Within a month the regional factors have already diverged significantly from their initial value. This undercuts the claim that the regional factor represents a true inherent susceptibility to infection for a region. This means that the fact that regional factors cancel out differences in mask wearing is surprising and should be evidence against their hypothesis.
What does this divergence have to do with whether the “High Region Spread → High Mask → Lower Spread” model is true? Couldn’t that model be equally well true for any exogenous “region spread” factor, regardless of whether it’s changing month-to-month?
They are trying to explain the surprising fact that countries with high levels of mask wearing have correspondingly high “region spread” factors which cancel it out.
Their explanation is that this is because the regions most inherently susceptible to COVID-19 rationally respond by taking more protective measures (such as higher levels of mask wearing).
My point with the variance of the regional factor is that this makes it more likely that “region spread factor” is another term for “prediction error” rather than “inherent susceptibility”.
What does this divergence have to do with whether the “High Region Spread → High Mask → Lower Spread” model is true? Couldn’t that model be equally well true for any exogenous “region spread” factor, regardless of whether it’s changing month-to-month?
They are trying to explain the surprising fact that countries with high levels of mask wearing have correspondingly high “region spread” factors which cancel it out.
Their explanation is that this is because the regions most inherently susceptible to COVID-19 rationally respond by taking more protective measures (such as higher levels of mask wearing).
My point with the variance of the regional factor is that this makes it more likely that “region spread factor” is another term for “prediction error” rather than “inherent susceptibility”.