If I'm reading this correctly, he says that the CPI understates real inflation by 7%
per year. That means in 10 years, real prices will be about double what the CPI claims.
So if I bought a year's worth of stuff for $25,000 in 1997, the bls says I should be spending about $32,500 for approximately the same bunch of stuff in 2007, because the CPI-U went up about 30%.
But John Williams says that I'm really spending $65,000 today to buy that stuff.
(In adddition to reading the article you linked, I used the CPI calculator on the ShawdowStats website:
Shadow Government Statistics » CPI Inflation Calculator , it seems to have the same message.)
Am I mis-interpreting him?