Is it really odd to measure relative to the actual natural base rate of inflation, which is negative in a healthy economy, instead of ignoring opportunity cost and arbitrarily assigning zero as the base rate? If an economy's natural rate of inflation would be -3%, but government monetary expansion keeps it at zero, are you just going to pretend there's no inflation?
Some economists do define it that way, but that wasn't my argument. However, I do see your point if we define inflation as strictly the rise in prices, which certainly is the most common definition. My reasoning was off.
