Policy choices take time, and need to be done based on reasonable and continuing trends. Excluding volatile data helps keep policies on that path. Commodity prices do get reflected into core inflation as they change long term wages and business costs.
As an example look at Headline inflation in the chart from my previous post. If the US and/or the Fed had reacted to the spikes and valleys in those numbers during the recession of 2008/09, we might have seen an amplification of them, rather than damping.
I was hoping we could discuss these matters using facts -- but we seem to have trouble even agreeing on those.
