DISTRIBUTION CHOICE UNDER NULL PRIORS AND SMALL SAMPLE SIZE

Defining appropriate probability distributions for the variables in an economic model is an important and often arduous task. This paper evaluates the performance of several common probability distributions under different distributional assumptions when sample sizes are small and there is limited information about the data.Research Methods/ Statistical Methods,

Stochastic Optimization: An Application to Sub-Arctic Dairy Farming

The paper demonstrates how a deterministic farm linear programming (LP) model can be made stochastic and simulated using Solver and Simetar© in Excel©. The demonstration is conducted with an LP-model for a dairy farm for a sub arctic region of Norway. The income risks arising from variation in milk and crop yields due to winter damage in leys and pastures have been quantified for farms demonstrating low, medium and high forage yield risk. The estimated distribution of farm profit will be skewed to the left, indicating a downside risk. In the presence of risks, farmers maximize income by producing the milk quota with using surplus forage for meat production. The analysis demonstrated here may assist farmers and farm managers in improving sensitivity analysis for risky variables in farm LP models.dairy production, Northern Norway, stochastic optimization, stochastic simulation, yield risks, Livestock Production/Industries,

Comparison of Alternative Safety Net Programs for the 2000 Farm Bill

As Congress begins its debate for the 2002 farm bill, there have been calls for a counter cyclical safety net that will provide a better basis for targeting longer term planning than exists with ad hoc emergency assistance. Further subsidization of the multi-peril crop insurance (MPCI) program has been proposed, as well as reliance on a farm and ranch risk management (FARRM) account to help farmers. A whole farm revenue income support program and several variations of national income supplement programs have been put forward. A comprehensive analysis of different safety net alternatives using a common methodology is needed so farmers and policy makers can make objective comparisons. The objective of this paper is to quantitatively analyze the economic effects of alternative safety net/insurance programs on farmers in the Southern United States. The objective is accomplished by simulating representative crop farms in the South over the 2001-2005 planning horizon for alternative safety net options. The simulated net present value distributions for the farms are compared using certainty equivalents to determine the value of alternative safety net options to feed grain, cotton and rice farms in the South.Agricultural and Food Policy,

The Fourth Positive System of Carbon Monoxide in the Hubble Space Telescope Spectra of Comets

The rich structure of the Fourth Positive System (A-X) of carbon monoxide accounts for many of the spectral features seen in long slit HST-STIS observations of comets 153P/Ikeya-Zhang, C/2001 Q4 (NEAT), and C/2000 WM1 (LINEAR), as well as in the HST-GHRS spectrum of comet C/1996 B2 Hyakutake. A detailed CO fluorescence model is developed to derive the CO abundances in these comets by simultaneously fitting all of the observed A-X bands. The model includes the latest values for the oscillator strengths and state parameters, and accounts for optical depth effects due to line overlap and self-absorption. The model fits yield radial profiles of CO column density that are consistent with a predominantly native source for all the comets observed by STIS. The derived CO abundances relative to water in these comets span a wide range, from 0.44% for C/2000 WM1 (LINEAR), 7.2% for 153P/Ikeya-Zhang, 8.8% for C/2001 Q4 (NEAT) to 20.9% for C/1996 B2 (Hyakutake). The subtraction of the CO spectral features using this model leads to the first identification of a molecular hydrogen line pumped by solar HI Lyman-beta longward of 1200A in the spectrum of comet 153P/Ikeya-Zhang. (Abridged)Comment: 12 pages, 11 figures, ApJ accepte

Economic Outlook for Representative Cotton Farms Given the August 2005 FAPRI/AFPC Baseline

The Agricultural and Food Policy Center (AFPC) at Texas A&M University develops and maintains data to simulate eighteen representative cotton operations in major production areas of seven states. The chief purpose of this analysis is to project those farms’ economic viability for 2005 through 2009. The data necessary to simulate the economic activity of these operations is developed through ongoing cooperation with panels of agricultural producers in each of these states. The Food and Agricultural Policy Research Institute (FAPRI) provided projected prices, policy variables, and input inflation rates in their August 2005 Baseline. Under the August 2005 Baseline, only the moderately sized Tennessee cotton farm (TNC1900) and Louisiana cotton farm (LAC2640) are considered in good liquidity condition (less than a 25 percent chance of negative ending cash during 2005-2009). Five cotton farms (TXSP3745, TXRP2500, TXMC3500, TXCB1850, and TNC4050) have between a 25 percent and a 50 percent likelihood of negative ending cash. The remaining eleven cotton farms have greater than a 50 percent chance of negative ending cash. Additionally, TNC1900 is the only farm in the set considered in good equity position (less than a 25 percent chance of decreasing real net worth during 2005-2009). Three cotton farms (TXRP2500, TXMC3500, and TXCB1850) have between a 25 percent and 50 percent likelihood of losing real net worth, and the remaining fourteen cotton farms have greater than a 50 percent probability of decreasing real net worth.Agribusiness, Agricultural and Food Policy, Crop Production/Industries,

GALEX Observations of CS and OH Emission in Comet 9P/Tempel 1 During Deep Impact

GALEX observations of comet 9P/Tempel 1 using the near ultraviolet (NUV) objective grism were made before, during and after the Deep Impact event that occurred on 2005 July 4 at 05:52:03 UT when a 370 kg NASA spacecraft was maneuvered into the path of the comet. The NUV channel provides usable spectral information in a bandpass covering 2000 - 3400 A with a point source spectral resolving power of approximately 100. The primary spectral features in this range include solar continuum scattered from cometary dust and emissions from OH and CS molecular bands centered near 3085 and 2575 A, respectively. In particular, we report the only cometary CS emission detected during this event. The observations allow the evolution of these spectral features to be tracked over the period of the encounter. In general, the NUV emissions observed from Tempel 1 are much fainter than those that have been observed by GALEX from other comets. However, it is possible to derive production rates for the parent molecules of the species detected by GALEX in Tempel 1 and to determine the number of these molecules liberated by the impact. The derived quiescent production rates are Q(H2O) = 6.4e27 molecules/s and Q(CS2) = 6.7e24 molecules/s, while the impact produced an additional 1.6e32 H2O molecules and 1.3e29 CS2 molecules, a similar ratio as in quiescent outgassing.Comment: 15 pages, 4 figures, accepted for publication in the Astrophysical Journa