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| Registros recuperados: 69 | |
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| Pardey, Philip G.; Craig, Barbara J.. |
| Allocative decisions concerning public sector agricultural research appear to be driven by both supply and, politically mediated, demand forces. In-sample Granger and Modified Sim's tests, along with post-sample predictive tests, suggest that simultaneity issues should not be ignored when modelling the research expenditure-output relationship. The results also provide strong evidence that the impact of research expenditures on agricultural output persists for at least 30 years. These lags are substantially longer than those commonly used for agricultural research to date. The lagged effect of output on research appears much shorter, at something less than 10 years. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1987 |
URL: http://purl.umn.edu/13515 |
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| Lindner, Robert K.; Pardey, Philip G.; Jarrett, Frank G.. |
| Some hypotheses about the timing of farmers becoming aware of an innovation and the subsequent decision to use that innovation are derived from a recently developed, decision-theoretic model of the adoption process. They are tested using empirical evidence on the time taken by early adopters of trace element fertilisers in S.A. to discover and decide to use this innovation. The central role of information search in the adoption process is emphasised and it is postulated that various distance measures provide a useful measure of information availability and reliability. The results of the empirical analysis are consistent with the hypothesised relationships. Another finding is the importance of distinguishing between early adopters who are genuinely... |
| Tipo: Journal Article |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1982 |
URL: http://purl.umn.edu/22607 |
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| Liebenberg, Frikkie; Pardey, Philip G.; Kahn, Michael. |
| The 20th Century saw substantive shifts in the structure of agriculture and agricultural production in South Africa. Farm size grew, farm numbers eventually declined, and production increasingly emphasized higher-valued commodities, notably a range of horticultural crops. The real gross value of agricultural output grew steadily (by 3.32 percent per year) from 1910-1981, but declined thereafter (by 0.21 percent per year from 1982-2008). These long-run sectoral changes provide a context to present and assess an entirely new data series on public agricultural R&D (and related regulatory and extension) spending and associated scientist trends. South African agricultural R&D has been affected by a series of major policy changes. These are also... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2010 |
URL: http://purl.umn.edu/56688 |
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| Pardey, Philip G.; Koo, Bonwoo; Wright, Brian D.; Van Dusen, M. Eric; Skovmand, Bent; Taba, Suketoshi. |
| Worldwide, the number of genebanks and the amount of seed stored in them has increased substantially over the past few decades. Most attention is focused on the likely benefits from conservation, but conserving germplasm involves costs whose nature and magnitude are largely unknown. Because more resources spent on conserving germplasm often means less spent on characterizing the collection or using the saved seeds in crop-improvement research, knowledge of the costs of germplasm conservation has important, possibly long run, R&D management, policy, and food-security consequences. Moreover, these costs place a lower bound on the benefits deemed likely to justify the expense of saving this seed. In this paper we compile and use a set of cost data for... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Germplasm conservation; Gene banks; Plant; Maize -- Breeding; Wheat -- Breeding; Rate of return; Resource /Energy Economics and Policy. |
| Ano: 1999 |
URL: http://purl.umn.edu/97509 |
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| Alston, Julian M.; Craig, Barbara J.; Pardey, Philip G.. |
| Econometric studies of the effects of research on productivity have typically imposed arbitrary restrictions on the length and shape of the R&D on productivity and the estimated rate of return to research. This paper argues that the useful stock of public knowledge depreciates, if at all, only gradually, and we use this notion to develop a new model, which we test using data on aggregate U.S. agriculture. We reject the conventional specification in favor of a more flexible, dynamic, alternative model, in which the impact of R&D on productivity lasts much longer than in previous studies. Consequently, the real, marginal rate of return to public agricultural R&D in the United States is estimated to be less than 10 percent per annum, much smaller... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1998 |
URL: http://purl.umn.edu/16102 |
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| Alston, Julian M.; Pardey, Philip G.; Ruttan, Vernon W.. |
| Many researchers and commentators underestimate the length and importance of the time lags between initial research investment and ultimate impacts on the development and adoption of technological innovations. In both econometric studies of productivity and ex post and ex ante benefit-cost evaluations of research investments, researchers typically impose untested assumptions about the R&D lag, which can have profound implications for the results. In this paper we present a range of evidence on agricultural R&D lags including both aggregative analysis of U.S. agricultural productivity using time series data, and some specific details on the timelines for the research, development, and adoption processes for particular mechanical and biological... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2008 |
URL: http://purl.umn.edu/50091 |
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| Registros recuperados: 69 | |
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