Guaranteed to be at least partly that, I would think, although I was expecting that between western European countries it would be relatively similar. One coul

Guaranteed to be at least partly that, I would think, although I was expecting that between western European countries it would be relatively similar. One could look at number of deaths per capita to compensate somewhat, although that leaves the question of whether or not true survival rates could also be different. USA's CDC estimate of the ratio is that the actual number of cases is 4.2*nbr of positive PCR tests. Which means that we only catch about 24% of the actual number of cases. I would think also that countries like Italy which had big waves early have a more serious undercount (for total cases in the pandemic) as compared to countries which first got it somewhat later, when PCR tests were more generally available.