Estimating the benefits of plant breeding research: methodological issues and practical challenges

Impact assessment studies consistently show that the benefits generated by plant breeding are large, positive and widely distributed. Numerous case studies have concluded that investment in plant breeding research generates attractive rates of return compared to alternative investment opportunities, that welfare gains resulting from the adoption of modern varieties (MVs) reach both favoured and marginal environments, and that benefits are broadly shared by producers and consumers. But just how reliable are the results of studies that estimate the benefits of plant breeding research? This article reviews methods used to estimate the benefits of plant breeding research and discusses theoretical and empirical issues that often receive inadequate attention in applied impact assessment work. Our objective is not to question the validity of the theoretical frameworks commonly used to estimate the benefits of plant breeding research, but rather to examine problems that can arise when the widely accepted theoretical frameworks are used for empirical analysis. Most of these problems can be grouped into three basic categories: (1) problems associated with measuring adoption and diffusion of MVs, (2) problems associated with estimating benefits attributable to adoption of MVs, and (3) problems associated with assigning credit among the various plant breeding programmes that participated in developing the MVs.     

The impact of agricultural research in Africa: aggregate and case study evidence

This paper presents case-study results and aggregate data to evaluate the impact of research in African agriculture. Of 32 case studies, all but eight report annual returns over 20% and many are far higher, with most gains arising in the late 1980s and 1990s. Spurred by policy reforms and changing incentives, these innovations have led to sustained growth in aggregate cereal crop yields since 1985. Africa's belated ‘green revolution’ is based on new varieties (often with early maturation for drought escape), complemented by new management techniques (typically labor-intensive efforts to conserve soil moisture and build soil fertility).     

The distribution of benefits from public international germplasm banks: the case of beans in Latin America

The unrestricted international flow of genetic resources from international genebank collections is the source of perhaps one of the greatest impacts of international agricultural research. This paper examines the distribution across countries in Latin America of benefits generated from bean genetic resources held by the International Center for Tropical Agriculture (CIAT). The genealogies of commercial bean cultivars released since 1976, containing materials from the collection, are analysed to calculate for each country the source of the genetic resources used. All countries in the region are shown to be heavily dependent on imported genetic resources for their commercial cultivars. From the available information on the economic impact of these improved bean varieties, the share of economic productivity benefits associated with imported germplasm by country of origin is calculated. The benefits received by each country from improved bean germplasm are compared with the contribution of that country's germplasm to other countries. Some of the patterns in the flow and use of genetic resources are analysed.     

Efficiency,total factor productivity and returns to scale in a sustainable perspective: An analysis in the European Union at farm and regional level

For global sustainability it is imperative to find a balance across the three main components of sustainable development which are the economic, social and environmental aspects. However, it is not a simple task to make these contexts compatible, usually because of economic pressures which transform them into opposed objectives. This framework occurs across several dimensions within society and the economy, where the agricultural sector is not an exception. The objective of this study is to analyse the efficiency, total factor productivity and returns to scale in an economic, social and environmental perspective in farms of the European Union (EU) regions through Data Envelopment Analysis (DEA) approaches. The research concerning the returns to scale will be complemented by the Keynesian models. Data obtained from the European Union Farm Accountancy Data Network (FADN) was considered. The results show that in maintaining or improving the levels of production in farms, it is often possible to greatly reduce, in some cases, the consumption of fertilizers and crop protection products. On the other hand, from a social perspective, some European Union regions are more generous in the salaries paid to farming workers and absorb more labour, which in a European context of unemployment, may be an interesting way to realistically look at and be engaged in the agricultural planning in a sustainable way, founding a balanced trade-off among the economic, social and environmental dimensions.     

Imperfect competition,functional forms,and the size and distribution of research benefits

The effects of functional forms for supply and demand on the size and distribution of the returns to research are examined under a range of forms of competition. Under perfect competition, the choice of functional form is relatively unimportant for the estimation of research benefits. Under imperfect competition, the combination of the choice of functional forms for supply and demand and the nature of the research-induced supply shift can have profound implications for the results. Functional form plays a much more important role than in the competitive model. The most important contrast is between the constant elasticity model and the linear model (along with various cases of a generalized linear model). These findings are illustrated using a combination of analytical results and numerical simulations.     

