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.

Some believe Panama Canal toll rates will increase dramatically as Panama's sovereignty over the Canal becomes complete at the end of this century. This paper focuses on the ability of Panama Canal management to extract additional toll revenues from United States grain traversing the Canal and the impact of increased toll rates on export grain flows. Analyses show toll rates established by a revenue-maximizing Canal management would exceed historical and current rates. A monopolizing Canal operator would have moderately increased Pacific port exports in the mid-1970's; whereas, in the 1979-82 period, Pacific port flows would have exceeded historical level.

This paper is concerned with analysis of economic feasibility of solar energy systems. Methodology for estimating energy output from different sized systems is briefly presented, and this is used to determine technical coefficients for a mixed integer model which optimizes the size of the solar heating unit for a particular use. An empirical example of hot water heating on a Georgia dairy is presented. Cost curves are provided for the dairy example to illustrate the effect of sizing on the economic feasibility of solar heating and to elucidate the structure of the optimal sizing decision.

Net present value analysis is used to derive the marginal bid price for a beef herd sire from after-tax net revenues and cash flow influenced by genetic improvements. Marginal bid price represents the additional amount a producer could pay, above the present value of the current beef herd sire, for a sire expected to exhibit superior performance as reflected by increased average weaning weights of offspring.

An analysis of the profitability of purchasing a breeding bull for a commercial beef cow herd is presented as an application. Several alternative scenarios illustrate the impact of selected determinants on the marginal bid price of a bull.

Forage production variability is incorporated into a decision theory framework for a beef producer in East Texas. The results suggest that the least risky, and also the most profitable, approach to intensive forage beef production is to plan for relatively poor weather conditions and low forage production. This results in a more diverse forage system and a smaller herd size than would be found optimal under the assumption of constant average forage production. These results also demonstrate that the assumption of constant average forage production may result in grossly exaggerated estimates of expected net returns.

This study compares equivalent annual rents for two alternative land uses in a region where farming and timber plantations coexist. The comparison is motivated by the possibility that rising timber prices may stimulate timber processors to compete for farmland. Prices, costs, and market rents are assumed to first follow existing trends and then to reach steady state values. Market rents are projected and capitalized for agriculture. Internal soil rents are capitalized for timber. The results show timber to have a comparative advantage on high fertility sites and suggest that timber might become a competitive land use at the intensive margin of the region's farmland base.

Results indicate that productivity growth has been a prime factor in Florida's ability to retain a competitive position in the United States domestic fresh winter vegetable market. Total factor productivity indexes and productivity growth rates are estimated for the production of four major vegetable crops in one or more of four production areas in Florida. Florida producers have exhibited substantial productivity growth over the 1969-70 to 1981-82 period.

Interest has grown in analyzing the impact of national imports of foreign beef on state agricultural sectors. In this study, an interfaced Hawaiian-national model is simulated for a change in national beef imports. Hawaiian and national impacts demonstrate wide variation in both sign and magnitude. Usefulness of state models is emphasized for situations where state impacts of national policies are of interest.

Irrigation water is produced within the irrigation subprocess of a farm. Water supply is identified for effective field water, which sets the upper bound on water available for plant use. Georgescu-Roegen process analysis concepts are merged with the neoclassical theory of cost as the underlying framework. The approach is illustrated for a permanent overhead system used in a Florida citrus grove. The marginal cost for the 2.54 centimeters application depth dominates all other depths for the higher water levels. Process analysis is an important analytical tool for increasing understanding of the features of irrigation water supply.

The purpose of this study was to develop a procedure for estimating future rail traffic that considers the relationship between the structure of a state's economy and rail freight traffic. The study expands the use of input-output models to include the forecasting of transportation demand. Georgia and Michigan case studies were used to test the forecasting capability of the input-output procedure. For Michigan's 1980 rail movements, the model predicted rail traffic to within 0.15 percent of actual traffic. For 1979 Georgia traffic, the model predicted within 4.3 percent of actual traffic. Various statistical tests indicate that the procedure was effective in forecasting rail freight traffic.

Estimation of the economic value of irrigation water is complicated by a lack of data on the price or marginal cost of water. Through econometric estimation of an aggregate total value product function, this paper obtains marginal irrigation water value estimates for the Middle Atlantic region. Additionally, the impact of temperature and soil conditions on aggregate production within the region is estimated. Ridge regression and covariance analysis are employed to deal with problems of multicollinearity and simultaneous equation bias, respectively. Estimates indicate a substantial and growing return to irrigation within the region.

Payment arrangements among members of a cooperative play a critical role in the performance of the cooperative. The impact of three payment systems is assessed for Florida sugarcane cooperatives through a bi-level programming model which incorporates both individual and collective behavior.

A dynamic model of daily cash and futures prices for cotton was developed using time series analysis. The time series model was included in a recursive Monte Carlo simulation model. Validation of the model was performed with a stochastic, dynamic simulation of the estimated model over the observation period 1975-1982 and with a static, deterministic out-of-sample forecast from December 9, 1981 through March 9, 1982. The model was then used to incorporate futures trading strategies into a policy simulation model.

Scherer's industrial organization model is modified to characterize the grain marketing system. The modified model identifies the important relationships between economic characteristics and the type of grain facilities found in three states; Alabama, Illinois, and Ohio. Multivariate linear discriminant analysis is used to identify the important basic supply, demand, and transportation variables within and among these states. It is concluded that the structural differences among selected grain marketing regions can be explained by regional differences in basic supply, demand, and transportation variables. The findings suggest that Scherer's industrial organization model can be adapted to explain the diverse structure of the grain marketing system in selected states.

Development and commercialization of technologies that utilize on-farm energy sources are beset by uncertainty. Producer gas, a technology that allows wood to be converted to a gaseous fuel which can power internal combustion engines, is evaluated for irrigation systems using simulation modeling and stochastic efficiency analysis. For many market conditions, producer gas stochastically dominates diesel fuel for powering a center pivot irrigation system in terms of lower cost. Commercial potential exists, but experience with pilot installations is required to further reduce uncertainty.

In this study, both the Rotterdam model and the double logarithmic model were used to estimate the demand parameters for fruit beverages. The results show that: (1) under the conditions of block-independence and predetermined price changes, the Slutsky matrix for fruit beverages is symmetric and negative definite; (2) own-price elasticity estimates from both models are about the same; and (3) income elasticity estimates and cross-product relationships from the two models are not compatible.

This paper describes a microcomputer software package, IO/EAM: An Input-Output Economic Assessment Model, which was developed at the University of Georgia through a joint extension-research effort. The package is a menudriven, user friendly program that is designed to be used by county extension agents, researchers, and other extension personnel to estimate the economic impact of changes in county economies. The program employs an input-output model that provides users with a locally based, easily updated source of economic intelligence. Use of input-output techniques allows users to estimate the impact of changes in county economies on an industry-by-industry basis and to account for the interdependencies among these industries in a county.

An economic threshold of agricultural pest management is derived. Results provide a method for researchers to use in making improved pest control recommendations to farmers without farm level decisionmaking. An empirical illustration for lesion nematode management in irrigated corn is given and directions for further research are indicated.

The risk effects of irrigation scheduling in a sub-humid climate have been well documented recently using approximations of the variance of net returns. A method to determine the exact variance of net returns assuming only multivariant normality is presented. The approximation technique in contrast to the method presented in this research was shown to have a non-uniform effect on the variance of net returns of each schedule.