"Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.'This wasn't a new idea, it has been applied to planning theory since at least the 1950s. It is distilled in the idea of "the fog of war" where decisions are made on the information you have while clearly understanding that the situation is in flux and any decision may be wrong because there are thing you don't know and you know you don't know them. If we could interview the Japanese Admiral at the Battle of Midway, he would have some insight into the nature of this problem.
Unknown unknowns are just that. I don't know what they are, neither does anyone else.They are impossible to account for.
Known unknowns are easier to identify, allow for data gathering and planning, and sometimes reveal unknown unknowns in the process. Here are some of the known unknowns in the current Covid19 pandemic and the response.
1. Percentages of infected persons in various populations, city, suburban, and rural.
2. Lacking good data on #1, percentages of infected that become seriously ill.
3. Lacking good data on #1, percentages of infected that die.
4. Effective treatments for infected to mitigate the effects of the disease.
5. Effectiveness of current social distancing in halting or slowing spread of the disease.
6. Is it possible to create a vaccine.
7. Effectiveness of a possible vaccine.
8. Do humans develop an immunity after exposure and recovery.
9. Will natural viral mutation result in repeated waves of disease in the future.
10. Will it be possible to restart the economy.
11. What are the long term effects of the shutdown on the country.
12. Lacking good data on #1 and #5, when is the right time and what is the timeline to restart the economy.
There are others, one through twelve I came up with. Put yours in the comments. I will edit the post and add to the list.
Update 4/23/20: Here's additional input from the comments, thanks to everyone who contributed. If I paraphrased your input and you feel it was incorrect, please comment again with your specific input in consise form and I will revisit this again.
13. What will signal that it's time to return to business as usual (Libertyman)
14. Edit unknown #1 for more detail. Percentages by age groups as well (Tim Wolter)
15. Effectiveness of available treatments and when in the disease course are the treatments most effective (Old NFO)
16. How many people with other diseases will die because hospitals stopped treating all other diseases and shutdown all non virus wards to other surgeries and treatments (HMS Defiant)
17. How many healthcare systems will be impacted by the loss, critical loss of doctors and nurses to both death from virus infection and a decision to call it quits to the practice of medicine and long term availability rates of hospitals shut down by loss of staffing (HMS Defiant)
18. How many healthcare systems will simply close down once the virus goes into reduction only to be needed next winter as the 'new influenza type killer corona virus roars back to life just like the flu does every year (HMS Defiant)
19. Corollaries to #2 and #3 need to account for comorbidities, e.g. those who died because of the virus, and those who died with the virus (Eagle)
20. What are the significant comorbidities, how significant, do they overlap (Eck!)
21. What are secondary effects on the social order, focusing on oil, oil storage, and production (Differ)
22. What is the cost in lives of reopening the economy (Aesop)
23. What is the cost in lives if we remain shut down (Phelps)
24. How would we achieve herd immunity (ADS)