Regarding the “core” and “full” CPI: both numbers are in the open for everybody to see. And most (if not all) of government benefits are based on the full CPI, not the core. So it’s unfair to blame the government for massaging the core figure, as they don’t actually use it to compute benefits. The core CPI is of great interest only to the Fed and to Wall Street.
I saw a graph of the full and core CPI over the past 20 years, and it looks exactly how one would expect it to look: big up and down spikes for the full index, while the core index looks like a moving average of the full CPI. Looking at the 2 graphs, it is quite clear that the core captures the overall inflation trend much better than the full index, which swings wildly.
On a side note, the government did indeed mess up the CPI calculation in the 70s, when, faced with high inflation, they started to change the formula to make it more friendly. Their credibility went out the window in the process, and long-term bond rates took off. They won’t make the same mistake again (at least, I hope they won’t). The bond market is not stupid, and, if it smells CPI foul play, then watch out!
