But confounding factors average themselves out over long period of times. Hence why excess mortality is good, because you compare it to decades of data where the smaller effects even out.
If I can't get a heart surgery bc doctors unavailable and die, that's (on average) caused by covid. Sure, it's possible that my doc was unavailable at the time bc he hammered a finger, but "on average" over the timespan the only constant factor was covid (or covid-policy consequences).
If I can't get a heart surgery bc doctors unavailable and die, that's (on average) caused by covid. Sure, it's possible that my doc was unavailable at the time bc he hammered a finger, but "on average" over the timespan the only constant factor was covid (or covid-policy consequences).