gavreid
Pretty Words...
You are not the only one to suspect an artefact of analysis.
I am still open to the possibility of analysis artefact but that possibility has not survived the basic checks I did make.
- I did my due diligence and perturbed the analysis to check - and the oscillations remained.
- And if you actually look carefully at the daily source data on a simple graph you can see the oscillations.
I've always put these down to measurement artefact, some feature of the way tests are performed and analysed. Can you not drive the oscillations? The idea that they remain unperturbed is odd. A difference frequency beating between England and Scotland, for example, due to differing interventions - just a thought.