Uncertainty and Change: Survey Evidence of Firms' Subjective Beliefs

This paper studies how managers plan under uncertainty. In a new panel survey of German manufacturing firms, we observe both forecasts of sales growth and a quantitative measure of subjective uncertainty. We show that subjective uncertainty reflects change experienced by firms: It is high when growth is either unusually low or unusually high. Subjective uncertainty is more than conditional volatility; while more volatile firms are typically more uncertain, experienced change alone increases uncertainty, consistent with a model of learning. Uncertainty over our sample is mostly idiosyncratic but varies substantially over time and leads managers to plan lower employment and prices.