Stocks‐to‐use ratios and prices as indicators of vulnerability to spikes in global cereal markets

We identify critical stocks‐to‐use ratios (SURs) for major grains and for an index of total calories from these grains. The latter appears to be a promising indicator of vulnerability to large price spikes when the current price shows no cause for concern. More generally, our results suggest that stocks data, though no doubt unreliable, can be valuable complements to price data as indicators of vulnerability to shortages and price spikes.