A large number of previous studies suggest that many USDA forecasts are biased and/or inefficient. These findings, however, may be the result of the assumed loss function of USDA forecasters. We test the rationality of the USDA net cash income forecasts and the WASDE production and price forecasts between 1988 and 2018 using a flexible multivariate loss function that allows for asymmetric loss and non‐separable forecast errors. Our results provide robust evidence that USDA forecasters are rational expected loss minimizers yet demonstrate a tendency to place a greater weight on under‐ or overprediction. As a result, this study provides an alternate interpretation of previous findings of forecast irrationality.

中文翻译：

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多元不对称损失下美国农业部预测的合理性

大量先前的研究表明，美国农业部的许多预测存在偏差和/或效率低下。然而，这些发现可能是美国农业部预测者假设损失函数的结果。我们使用灵活的多元损失函数测试了美国农业部净现金收入预测以及 1988 年至 2018 年间 WASDE 生产和价格预测的合理性，该函数允许不对称损失和不可分离的预测误差。我们的结果提供了强有力的证据，表明美国农业部的预测者是理性的预期损失最小化者，但表现出倾向于对低估或高估施加更大的权重。因此，本研究提供了对先前预测不合理性发现的另一种解释。