Effects of Selected Tax Policies on Management and Growth of A Catfish Enterprise
Abstract A multiperiod programming model was used to simulate the effects of lower marginal income tax rates, the soil and water conservation deduction, and the cash tax accounting option on firm growth for a “representative” farm operating in the Alabama Black Belt region. Results show the lowered marginal income tax rates associated with the Economic Recovery Tax Act (ERTA) of 1981 provide a positive growth stimulus to the modeled firm as measured by accumulated net worth over a 10-year planning horizon. The soil and water conservation deduction in general provides greater tax relief to the modeled firm than either the ERTA income tax rate changes or the cash tax accounting provision. Important complementary and substitute relationships were found to exist between marginal income tax rates and the various tax provisions studied, implying care must be exercised when attempting to evaluate the impact on farm firms of changes in tax policy.
Production, Price and Risk Factors in Channel Catfish Farming
Abstract The effects of several production/management, price and risk factors upon channel catfish profitability are analyzed with a multiperiod mixed-integer linear programming model. Factors analyzed include pond size and optimal stocking rates, alternate levels and trends in catfish prices, pond production losses and level of family consumption withdrawals. Model results indicate that channel catfish offer the potential to significantly increase farm rates of return while providing an avenue of intensive farm growth, without expanding the land base of the farm. However, the long range financial success of the firm was very sensitive to several of the management and risk factors examined.
Pyrite multiple-sulfur isotope evidence for rapid expansion and contraction of the early Paleoproterozoic seawater sulfate reservoir
Abstract Earthʼs oxygenation is often described in terms of two unidirectional steps at the beginning and end of the Proterozoic Eon, separated by a long-lived intermediate redox state. Recent work defines a more complicated path to oxygenation, exemplified by an apparent drop in oxidation state following the early Paleoproterozoic Lomagundi carbon isotope excursion. The timing of this proposed drop in oxidation state is not well constrained, and it is not clear how it relates to redox conditions during the remainder of the Proterozoic. Here we present a study of pyrite multiple-sulfur isotopes, supported by Fe speciation and organic carbon isotopes, from early Paleoproterozoic black shales. We find evidence for the rapid expansion of the seawater sulfate reservoir during the Great Oxidation Event at ca. 2.3 Ga followed by a subsequent contraction in the size of the seawater sulfate reservoir at ca. 2.05 Ga. This scenario is consistent with the emerging view of a rise and fall in surface oxidation state during the early Paleoproterozoic. Comparison of our new data to other records of the seawater sulfate reservoir suggests that the elevated sulfate concentrations that characterize the early Paleoproterozoic did not return until the late Neoproterozoic.