Where we stand in Covid-19 lessons learned

Nowhere near the last word but an interesting analysis that is supportive of what I anticipate will become the mature assessment once the dust has settled.

From Four Stylized Facts About Covid-19 by Andrew Atkeson, Karen Kopecky, and Tao Zha.  From the Abstract:

We document four facts about the COVID-19 pandemic worldwide relevant for those studying the impact of non-pharmaceutical interventions (NPIs) on COVID-19 transmission. First: across all countries and U.S. states that we study, the growth rates of daily deaths from COVID-19 fell from a wide range of initially high levels to levels close to zero within 20-30 days after each region experienced 25 cumulative deaths. Second: after this initial period, growth rates of daily deaths have hovered around zero or below everywhere in the world. Third: the cross section standard deviation of growth rates of daily deaths across locations fell very rapidly in the first 10 days of the epidemic and has remained at a relatively low level since then. Fourth: when interpreted through a range of epidemiological models, these first three facts about the growth rate of COVID deaths imply that both the effective reproduction numbers and transmission rates of COVID-19 fell from widely dispersed initial levels and the effective reproduction number has hovered around one after the first 30 days of the epidemic virtually everywhere in the world. We argue that failing to account for these four stylized facts may result in overstating the importance of policy mandated NPIs for shaping the progression of this deadly pandemic.

 If I am interpreting correctly, in slightly plainer English:

1. There is a 20-30 day window after crossing a threshold of 25 deaths.  Once that threshold is crossed, there is a spike in the growth rate of deaths across the next 20-30 days.  Growth rates of Covid-19 start very high, around 3 and plunge to near zero by the close of the 30 day window.  
2. The transmission rate in deaths remains near one after the 30 day window.
3. The decline in the rate is due to a falling transmission rate rather than approaching herd immunity.
4. These characteristics are true in all locations.  Social distancing, mask wearing, commercial closures, etc. seem not to have any influence on the above facts. 
5. A second spike remains a real but incalculable possibility.  

Ultimately:

The existing literature has concluded that NPI policy and social distancing have been essential to reducing the spread of COVID-19 and the number of deaths due to this deadly pandemic. The stylized facts established in this paper challenge this conclusion. We argue that research going forward should account for these facts when assessing how important NPI policy is in shaping the progression of COVID-19.

We'll see.  We still don't know what is going on but I see a lot of research now trending towards a conclusion of this nature.  

• It is just another pandemic
• Non-pharmaceutical interventions have made little or no difference
• We should have stuck with the pre-pandemic planned strategies of little or no interventions
• Anti-viral treatments are still a ways off and likely will not have an impact on the course of the disease.
• Coercive NPIs probably had no impact on the disease progression but have caused excess economic damage with additional collateral health impacts.