But its all the same mechanisms ~ demand and supply in flex price markets and price leaders increasing prices in fix price markets. No matter what is driving inflation, it always has to go via those mechanisms.

If you have a pet theory that has to always be the cause, it gets tricky how to squeeze the right answer out of the data, but if you are actually looking for which of the causes are stronger at a particular point in time, you tell that from the data the same way you sort out any other cause in historical time.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.