Sorry your OP seemed to be complaining that your ISK “doesn’t go as far as it used too” hence my replies. Your ISK does seem to go just as far IMO. Yes that is based on the MERS.
However you are correct that highly aggregated data can hide things. So looking at that data and saying, “Everything is fine, no problems,” could be hiding problems.
Now I wouldn’t say inflation is one of them. But there definitely can be others the that don’t show up in the MERS.