Agreed. If value is subjective, which it obviously is, then most standard economic measures have a huge amount of error in them. An economist would argue that the price system effectively aggregates supply and demand in order to convey value. This is in itself a fantasy as market prices even in those conditions most approximating Walrasin assumptions still come no where near meeting them. Then add the fact that 'vaule' out of necessity changes depending upon who is doing the evaluation....well, you get the picture.  

No raindrop believes itself responsible for the flood that follows.

Note that economists insist in NOT releasing the price data that is used to make those price indexes. All are funded with taxpayer money, but the only thing the taxpayer get is meaningless agregates.

Some personal rants at Bernard Salanie's blog