Assessing the returns to R&D on perennial crops: the costs and benefits of Pierce's disease research in the California winegrape industry

Several complicating issues arise in evaluating the returns to research into varietal improvements for perennial crops compared with annual crops. We elucidate and address these issues in the context of a case study of research aiming to develop varieties that are resistant to Pierce's disease (PD) of grapevines. PD imposes costs of over $100 million per year on the California grape industry, even with public PD control programs in place. Research projects to develop PD resistant varieties of grapevines are at various stages of completion. We describe the economic problems posed by PD, document the research programs undertaken to address the disease and present an economic assessment of the returns to the investment, which are conditional on other policies. Using a simulation model of the market for California winegrapes, we estimate the benefits from research, development and adoption of PD‐resistant vines as ranging from $4 million to $129 million annually over a 50‐year horizon, depending on the length of the R&D lag and the rate of adoption. In addition to these specific quantitative results the paper offers insight into the broader question of economic evaluation of damage‐mitigation technology for perennial crops.     

Food crops, exports, and the short-run policy response of agriculture in Africa

The response of agriculture to changes in relative prices is an important factor in the success of structural adjustment programs in Africa. In this paper I estimate supply functions for total agricultural output, food crops and export crops in 14 African countries for the years 1975 to 1990. Food and export crops are substitutes in production in the short run. Total agricultural output responds negatively to increases in export prices and positively to increases in food prices. A plausible explanation is that as farmers shift resources to export crop production, food supply falls in the short run, while the increase in export supply may take several years to materialize. The exchange rate is significant in explaining both food and export crop production and aggregate agricultural supply, suggesting that the exchange rate is acting as a proxy for excluded macroeconomic variables or that changes in the exchange rate are not passed immediately through to prices.     

Returns to public sector plant breeding in the presence of spill‐ins and private goods: the case of bean research in Michigan

This article illustrates a methodology for assessing economic returns to a publicly funded breeding program in the presence of private sector investments, and spill‐ins from other contemporary public institutions and past research efforts. The approach consists of determining yield gains from bean improvement research; applying these yield gain estimates to measure benefits attributable to different institutional players and time periods; and then assessing the benefit‐cost ratios of investments in a bean improvement program since 1980 by Michigan State University (MSU). The results indicate that investments in MSU's bean breeding program have yielded benefits to costs ratio in the range of 0.7 to 2.2, depending on the attribution rule used to estimate the benefits. The estimated benefit/cost ratios reported in this study are lower‐bound estimates, as they do not account for potential benefits from area planted to MSU varieties outside of Michigan (spillover effects), which was 1.5 times greater than the area planted to MSU‐bred varieties within Michigan in the period 1998–2002. The implications of the increasingly privatized bean seed markets for the role of public sector research in bean improvement research are discussed.     

The rise and fall of public sector plant breeding in the United Kingdom: a causal chain model of basic and applied research and diffusion

This paper examines the barley and wheat breeding programmes of the Plant Breeding Institute (PBI), which was the most successful public plant breeding institute in the UK, until privatization in 1987. The PBI's shares in barley and wheat seed sales are explained, showing that the success with barley was largely a matter of serendipity, whereas the wheat programme followed a more normal pattern. For wheat, the causal chain, or recursive, model decomposes the well-documented link between research expenditures and increases in agricultural productivity into three stages. These are the effects of R&D expenditures on basic research output, measured by publications, the effect of publications and applied R&D expenditures on trial plot yields, and the diffusion of the trial plot technologies, which raises yields on farms. Applying the model to the FBI's wheat varieties allows estimation of the lag structures. In contrast to the results for aggregate agricultural research, for a single plant breeding programme alone there is a considerable lead time before there is any response, followed by a lag distribution only a few years long. The returns to the R&D investments are calculated from the causal chain model, from single equation estimates and by evaluating the yield advantage of the PBI varieties. All three approaches give consistent results, which show that the returns to barley and wheat alone were sufficient to support the entire PBI budget and still give rates of return to applied research of between 14 and 25%. The return to the basic science expenditures of the John Innes Institute has a lower bound of 17%, but must have been even higher than for the PBI if the other Institutes were taken into account. The paper concludes by commenting on the effects of the privatization of the PBI.     

Productivity and farm size in Australian agriculture: reinvestigating the returns to scale

A positive relationship between farm size and farm productivity is often considered to be largely due to increasing returns to scale in farm production. However, using farm‐level data for the Australian broadacre industry, we found that constant or mildly decreasing returns to scale is the more typical scenario. In this study, the marginal returns to various farm inputs are compared across farms with different sizes. We found that large farms achieved higher productivity by changing production technology rather than increasing scale alone. The results highlight the disparity between ‘returns to scale’ and ‘returns to size’ in the industry, suggesting that productivity improvement among smaller farms can be made through increasing their ability to access advanced technologies, rather than simply expanding their scale.     

