Trying to understand the models behind the policymaking in times of #coronavirus, motivated by a rich discussion in the #CSOG mailing list & an ‘interesting’ chat w/ @JoMicheII.

I’ve started w/ this brilliant post by @complexcase – ht @jana_bacevic 1/n https://sacswebsite.blogspot.com/2020/03/modelling-coronavirus-why-all-public_19.html

1. Many public health models “fail to model human interactions and the complex networks in which we live” or “how populations react to the policies being implemented to help them” 2/n

2. Many public health models “are country-specific; that is, they fail to see their society and population as part of a wider and highly complex global system”, ignoring “major transportation routes”, for example. 3/n

3/. As consequences, these public health models “misunderstand collective psychology and how quickly ‘panic’ or ‘rebellion’ can set in” – e.g., “people failing to follow health behaviours guidelines; or how culture impacts health practices” (Italy versus Singapore) 4/n

4. More consequences, these public health models “fail to forecast the *knock-on* effects of their policies, for example: “how social isolation impacts different segments of the population differently” 5/n

5. Many models “don't think about disease transmissions from a *case-based configurational perspective*” (you have to read the blog). Therefore, they “struggle to demonstrate the differential impact that the spread of COVID-19 will have on different populations and subgroups” 6/n

6. On the data front, like many other models, public health model “lack good data”... “particularly the absence of current human immunity and also no current vaccines” 7/n

7. Another data problem. In public health models, it is not clear "what the *reproduction number* (Ro) should be - which is defined as how many people each infected person can infect if the transmission of the virus isn't hampered by quarantines, face masks, or other factors” 8/n

8. More (major) data problem. Public health models do not know the “COVID-19's incubation time, which is how long it takes for the virus to cause symptoms” 9/n

9. A final major issue, what is the question we are asking? "Is the goal to eradicate or manage COVID-19? We’ve been trying to stop the virus in the short term, but “what happens, though, when a country tries to go back to normal? Will the virus return?" 10/n

To sum up, some models are better than others, but "no matter how incredible the model, it is somehow or in some way wrong ... All models are underdetermined by their evidence. As such, we always need to be sober in our usage of scientific and public health modelling" 10/10

cc @ingridharvold @ingridharvold