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| Lyu, Syu-Jyun Larry; White, Fred C.; Lu, Yao-Chi. |
| The effects of agricultural research and extension expenditures on productivity in the United States are estimated during the period 1949-81 using data for ten production regions. The large time-series cross-sectional data base allows the translog production function to be estimated directly. Results from the translog and Cobb-Douglas production functions are compared. The results indicate that use of the Cobb-Douglas production function would overestimate the internal rate of return of agricultural research and extension expenditures in the United States and eight production regions. The total marginal product and internal rate of return for the United States are $8.11 and 66 percent, respectively. |
| Tipo: Journal Article |
Palavras-chave: Productivity Analysis. |
| Ano: 1984 |
URL: http://purl.umn.edu/29726 |
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| Watkins, K. Bradley; Lu, Yao-Chi; Huang, Wen-Yuan. |
| This study evaluates the long-term profitability and environmental impacts of variable rate versus uniform nitrogen application in seed potato production with nitrogen carry-over effects included. Seed potato yields were simulated for four different areas of a field using the EPIC crop growth model. A dynamic optimization model was used to determine optimal steady-state nitrogen levels for each area and the entire field. Average nitrogen losses and economic returns were evaluated for both uniform and variable rate nitrogen fertilizer. Variable rate nitrogen application was found to be unprofitable for the field when compared to uniform nitrogen application. Nitrogen losses for the field were about the same under both strategies. The results indicate... |
| Tipo: Journal Article |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 1998 |
URL: http://purl.umn.edu/31207 |
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| Lu, Yao-Chi. |
| Much research work has been conducted in recent years to evaluate the effects of research and extension.2/ Some of these efforts were conducted at the national aggregate level, while others were conducted at the regional or community levels. The methodologies used in those studies varied, but most of the studies were based on regression analysis of ex post data. There are several difficulties associated with the above ex post analyses. First, the time lags from the time of research resource commitment to production of extendable technology (invention), i.e., the leadtime, ranges from a few years to decades. It is difficult to collect time series data to accommodate a long leadtime. Besides, the average lead time is not known unless one studies specific... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1981 |
URL: http://purl.umn.edu/49074 |
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