2015年土地科学研究重点进展评述及2016年展望—— 土地资源与利用规划分报告

研究目的:总结2015年国内外土地资源与利用规划方面的研究进展,展望2016年国内研究趋势。研究方法:文献调研法。研究结果:(1)土地资源领域,土地资源保护、土地生态等是国内外学者的共同关注热点,此外,国内学者还关注土地资源基础理论、土地资源分类与调查、土地资源评价等,国外学者对此关注较少;(2)土地利用规划领域,国内外土地利用/覆被变化研究分别偏重社会经济宏观驱动因素与具体微观驱动因素,国内土地利用规划研究注重编制技术优化、规划实施评估及规划协同,国外学者则注重规划理论、规划原则及政策属性的探讨。研究结论:创新土地资源基础理论研究;细化土地资源本底要素研究;构建自然资源资产分类与调查方法体系;开展国土空间合理利用评价,优化土地资源评价指标体系构建方法;加强农用地数量质量研究,深化生态保护红线管控机制研究;探讨土地利用规划促进统一空间规划体系的作用等将是2016年及未来土地资源与利用规划领域着重研究的方向。     

Efficiency of research investments in the presence of international spillovers: wheat research in developing countries⋆

Expenditures on agricultural research in the public sector, including the International Agricultural Research Centers (IARCs) have stagnated and in some cases, declined sharply in recent years. This has focused attention on issues of efficiency of agricultural research systems, especially the number, size, scope, type, and locations of their programs. This paper examines the issue of research efficiency through a case study of wheat improvement research in developing countries. The basic premise of this study is that the optimal level of research investment should be determined in a global model that incorporates direct research spill‐ins. An analytical framework is developed to determine the threshold levels of crop production in a country (or a region within a country) needed to justify crop improvement research programs of different sizes in the presence of spill‐ins from abroad. Spill‐in coefficients are estimated from yield performance of varieties of different origins grown across a range of environments. The model is then applied to analyze the efficiency of current investments in 69 wheat improvement research programs in 35 developing countries. A major conclusion of the paper is that given the magnitude of potential spill‐ins from the international research system, many wheat research programs could significantly increase the efficiency of resource use by reducing the size of their wheat research programs and focusing on the screening of varieties developed elsewhere. ©2000 Elsevier Science B.V. All rights reserved.     

Valuing the benefits of an urban park project: A contingent valuation study in Thessaloniki,Greece

This paper aims to estimate the non-market benefits derived from the potential development of a new urban park in the city of Thessaloniki (Greece). The city of Thessaloniki has up to now a very low rate of proportional green space per capita. On this context a large metropolitan park was announced, as part of a large-scale redevelopment project, but the final decision has not been made yet. In order to help policy makers to their final decision, an ex-ante valuation of the potential benefits of the park is carried out in this study. A contingent valuation survey was designed and implemented aiming to estimate the willingness to pay of local residents for the provision of this park, as well as to determine the spatial scale at which these values are assessed. The main finding of this study is that people living within 20 min from the reference site are willing to contribute a significant amount of money to support this project. Another interesting outcome is that the willingness to pay for this project was not considerably modified during a period of economic recession (2010–2013), which is mainly due to the growing public awareness of the importance of green spaces, as well as of the benefits of the planned park.     

Productivity in Indonesian agriculture: Impacts of domestic and international research

Total factor productivity growth contributed 38% of Indonesia's agricultural output growth from the mid-1970s to the mid-2000s. This study uses time series data analysed with an error correction mechanism to examine the contribution that Indonesian publicly funded agricultural research made to this outcome, allowing for other possible determinants of productivity growth, including international agricultural research, extension, government price policy and weather. The results imply a 27% real annual rate of return from a marginal increase in Indonesian agricultural research expenditure. Indonesia's public agricultural research explains virtually all of its agricultural total factor productivity growth between 1975 and 2006.     

