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971.
Using data for a long panel of 90 developed and developing countries, this article explores the effects of research and development (R&D) and fixed capital stock on agricultural land productivity over the period 1961–2012. Instruments are used for R&D to deal with feedback effects and measurement errors. The results show very high social returns to investment in R&D and to fixed capital stock, suggesting that increasing investment in these factors are promising ways of arresting the increasing food prices due to increasing demand for animal protein, population growth, desertification, salinization, soil erosion, climate change, and decreasing growth in land productivity.  相似文献   
972.
This paper evaluates the impact of farmer field schools, an intensive participatory training program emphasizing integrated pest management. The evaluation focuses on whether program participation has improved yields and reduced pesticide use among graduates and their neighbors who may have gained knowledge from graduates through informal communications. The study utilizes panel data covering 1991–99 in Indonesia. The analysis, employing a modified "difference-in-differences" model, indicates that the program did not have significant impacts on the performance of graduates and their neighbors. Several plausible explanations for this outcome are discussed, and recommendations for improvements are suggested.  相似文献   
973.
Marketing Performance of Oklahoma Farmers   总被引:2,自引:0,他引:2  
  相似文献   
974.
We use a simple theoretical model of seasonal market participation in the presence of liquidity constraints and transaction costs to explain the ‘sell low, buy high’ puzzle in which some households do not take advantage of inter‐temporal price arbitrage through storage and sell output postharvest at prices lower than observed prices for purchases in the subsequent lean season. We test our model with data from western Kenya using maximum likelihood estimation of a multivariate sample selection model of market participation. Access to off‐farm income and credit indeed seem to influence crop sales and purchase behaviours in a manner consistent with the hypothesised patterns.  相似文献   
975.
This article assembles the results of three multicountry surveys on variety performance and adoption patterns to measure the impacts of maize research in West and Central Africa from 1981 to 2005, and uses cost data since 1971 to compute social rates of return on public investments in maize research in the region. Adoption of modern varieties increased from less than 5% of the maize area in the 1970s to about 60% in 2005, yielding an aggregate rate of return on research and development (R&D) investment of 43%. The estimated number of people moved out of poverty through adoption of new maize varieties rose gradually in the 1980s to more than one million people per year since the mid 1990s. Over half of these impacts can be attributed to international maize research at IITA and CIMMYT. The article concludes with a discussion of strategic options to enhance the impacts of maize research in the region.  相似文献   
976.
A Product and Process Model of the Technology-Sourcing Decision   总被引:1,自引:0,他引:1  
The technology‐sourcing decision traditionally has examined the choice either to innovate internally or to acquire technology from outside sources. The increasing complexity of this decision requires a move beyond the simple “make‐versus‐buy” dichotomy. We seek to test factors that influence the technology decision of subsidiaries for product and process technology across the continuum of options from internal development to outsourcing. We also explore concordance between the research streams of new product development and technology sourcing. Regression models are used to analyze data from 187 subsidiaries that suggest product and process technology development decisions sometimes are associated with similar factors and at other times they diverge. In particular, we find that external product and process technology acquisition decisions are associated negatively with differentiation goals and associated positively with product dynamism. While external product acquisition is associated negatively with a low cost goal and positively with increasing distance between primary marketing and R&D operations, external process technology acquisition is associated positively with high competitive intensity. Implications include the following: (1) While external product technology acquisition may provide quicker or even less expensive initial solutions, external reliance makes it difficult to maintain a long‐term positional advantage; (2) When greater distances separate key functional activities, external partners may provide solutions that are more responsive to local consumer needs, and the potential for improved communication may allow for quicker adaptation and increased flexibility; (3) In highly dynamic product situations, internal development, while providing greater control, can be expensive and can result in technologies that are not accepted by the marketplace; and (4) As competitive intensity increases, strategic imperatives may reduce the focus on product design and development and may require increasing concentration on manufacturing costs and efficiencies.  相似文献   
977.
In a series of recent papers, Domowitz, Hubbard and Peterson (DHP) have explored the temporal behavior of price-cost margins in a panel of 284 four-digit SIC industries. This paper reexamines DHP's apparent finding of more procyclical margins in concentrated industries, concluding that it is not robust. The result appears to arise from long-run trend correlations between margin and demand levels, rather than from short-run cyclical effects. Consistent with DHP, prices are found to be stickier and unit costs more countercyclical in concentrated industries. However, (1) an omitted variables bias is uncovered which substantially reduces the estimated cyclical effect on costs, and (2) prices are found to be more flexible in low concentration, low-PCM industries than DHP estimate. With prices more responsive to growth in demand and a countercyclical effect on cost of substantially lower magnitude, margins are thus estimated to bemore procyclical in less concentrated industries. This finding explains the relative rise in low concentration margins in the sixties which, in turn, helps account for the declining significance of the cross-sectional concentration-margins relationship.I would like to acknowledge helpful comments from Roy Rotheim, and two anonymous reviewers.  相似文献   
978.
979.
Freehand sketching is one of the most important and commonly used methods of generating and sharing budding ideas during the conceptual development portion of the preliminary phase of design. To develop one’s skills, prolonged practice, acquiring instant feedback and suggestions while practicing are invaluable. The two key and indispensable parts of learning draftsmanship are viewing and commenting on large numbers of free hand sketches. However, due to insufficient educational resources, instructors must spend most of their time engaged in class-room teaching, reducing the time allotted for one-on-one discussion and specialized assistance. Furthermore, the lack of sketch grading criteria can prevent students from developing proper insights into the essentials of sketching. As a result, students neither receive personalized feedback nor acquire adequate training in critiquing freehand sketching skills. These factors decrease learning effectiveness and negatively impact learning motivation. In order to solve this problem, this research has created a discussion platform on Facebook that utilizes the learning characteristics essential to developing proficiency in freehand sketching. It includes practice, observation, and comments. It has been found that this cultivates the subjects’ ability to judge freehand sketch quality and increases learning motivation and effectiveness through the process of peer-assessment. After participating in the one-semester teaching experiment, the abilities of the experimental group were significantly better than those of the control group, demonstrating that the online sketch discussion platform has a significant impact on freehand sketch learning.  相似文献   
980.
The work reported in this paper was carried out as part of a larger study on the uncertainties experienced by R&D scientists and engineers. It pertains to the development of a perceptual measure of technology, and its subsequent application to an R&D work context. Twelve perceptually based characteristics of technology were identified from literature, and formed the basis for a questionnaire. The survey methodology was adopted in this study. Responses to the questionnaire were elicited from sixty leaders of R&D teams belonging to the Telecommunications and Space Technology R&Ds. Analysis of data revealed that while certain characteristics seemed to constitute the 'core' of technology, the dominance of certain others varied between teams from the two R&Ds. This suggests that managerial implications from the perception of technology should be drawn with specific reference to the context. The study outlines some implications for R&D managers based on the profile of technology perception.  相似文献   
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