The less volatile U.S. economy: a Bayesian investigation of timing, breadth, and potential explanations

Using a Bayesian model comparison strategy, we search for a volatility reduction within the post-war sample for the growth rates of U.S. aggregate and disaggregate real GDP. We find that the growth rate of aggregate real GDP has been less volatile since the early 1980s, and that this volatility reduction is concentrated in the cyclical component of real GDP. The growth rates of many of the broad production sectors of real GDP display similar reductions in volatility, suggesting the aggregate volatility reduction does not have a narrow source. We also find a large volatility reduction in measures of final sales in the goods sector. We contrast this evidence to an existing literature documenting an aggregate volatility reduction that is shared by only one narrow sub-component, the production of durable goods, and is not present in final sales. We also document structural breaks in the persistence and conditional volatility of inflation that occurred over a similar time frame as the volatility reduction in real GDP.