We don't really understand what has been driving inflation these last 25 years

From The Inflation Puzzle: Why Has it Move So Little for 25 Years? by Timothy Taylor. A fascinating topic even though there are few answers. It is well known that inflation is one of the few means of erasing government debt and given the aging of workforces, the baby-bust, the low savings rates, and high debt and deficits of government entities, inflation will most likely return to haunt us.

Taylor finishes with

Inflation is one of the basic outcomes of macroeconomic models, along with economic growth and labor market outcomes like unemployment rates. It is thus a little jarring to watch a recent Fed chair like Janet Yellen forthrightly accept that we don't really understand what has been driving inflation these last 25 years. But the admission is an honest one, and an invitation to consider the puzzle further.

I would expand this beyond inflation. We are accustomed to reporting a wide range of statistics which we rely on with little regard to the degree to which they actually reflect reality. In some cases the numbers do give a useful reflection of reality. In many cases, not so much.

We use them because we are accustomed to using them. Sometimes it costs too much to change. Sometimes using better measures would force policy changes which we do not like.