The Optimal Harvest Decisions for Natural and Artificial Maturation Mangoes under Uncertain Demand, Yields and Prices

This study focuses on the decisions of picking, inventory, ripening, delivering, and selling mangoes in a harvesting season. Demand, supply, and prices are uncertain, and their probability density functions are fitted based on actual trading data collected from the largest spot market in Taiwan. A stochastic programming model is formulated to minimize the expected cost under the considerations of labor, storage space, shelf life, and transportation restrictions. We implement the sample-average approximation to obtain a high-quality solution of the stochastic program. The analysis compares deterministic and stochastic solutions to assess the uncertain effect on the harvest decisions. Finally, the optimal harvest schedule of each mango variety is suggested based on the stochastic program solution.

The Optimal Harvest Decisions for Natural and Artificial Maturation Mangoes Under Uncertain Demand, Yields, and Prices

This study focuses on the decisions of picking, inventory, ripening, delivering, and selling mangoes in a harvesting season. Demand, supply, and prices are uncertain, and their probability density functions are fitted based on actual trading data collected from the largest spot market in Taiwan. A stochastic programming model is formulated to minimize the expected cost under the considerations of labor, storage space, shelf life, and transportation restrictions. We implement the sample-average approximation to obtain a high-quality solution of the stochastic program. The analysis compares deterministic and stochastic solutions to assess the uncertain effect on the harvest decisions. Finally, the optimal harvest schedule of each mango type is suggested based on the stochastic program solution.

The commons problem in the presence of negative externalities

PurposeWhile the commons problem and the issues related to the negative externalities of harvesting have been studied extensively, there remains a need to bridge these two streams of studies to comprehensively investigate the implications of the strategic interactions among resource harvesters in the presence of such negative externalities. This paper aims to fill this gap.Design/methodology/approachThe authors study a common-pool harvest problem when the extractive activities leave behind negative externalities which affect the resource growth rate and reduce the stock beyond the extracted levels. Markov perfect noncooperative and optimal solutions are presented under different scenarios regarding considerations of negative externalities into harvest decisions.FindingsResults of the study suggest that, in the presence of such externalities, all parties must scale down their extraction in accordance with their externalities. The resource can be preserved by implementation of such harvest rule. However, failure to incorporate the externalities exacerbates the commons problem and can even lead to exhaustion of the biomass even if countries manage to cooperate and coordinate their harvest. Suggesting that if such externalities are large enough – which empirical literature suggests they are – then recognition and consideration of these externalities in the harvest decisions is as crucial as cooperation.Originality/valueThis paper provides a framework that is capable of incorporating the negative externalities of harvest activities into a bioeconomic game theoretic model and thereby providing a more real-world representation of the state of the common-pool resource management. While, the authors extend a well-known simple model, the model of this research study has the capacity to explain the widespread incidences of resource collapses. Therefore, the important policy implication is that agents should rigorously work together to understand the extent of the negative externalities of their harvests on the resources.

Smallholder rice farmers’ post-harvest decisions: preferences and structural factors

We study post-harvest decisions among Tanzanian rice farmers. Risk and time preference experiments are used to understand post-harvest decisions. In particular, we investigate storage and processing decisions, which according to our study can increase income by more than 50 per cent, but also introduce risk and time delays. Experimentally elicited risk and time preferences are statistically significant in explaining these post-harvest decisions. Impatient farmers are less likely to store paddy, and risk-averse farmers are less likely both to process and store paddy for future sales. Also, structural factors, such as milling costs, transportation costs and storage losses, influence the post-harvest choices.