Big max index is a fun thing. First time I read about it, it felt like a more intuitive and connected to the real world metric. Compared to other economic metrics that is.

Then you live in the real world and realize it's not as good metric as you think it is.

Recently when returning to Europe, after the start of the Ukraine war (+ inflation) a lot of my friends asked if food prices had also went up in Japan. I said yes but not as much as Europe. Price of wheat surely went up but everyone eats rice there, so except for bakeries (not many of them) most people didn't feel much.

Bigmac index is not made or supposed to catch the difference in those details, but it seems like one of those economic metrics that are too often misused.

When the "happiness" index said Finland was a the happiest place, the first one to burst out laughing about how silly it is was my dad, a Finnish guy.

The legitimacy of an academic/scientific field can be somewhat roughly measured by how rigorous their measurement instruments and units are, and the conclusions the scientist try to make out of it.