urbanity, and prepares our cities for a new tomorrow. Nourishing Urbanism seeks to provide a malleable planning and design framework that embraces the symbiosis between urban and non-urban, and provides for the well-being of the human condition through recommending policies and technical solutions that readdress land use, ultimately impacting the security of our energy, water and soil resources, as well as infrastructure, food supply, health and design.     

发挥桥梁纽带作用 做好协会(学会)工作

<正>2009年,四川省粮食行业协会(学会)在省粮食局直接领导下,在全国粮食行业协会和省民政厅、省社科联的指导下,紧密联系各市、州粮食行业协会(学会)和全省粮食工作者,坚持以邓小平理论、     

Specifying a poly‐period development programme for a family farm

Most measures of inequality focus on the distribution of income and resources. A potentially important additional source of inequality stems from unequal property rights protection. The aim of the present paper was to examine the existence and patterns of systematic within-country inequalities in effective land rights in Rwanda. While a large qualitative literature discusses the comparative land rights of different groups, there is a lack of systematic quantitative evidence on the existence of land right inequalities. The results of estimations drawing on data on the land tenure arrangements of over 17 000 Rwandan households do indeed suggest within-country inequalities in land rights. In particular, despite recent reform efforts to improve women's land rights, a gender gap in land rights was observed that persisted throughout the 2005–2011 period studied, highlighting that institutional development takes time and that changes in de jure legislation do not automatically translate into changes in effective rights. Moreover, conflict-displaced households and households resettled to newly constructed village settlements all report weaker land rights than their respective comparison groups.     

The optimal export tax for a primary commodity in a vertical market

The conventional formula for the optimal export tax (derived from a partial equilibrium model that ignores importers’ welfare) is extended to include the deadweight loss to the domestic economy associated with the tax. Applying the extended formula to the tax Russia imposes on its exports of logs, results suggest ignoring the marketing channel causes the optimal export tax for a primary commodity to be understated. The degree of understatement increases as the supply of logs and processing/marketing inputs become less price elastic, and as buyer and seller power in the downstream (lumber) industry increases. For plausible values of model parameters, however, the degree of understatement is modest, less than 19%.     

Incorporating risk in a positive mathematical programming framework: a dual approach

In this study we develop a new methodological proposal to incorporate risk into a farm‐level positive mathematical programming (PMP) model. We estimate simultaneously the farm nonlinear cost function and a farmer‐specific coefficient of absolute risk aversion as well as the resource shadow prices. The model is applied to a sample of representative arable crop farms from the Emilia‐Romagna region in Italy. The estimation results confirm the calibration ability of the model and reveal the values of the individual risk aversion coefficients. We use the model to simulate different scenarios of crop price volatility, in order to explore the potential risk management role of an agri‐environmental scheme.     

Comparing the Profitability of a Greenhouse to a Vertical Farm in Quebec

Rapidly growing demand for year‐round fresh food, regardless of the weather or climate, is driving demand for controlled environment agriculture systems. Sales from greenhouses (GHs) are growing at 8.8%, while sales from vertical farms (VFs) are growing at 30%. It is commonly believed in industry circles that a VF cannot economically compete with a GH, due to the high cost of powering artificial lighting. Nonetheless, researchers have yet to analyze the economics underlying a VF, let alone compare the profitability of a VF to that of a GH. This research gap is particularly relevant to Canada, as it is uniquely positioned to be a leader in the VF market. Below, we report the results of a detailed simulation of the profitability of growing lettuce in a VF and in a GH located near Quebec City. Surprisingly, we find that the costs to both equip and run the two facilities are very similar, while the gross profit is slightly higher for the VF.     

林业企业创建学习型组织初探

文章分析了林业企业创建学习型组织的必要性,描述了林业学习型企业的特点,指出林业企业创建学习型组织的基本框架。     

Investigating stakeholder reactions to a bold salinity policy using a choice experiment

As a statement of policy, the Western Australian Salinity Investment Framework focuses attention on the benefits and costs of outcomes from the abatement of dryland salinity. Policy implementation would result in funds being spent unevenly across the landscape according to the value of assets protected, as well as the costs and effectiveness of treatments. This study used a choice experiment to investigate the reaction of rural stakeholders to the economic principles embodied in the Salinity Investment Framework. The results indicate that what matters is the type of assets protected, the risk of failure and the level of community involvement in the decision-making process; not the distribution of benefits. The results imply that the success of the Salinity Investment Framework, or other prioritised systems of resource management, in terms of community acceptance, does not necessarily rest upon distributional issues, and that other factors play a more crucial role. Policy makers could take this as a signal for the wider acceptance of decision frameworks that promote targeted investment according to public benefit.     

The construction of a HSR network using a ranking methodology to prioritise corridors

The construction of new high-speed rail (HSR) lines, in a climate of financial instability since the onset of the global crisis of 2007–2008, has reopened the debate among the scientific community. Support for the new projects is facing serious concerns over the extremely elevated costs of high-speed and the ability of today's governments to fund or co-fund these systems. This is the main reason the assessment of methodologies to prioritise the construction of new high-speed rail (HSR) corridors has recently become an important issue for transport planners in countries like the U.S. where HSR does not exist.The literature on ranking tools for prioritising HSR corridors is practically non-existent, even in Europe. In 2009, a new ranking methodology was developed and applied to 30,000 city pairs in the U.S. to determine their suitability for high-speed rail investment. As none of these lines has been constructed and none of them are in operation, this methodology has not been validated. The main objective of this paper is to analyse, validate and improve this ranking tool using data from a current HSR network: the Spanish one. Results show the consistency of the model as a preliminary approach to ranking pairs, mainly for the top first O–D relations; however the model fails to discriminate clearly between secondary groups of corridors. These deficiencies are chiefly due to the type of variables used by the model which ultimately, after improved, would provide policymakers with a useful tool when planning the construction of a new HSR network.     

