THE OPTIMAL CHOICE OF A VARIETY OF A SPECIES FOR VARIABLE ENVIRONMENTAL CONDITIONS
研究了当品种产量随环境条件非线性变化时，环境波动如何影响平均产量，并给出了在二次产量函数下选择最大化平均产量的品种的简单规则。
When yields of a variety are a non‐linear function of a relevant environmental condition, variability of this condition affects the average level of yields, and may favour one variety in comparison to another. When the yield function is strictly concave (exhibits diminishing marginal yield as a function of the environmental condition), heightened environmental variability increases the likelihood of the variety with the smallest change in marginal yield, the more tolerant one, maximising yield on average. However, if the yield function is strictly convex (increasing marginal yields are the case) increased environmental variability raises the likelihood of the variety with the greatest change in marginal yield, the less tolerant one, maximising yields on average. Examples are given, and simple rules are stated for choosing the variety that maximises average yields when yield functions are quadratic. The analysis can be adapted to decision‐making in which average profit or expected utility, rather than average yield, is to be maximised.