I would strongly suggest that we not get hung up on debating or trying to estimate IFR or CFR. None of us in this forum have the data or experience to do this properly. We just wind up arguing about things we can't see.
I have found in my own experience as a statistician that it is very important to stay focused on things you can actually measure and get data for. Latent variables, censored observations and missing data can easily send one down imaginative paths that lead nowhere. What we often find is the we must make many more assumptions than we can test. We ultimately impose our own subjective biases as we select which results are worth sharing with others.
The when we share this with others we can run into conflict. But we wind up arguing not about observable facts, but over all the imaginative stuff we have no data. If we had the data, we wouldn't need to waste much time arguing.
So this is a clue, if you can't resolve an argument with someone, chances are you are not arguing about somethings you can actually quantify or gather good data for, or else someone in the argument is unwilling to yield to the data which is on hand. Past a certain point you are no longer engaged in science. You are probably just wasting time.
Among the tactics of "Merchants of Doubt," propagandists who try to undermine science, is the tactic the red herring. Get people to debate non-essential things for which available data cannot resolve. Often this is used to destroy the credibility of data that would answer critical questions. It is always possible to bash data sources. You can ask millions of questions about a given source for which you can't easily resolve with other sensible data. For example, climate gas lighters love to engage people in questions about statistical adjustments to raw data. This gets most people way out of their depth in a hurry. What is sensible data cleaning and structuring to disciplined scientist doing the adjustments becomes and endless litany about "what about this issue, what about that," which just confuses and bewilders the propagandist's target. All this is wastes time, raises needless doubt, and distracts from the more important issues. It can also get the target to disbelieve the data and adopt a cynical attitude towards the scientists who produce or use the data.
But here's the thing. All data is crap. It's messy, incomplete, not fully representative. We don't make progress by dismissing data because it is messy or wishing we had better data. How we make progress is to look for consistency across lots of crappy data, especially from different sources. That is, we look for the reliable trends that can be corroborated by different lines of inquiry and different sources of data.
So please, don't get hung up on IFR or CFR. Let academics publish papers on that years from now. That should not be our focus in the present moment. What are the big trends we should be paying attention to? Stay focused on that. You'll nice that kind of charts I like to post. These usually represent what I think are the big, reliable trends that the data are actually telling us. It important to actually look at the observable data. If you are curious about death rates, I'd recommend focusing on death growth rates. This is a fast-moving, dynamic process. IFR is a non-observable end state, who cares? Actual deaths are happing right now, let's see how this is unfolding so we can make sensible choices along the way. Also if you are worried about data issues in counting Covid19 related deaths, know that these data are coming form different countries and local jurisdictions. So the methodologies, issues and biases are all over the place. That's not the issue. When we see similar dynamics emerge from different data sources, we know that we are getting a robust picture of what Covid19 can do. So don't badger the data; compare results from different data sources instead.
We need to keep our heads up and eyes open. Avoid getting lost in things that cannot be seen at this point in time.