家庭代际经济支持存在邻里效应吗?

基于2016年中国家庭追踪调查数据(CFPS),文章识别了家庭代际经济支持中的邻里效应,并对相关影响机制进行了检验。估计结果表明:在控制子女、父母等一系列特征变量后,社区邻里效应对家庭代际经济支持具有显著的正向影响。进一步分析表明,这种影响因家庭所在区域存在明显差异,表现为社区邻里效应对农村家庭代际经济支持的影响明显大于城镇家庭。此外,研究还发现:社区邻里效应对多子女家庭代际经济支持的影响明显大于独生子女家庭,对男孩家庭代际经济支持的作用显著大于女孩家庭和既有男孩又有女孩的家庭。最后,机制检验表明:在社区内部,子女追求社会地位,希望赢得他人尊重是社区邻里效应发挥作用的重要机制。文章从社区内部不同家庭互动角度解释家庭代际支持行为,为理解近年来我国不断增加的家庭代际经济支持现象提供了一个新的视角。     

Auctions as a Means of Creating a Market for Public Goods from Agriculture

The paper looks at the possibility of creating a market for environmental goods and services in the countryside by awarding conservation contracts to farmers on the basis of competitive bidding. Auctions have several theoretical advantages over alternative allocation mechanisms (such as standard-rate payments) because they allow the participants to deal with informational asymmetries and the uncertainty about the value of the (non-market) goods being traded. A formal model of bidding behaviour in ‘green auctions’ shows that bidding strategies are determined by the individual farmers' costs of implementing the conservation contracts and their beliefs about the maximum acceptable payment level, making the auction an imperfect cost revelation mechanism. Auctions can reduce the information rents accruing to farmers and can increase the cost-effectiveness of public goods provision. Strategic bidding behaviour in multiple-signup auctions as well as high transaction costs are potential sources of reduced efficiency.     

Agriculture as a provider of public goods: a case study for Norway

A valid argument for support is that subsidies are remedies for market failures. Agriculture contributes positively to public goods as food security, landscape preservation and maintenance of population in remote areas. Using a numerical model we simulate what Norwegian agriculture would look like if the only purpose of supporting agriculture was to provide such public goods. This is compared to the consequences of the Uruguay round in GATT and possible future EU membership for Norwegian agriculture. Although the GATT agreement will change agriculture in the desirable direction, the agreement puts no substantial pressure on the current agricultural policy. EU membership on the lines laid down by the accession treaty between EU and Norway prior to the referendum in 1994 would have given a stronger impetus towards the optimal solution.     

Multiple-use forestry as a boundary object: From a shared ideal to multiple realities

Today, multiple-use (or multifunctional) forestry is one of the main concepts guiding European forestry. While there is wide acceptance of the overall concept, here is a lack of coherence in definitions, policies and practices. Such outcomes indicate that multiple-use forestry (MUF) may contain the essential properties of a “boundary object”, i.e. something that is robust enough to conceptually unite different interests, but at the same time is flexible enough to encompass different practices in line with local needs and conditions. This study sets out to explore the conceptualization and implementation of MUF as a boundary object, examining the overall trends at an international level, and scrutinising the national specifics in three case countries: Lithuania, the Netherlands and Sweden. The review of international literature finds no consensus on what MUF is, beyond combining two or more forest functions or uses. The case countries show widely different approaches to conceptualizing and implementing MUF, not least in terms of spatial scales for integrating or segregating various functions. The analysis indicates that we should not expect instrumentation of MUF toward uniform guidelines to shape forestry practices throughout Europe. Rather it will continue to serve the profession as a boundary object that serves as a mediating concept between various interests while being inclusive of a wide set of forestry practices.     

夯实基础 提高水平 为全面推进现代林业建设提供坚实保障

2006年林业计划财务工作取得新的进展,达到了为争取并落实“十一五”开好头、起好步的目标。主要表现在规划突出了亮点,改革和资金落实突出重点,在保障改革、完善制度、加强引导、扩大开放、提高质量等方面有新的举措。2007年林业建设和经济发展的目标与任务是:营造林面积508万hm2,木材产量达10422万m3,实现林业产值10500亿元,主要林产品出口总额达540亿美元。2007年林业计财工作的重点达:组织编制好林业发展规划,做好相关政策的争取和落实工作,统筹安排生产建设计划和各项资金,切实强化项目管理和预算等工程监管,做好林业统计工作,等等。     

Regional economic impacts of a plant disease incursion using a general equilibrium approach*

The present study uses a dynamic multiregional computable general equilibrium (CGE) model to estimate the micro‐ and macroeconomic effects of a hypothetical disease or pest outbreak. Our example is a Karnal bunt incursion in wheat in Western Australia. The extent of the incursion, the impact of the disease or pest on plant yields, the response of buyers, the costs of eradication and the time path of the scenario contribute to outcomes at the industry, regional, state and national levels. We decompose the contribution of these individual direct effects to the overall impact of the incursion. This might provide some guidance regarding areas for priority in attempting to eradicate or minimise the impacts of a disease or pest. The study also introduces a theory of dynamic regional labour adjustment in which economic events may lead to both real wage differentials and worker migration between regions.