Sadly each of these cases represents a real person, a real Italian. Our job is to help those fighting this disease understand better how it is behaving, and make intelligent moves to keep it from infecting (and killing) more Italians -- and everyone around the world.
Now let's get started....
Big picture:
Visit this Italian SIR model that includes death and real data. You'll need to "Clone Insight".
Hit Simulate. You should see something like this:
and you'll notice several things:
If you look at the flow equations from the "Infectious" stock, what are they? (report these in your word document)
These are predictions, which health care professionals and government officials may use. It would be nice if they were accurate!
Our objective: to modify the model to fit the data.
by making certain modifications and (dare I say) improvements on their model.
I'm going to have you reconstruct my model, which is pictured here:
So let's start with "what's new". I've added a "deathrate" and a "recoveryrate": I've short-circuited the process from the Infectious to the Dead and Recovered -- I'm not using the "Surviving Rate" anymore). I've also added the Infectious stock to the Total reported cases.
There are links from these new rates to the appropriate Flows, and from the Infectious to the "Total reported cases" variable.
There are also a few changes to things that you can't see, so I'll report them here; you should set up your model the same way, as follows:
Incubation rate: .025 R0: 3 First Lockdown: IfThenElse(Days() == 5, 16000000, 0) Total Lockdown: IfThenElse(Days() >= 7, 0.7,0)
(I didn't want to assume that the "Total Lockdown" wasn't leaky! So it gets successively tighter, but people are sloppy, so it simply goes to 0 exponentially, rather than completely all at once.)
As I noted earlier, these are modelled on lockdowns that the Italians actually implemented.
deathrate: .01 recoveryrate: .03 "Death flow": [deathrate]*[Infectious] "Recovery flow": [recoveryrate]*[Infectious] Total Reported Cases: [Dead]+[Surviving / Survived]+[Infectious]
I'll give you a couple examples of my own criticisms.
But an alternative would have been to make the Exposed do much of the infecting, while asymptomatic; and calling the infectious "Symptomatic" -- and hence quickly removed (yet still dangerous, and still infectious).