中国城市地下空间研究范式的转移与扩张

研究目的:梳理城市地下空间研究与实践的进展,构建城市地下空间研究范式框架及其演进路径。研究方法:文献研究法、比较研究法、演绎归纳法。研究结果:(1)地下空间研究范式已经从建筑附属物范式转移到资源利用范式,并将进一步扩张到时空发展范式;(2)地下空间研究范式演进既有不同学科之间的范式转移,也有同一学科体系下循序渐进的范式扩张;(3)新的研究范式没有完全推翻原有范式,而是体现了与原有范式的包含、继承与交叉。研究结论:地下空间研究范式符合土地科学学科的演进规律,受土地科学学科范式的指导和约束,可以采用土地科学学科理论来加以研究。     

泸水县50农户退耕还林社会经济效益调查监测

以滇西北泸水县的50户农户为例,论述农户退耕还林社会经济效益调查监测方法、监测指标以及50户农户调查监测结果。     

2018年土地科学研究重点进展评述及2019年展望——土地资源、利用与规划分报告

研究目的：总结2018年国内外土地资源、利用与规划领域的研究进展,展望2019年国内研究趋势。研究方法：文献调查法。研究结果：2018年国内研究侧重于土地资源资产、土地生态状况评估、土地利用视角下的碳排放、土地利用及其评价、国土空间规划、村级土地利用规划等方面;国外研究主要集中在土地资源配置与保护、土地生态、土地利用变化与可持续性、土地利用规划实践与应用等方面。研究结论：2018年土地资源、利用与规划研究在基础理论层面探索了国土空间规划体系的重构,深入分析了空间规划、国土空间用途管制与自然资源监管的关系,进一步明确国土空间开发保护制度的科学内涵,构建土地利用研究的框架体系;在实践层面探讨自然资源资产负债表编制中土地资源的核算方法,深化乡村振兴、多规合一视角下的村级土地利用规划研究,提出国土空间规划体系建立的构想。2019年的重点研究方向为：构建国土空间规划体系、加强土地资源理论研究、探索自然资源资产负债表和村规划编制研究、深化节约集约用地和农村土地利用问题研究等方面。     

Economic Analysis of Animal Genetic Resources and the Use of Rural Appraisal Methods: Lessons from Southeast Mexico

Livestock diversity provides genetic alternatives that facilitate sustainable agricultural development. Despite this, animal genetic resources (AnGR) are being depleted at alarming rates. Subsidises available to production systems based on imported breeds are of several orders of magnitude greater than the costs of local breed conservation. Economic arguments for the conservation and sustainable use of threatened AnGR can be an effective means of establishing support for the development of appropriate enabling environments. Despite the importance of the economics of AnGR conservation, the subject has received limited attention. Reasons include: methodological difficulties inherent in valuing genetic resources; limited knowledge about appropriate analytical techniques; and lack of data regarding local breeds. As recent advances in economic valuation have eased methodological/analytical constraints, the issue of data availability has become critical. Data related to livestock keepers' preferences for different genetic resource attributes and the value placed on these across species, breeds and production systems are needed. Based on a study of a local pig breed in Mexico, this paper shows how the use of rural appraisal methods, in conjunction with recently developed analytical techniques, are capable of providing the data required for understanding the type and costs of interventions necessary to promote the conservation and sustainable use of AnGR.     

陕北能源基地水权初始分配与动态调整机制研究——以秃尾河流域为例

通过分析陕北能源重化工基地的经济发展和水资源概况,建立水权基本制度框架。针对微观层面用水单位动态变化的特征,重点探讨在初始水权分配的基础上,如何建立完善的水权动态分配机制,对用水单位的用水进行有效的监督、审查、奖惩和调整,实现水资源的高效利用,促进能源经济的发展。对秃尾河流域锦界工业园区的水权分配进行实例分析与计算。     

The firm size,farm size,and transaction costs: the case of hazelnut farms in Turkey

This study analyzes the effects of transaction costs on the size of hazelnut farms in Turkey. The study finds that higher land slope and higher variance of rain, as transaction‐cost‐increasing natural effects, lead to smaller hazelnut land holdings. High slope and weather variation can increase the costs of monitoring the laborers, make moving inputs or output up and down harder, limit the use of machinery, and reduce contractual performance of labor contracts. For farm production functions, land is a complex input with measurable interactions with nature. Contrary to common production theory approaches that take natural properties of land as given, the study develops a production function that incorporates natural properties, such as, slope and rain variance. The study utilizes two separate data sets for the estimations. The first data set explores the characteristics of hazelnut farmers, while the second one analyzes the regional characteristics of hazelnut farms.