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941.
942.
Wetter areas of the Amazon basin exhibit lower rates of agricultural conversion. Previous analyses, using relatively aggregate data on land cover, have been unable to determine the extent to which this reflects limited access versus unfavorable agroclimatic conditions. This article uses census-tract level data for the Brazilian Amazon to relate forest conversion and pasture productivity to precipitation, soil quality, infrastructure and market access, proximity to past conversion, and protection status. The probability that land is used for agriculture or intensively stocked with cattle declines markedly with increasing rainfall, other things equal.  相似文献   
943.
Beef cattle producers were surveyed in Texas and Nebraska to investigate perceptions of sources of risk, the effectiveness of risk management strategies, and interest in further risk management education, particularly production risk, using probit analysis. Important decision variables identified are age, prior use of risk management tools, previous attendances of risk management education, and risk aversion. Severe drought and cattle price variability are identified as primary risk factors with potential to affect farm income. Extremely cold weather and disease are of less importance. Understocking pasture and storing hay are perceived most effective as risk management options.  相似文献   
944.
We consider a model for interest rates where the short rate is given under the risk-neutral measure by a time-homogeneous one-dimensional affine process in the sense of Duffie, Filipović, and Schachermayer. We show that in such a model yield curves can only be normal, inverse, or humped (i.e., endowed with a single local maximum). Each case can be characterized by simple conditions on the present short rate r t . We give conditions under which the short rate process converges to a limit distribution and describe the risk-neutral limit distribution in terms of its cumulant generating function. We apply our results to the Vasiček model, the CIR model, a CIR model with added jumps, and a model of Ornstein–Uhlenbeck type. Supported by the Austrian Science Fund (FWF) through project P18022 and the START program Y328. Supported by the module M5 “Modeling of Fixed Income Markets” of the PRisMa Lab, financed by Bank Austria and the Republic of Austria through the Christian Doppler Research Association. Both authors would like to thank Josef Teichmann for most valuable discussions and encouragement. We also thank various proofreaders at FAM and the anonymous referee for their comments.  相似文献   
945.
In this study, we develop a conceptual bioeconomic model of floriculture production with aesthetic benefits, wherein optimal decision rules depend on an intertemporal economic objective to maximize profits subject to economic and biological processes. Necessary conditions of the model identify optimal trajectories (e.g., simultaneous, single, or cycling controls) that define decision rules and economic thresholds for profit maximizing growers producing crops with aesthetic attributes. The necessary conditions also highlight intertemporal trade‐offs between aesthetic benefits and expected future net benefits of arthropod stocks, which have important policy implications. The model is applied to the greenhouse production system of ivy geranium.  相似文献   
946.
947.
I analyze a well-known and moving passage from John Steinbeck's novelThe Grapes of Wrath. This passage provides an excellent illustration of one of the central questions about corporate moral agency: Is corporate moral agency anything over and above the agency of individual human beings? The passage in question is a debate about whether or not the actions of a particular company are anything over and above the actions of individual human beings.  相似文献   
948.
If economists of technical change dealt with the public research/industry interface, the literature lacks empirical contributions. The present paper is clearly empirical. It investigates the efficiency of the relationships between public research institutions and industry from the point of view of the firm looking for solutions to its problems. The empirical work is based on the study of 32 cases of partnerships in France. It suggests that the efficiency of the interface depends on the context (nature of innovations, public research skills needed, duration of relationships, technological strategies of firms) and on the strategies of public research institutions (organizational linkages adopted). Four hypotheses are examined to test these efficiency conditions.  相似文献   
949.
Commodity markets have become key forces transforming upland livelihoods, social relations and landscapes in Vietnam and throughout Southeast Asia. This paper examines the processes of market formation and their effects on local livelihoods and social relations in a village of Vietnam's north-western uplands. The results indicate that villagers' reactions to new opportunities arising from decollectivization and market liberalization wove them into an increasingly intricate 'commodity web'. Differences among households widened as households with an initial advantage accumulated further advantages. Yet the relations governing access to land and product markets also provided a floor of subsistence for the disadvantaged. The findings demonstrate the need to interrogate commodity markets, investigate the practices and relations constituting them, and analyse how they distribute income and risks among the actors involved. The nature of commodity markets, together with the relations governing access to productive resources, influences processes of social differentiation in the uplands.  相似文献   
950.
The discovery of bovine spongiform encephalopathy (BSE), commonly known as ‘mad cow disease’, in Japan caused anxiety about consuming beef and beef products. As a result, there was a sudden fall in sales of beef that hurt the Japanese beef industry as well as major beef exporters to Japan. We analyse factors that affect Japanese consumers' willingness to pay (WTP) price premiums for BSE‐tested beef and estimate the mean WTP for BSE‐tested beef using data obtained from a consumer survey in Japan. A single‐bounded dichotomous choice contingent valuation model is used to recover the premium amount. We find that attitudes to food safety, reduction in beef consumption following the BSE outbreak, and being female all have a statistically significant positive effect on the WTP for BSE‐tested beef. Interestingly, demographic variables such as age and income do not affect the WTP, possibly indicating that the BSE scare similarly affected multiple segments of the population. In our sample, consumers are willing to pay a premium on average of greater than 50 per cent for BSE‐tested beef.  相似文献   
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