平均概率还是平均分位数更好?

Is It Better to Average Probabilities or Quantiles?

Management Science · 2013
被引 160
人大 A+FT50UTD24ABS 4*

中文导读

研究了平均概率和平均分位数两种聚合专家意见的方法,发现平均分位数预测更尖锐、方差更低,且在专业预测者调查的GDP增长和通胀数据中表现更优。

Abstract

We consider two ways to aggregate expert opinions using simple averages: averaging probabilities and averaging quantiles. We examine analytical properties of these forecasts and compare their ability to harness the wisdom of the crowd. In terms of location, the two average forecasts have the same mean. The average quantile forecast is always sharper: it has lower variance than the average probability forecast. Even when the average probability forecast is overconfident, the shape of the average quantile forecast still offers the possibility of a better forecast. Using probability forecasts for gross domestic product growth and inflation from the Survey of Professional Forecasters, we present evidence that both when the average probability forecast is overconfident and when it is underconfident, it is outperformed by the average quantile forecast. Our results show that averaging quantiles is a viable alternative and indicate some conditions under which it is likely to be more useful than averaging probabilities. This paper was accepted by Peter Wakker, decision analysis.

专家意见聚合概率平均分位数平均预测校准