Credible Granger-causality analysis appears to require post-sample inference, as it is well-known that in-sample fit can be a poor guide to actual forecasting effectiveness. However, post-sample model testing requires an often-consequential a priori partitioning of the data into an "in-sample"...

The Granger-causal relationship between the size and dispersion of fluctuations in sub-components of the US Consumer Price Index (CPI) is examined using both in-sample and out-of-sample tests and data from January 1968 to December 2008. Strong in-sample evidence is found for feedback between...