One can try to tease out effects by looking at per-country or per-state breakdowns. It seems to me that:

- there are lots of different long term trends that vary by country

- some seem to have started too long ago to be tick tock or similar

- some countries see a pandemic drop and recovery

- this implies to me that:

(I) the pandemic had a strong temporary effect on average educational attainment (though I have strong priors here), and

(II) other things like long-term trends in teaching approaches, new distractions for students, or availability of AI for ‘cheating’ also have an impact

See coverage of the recent test results in the FT here: https://www.ft.com/content/724f8ecb-1e2b-4c7f-bbb6-14239abd5...