For the S factor loadings you say "First, unadjusted mortality rate, which is probably because northern regions have more old people who died of COVID.", but the mortality data is 2019, before COVID. The explanation of more old people in the north still makes sense though.
The link to a previous explainer, near the top, talks about concentration of industrial production capacity in the north and reads plausibly to account for geographical wealth disparities.
For the S factor loadings you say "First, unadjusted mortality rate, which is probably because northern regions have more old people who died of COVID.", but the mortality data is 2019, before COVID. The explanation of more old people in the north still makes sense though.
The link to a previous explainer, near the top, talks about concentration of industrial production capacity in the north and reads plausibly to account for geographical wealth disparities.