MODELING ECOLOGICAL CONSTRAINTS ON TROPICAL FOREST MANAGEMENT: COMMENT

We comment on four aspects of Albers' [1] model of ecological constraints on tropical forest management. Albers structures her model in a highly asymmetric manner, with strong, uniform biases against development and in favor of preservation. Despite Albers' repeated claims that her model is "complete" and that it has significant implications for tropical forest management, we contend instead that the results of a truly general, empirically defensible model are inherently ambiguous. Spatial and intertemporal dimensions clearly matter, but they do not point as neatly in favor of preservation as Albers would have us believe. Note: Forthcoming in Journal of Environmental Economics and Managementforest, interdependence, irreversibility, management, uncertainty, Resource /Energy Economics and Policy, D81, Q15, Q23,

MACROECONOMIC SHOCKS, HUMAN CAPITAL AND PRODUCTIVE EFFICIENCY: EVIDENCE FROM WEST AFRICAN FARMERS

Little empirical work has quantified the transitory effects of macroeconomic shocks on farm-level production behavior. We develop a simple analytical model to explain how macroeconomic shocks might temporarily divert managerial attention, thereby affecting farm-level productivity, but perhaps to different degrees and for different durations across production units. We then successfully test hypotheses from that model using panel data bracketing massive currency devaluation in the west African nation of Cote d'Ivoire. We find a transitory increase in mean plot-level technical inefficiency among Ivorien rice producers and considerable variation in the magnitude and persistence of this effect, attributable largely to ex ante complexity of operations, and the educational attainment and off-farm employment status of the plot manager.Labor and Human Capital, O1, Q12, Q18,

Technological change and price effects in agriculture

This paper addresses the conceptual issues around the negative price effects of technological change on agricultural producers, explores price policy options vis-à-vis this problem, and reviews and compares experiences across Asian countries as they transformed their rural economies. It then draws implications for the challenge of achieving a smallholder-led agricultural revolution in Africa in the context of market liberalization.Small farmers ,technicological change ,market prices ,

AGROINDUSTRIALIZATION IN EMERGING MARKETS: OVERVIEW AND STRATEGIC CONTEXT

This article offers an overview for a special issue on agroindustrialization. It reviews eleven articles analyzing the agroindustrialization process in Latin America and Asia. It sets out a conceptual framework from the organizational economics and strategic management literature to enhance the understanding of the process of agroindustrialization from a competitive strategy point of view.Agribusiness, Industrial Organization,

Effects of Strip-cropping on Small Mammal Population Dynamics in Soybean Agroecosystems

Author Institution: Department of Zoology, Miami UniversityThe present study examined the effects of strip-cropping and harvesting practices on small mammal population dynamics in soybean agroecosystems. Small mammals were live-trapped in four treatments (three replicates each): soybean monoculture, soybean-clover, soybean-buckwheat, and soybean-corn. Peromyscus maniculatus was found in all four treatment types, whereas Mus musculus resided mainly in the soybean-corn treatment. Peromyscus population densities were significantly greater in the soybean monoculture during the week preceding harvest than in the soybean-clover strip-cropped treatment. Peromyscus population densities immediately increased following harvesting practices, then declined. Short-term changes in density were attributed to seed accessibility; long-term changes appeared to be in response to reduced crop cover resulting in increased predation. Populations of Mus were unaffected by harvest practices. Interestingly, more Peromyscus dispersed from strip-cropped treatments than from the monoculture (control) treatment. Female deer mice were found to have larger mean home ranges in the corn strip-cropped treatment than in the monoculture or buckwheat strip-cropped treatment suggesting an impact of spatial resource patterning on small mammal population dynamics

Thermomechanical fatigue in 9-12Cr steels: Life prediction models and the effect of tensile dwell periods

This paper is concerned with the assessment of life prediction models for thermomechanical fatigue (TMF), with specific application to P91 steel. A program of TMF tests, including dwell periods, are performed to determine the role of thermomechanical loading on fatigue life. As expected, fatigue life under conventional TMF testing (no dwells) is governed by maximum applied stress and inelastic strain-range. However, with the introduction of dwell periods, at maximum tensile stress during TMF loading, in-phase loading becomes the life-limiting case. This is attributed here to increased microstructural degradation and oxidation, associated with the dwell at peak temperature. Analysis of commonly used TMF life prediction models shows that the effect of dwell periods currently cannot be predicted for in-phase loading. Thus, it is concluded that physically-motivated approaches are required to successfully predict fatigue life under more complex (service) thermomechanical loading histories.Keyword