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Re: [Phys-L] Ex: Re: modeling is easier than predicting

On Apr 7, 2020, at 2:03 AM, John Denker wrote a bunch of stuff I mostly agree with:

It is a tremendous fallacy to imagine that people will act
rationally. If people were even halfway rational, we would
not be where we are now.

It is also a mistake to model each state's long-term pandemic
response on a state-by-state basis, as if it were independent
of the other states. Short term maybe; long term no. For
example, suppose California stops the spread within its own
borders. This is doable, indeed likely, in the short term.
*) Longer term, things get ugly:

-- California could try to maintain the lockdown long-term,
but this would be economically unsustainable.

-- It could lift the lockdown, and suffer re-infection coming
in from other states, which vitiates the short-term success.;;sdata=tNVrXAZzAsrPvZqVoagfiOy7WDSCBaYbyVpqqCo9J0k%3D&amp;reserved=0<;data=02|01||9817d437bd1a4ce013e208d7dad2812a|164ba61e39ec4f5d89ffaa1f00a521b4|0|0|637218469973279328&amp;sdata=tNVrXAZzAsrPvZqVoagfiOy7WDSCBaYbyVpqqCo9J0k=&amp;reserved=0>

-- It could hope that other states get their act together.
Alas, as the saying goes, hope is not a strategy, much
less a pathway.

-- It could implement measures that control the disease
but are not as crude, clumsy, and costly as a lockdown.
Such measures require a multi-step process. So far
*none* of the steps have been implemented properly in
the US.

Just a few things:

1) I don’t think that reinfection from other states is likely to be much of a problem simply because we won’t be able to get back to NO infections anywhere until there is some kind of effective medical intervention. e.g. a vaccine, that confers a new, sub-unity value of R_o to COVID-19 everywhere. Until then there is simply no "getting back to normal” anywhere in the world. The problem isn’t having a few infections around; its allowing those infections to explode with a 2 or 3 day doubling time.

2) The R_o values in most of the trump states are likely to be low enough that they simply CAN'T generate the kind of explosive growth seen in New York or even California. Even a little mitigation there will go a long way. That’s a good thing from the standpoint of national health and a bad thing politically. It will enable lots of science denial, invoking of benevolent hairy thunderers, and voting for pathologically lying, lifelong conmen, malignant narcissists, and gleefully divisive sociopaths.

3) I heartily second JD’s touting of Pueyo's fine article. Indeed, I had hit upon the same “until there is a vaccine” solution myself after building and playing with my first COVID-19 simulation (the latest version of which is available here: on March 19, the day Pueyo’s article appeared.

4) Building on and refining the "hammer and dance” scenario … It seems to me that once we get things back to a one to ten deaths (50 to 500 infections) per day routine, we can reopen large parts of the economy with a heightened awareness of the deadliness of our hands, the stupidity of touching other people for any reason, etc. Doing so should keep doubling times below 4 or 5 days and prevent any local outbreak from exploding. Moreover, when a local outbreak occurs, there are lots of things we can do LOCALLY to address that without inconveniencing the rest of the nation. And eventually there will be a medical intervention.

Then we can get busy dealing with the Great Depression of the 2020s and being hopeful that this one will lead to something that at least vaguely resembles the massive social, political, and economic changes that led to the flowering of America in the 40s and 50s.

John Mallinckrodt
Cal Poly Pomona