I am stunned to see serious modelers argue that we should compare infection growth in different countries on absolute terms rather than per capita

You are telling me population size in no way contributes for a higher number of cases?

That might be true if countries were watertight universes, but it’s ridiculously false if they are in contact

Think about this way. Why do Portugal and Spain combined have more cases than each on its own. Presumably, because infection started in different spots independently. Or then because some infection vectors crossed the border.

If they were a single country, both factors would still be captured by the larger population. Ergo a larger population by itself corresponds to larger number of cases. And I bet I am still forgetting other factors

Reductio ad absurdum: if you believe that argument then you have to think that if the 50 states were independent they would all have the same number of cases as US has now. Excluding perhaps the very smalll ones with no room to grow before herd immunity

Theoretically that is true, but since we have two nagging variables called time and space things are more complicated

Here is another metaphor. A fire spreads through a forest. Obviously in initial stage size of forest might be seen as irrelevant to how many trees burn. But a larger forest has a greater chance more than a lightning strike will start a fire and second...

to mix the metaphors, if national borders cut across the forest, a larger country will have more burned trees because the same fire stays within its borders - while in small countries that fire would spread to foreign trees