Stocks, Bonds, Bills, and Inflation’s Components

Despite the long history of calculating inflation betas, estimates of investment returns' response to the temporary and persistent components of inflation are strikingly absent. This article attempts to fill that void. Using officially reported inflation as well as real economic, survey, and time-series measures, the author decomposes inflation and estimates the reaction of stocks, bonds, and Treasury bills to its components. Persistent inflation is destabilizing, can harm economic growth, and, if this article's findings are reliable, is negatively associated with equity returns. But it is rare. Large relative-price changes are common, but equities may react indifferently to them. Portfolio inflation protection isn't free: It comes at the expense of allocations to higher-return asset classes. The author's findings might affect the amount of costly inflation insurance practitioners require.