Thread by @toxvaerd1

It now appears that infection numbers are worse than the “worst case scenario”. What does that mean and does this indicate a failure of the policies that the government has put in place?
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#EconTwitter #epitwitter
bbc.co.uk/news/health-54…

Let’s recall what the “reasonable worst case scenario” means. This is the outcome that epidemiologists think will occur when (i) people do not engage in ANY spontaneous behaviour change to protect themselves and (ii) government imposes NO restrictions on social interactions.
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In other words, it’s what one can predict based solely on biological considerations, knowledge of the disease, environmental factors, population density etc. It intentionally ignores behaviour and policy.
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Epidemiologists of course know that in practice, behaviour and policy will do some work to curb infection and don’t usually consider the worst case scenario as a reasonable prediction. Hence they use words like “scenarios” and “projections” bbc.com/news/amp/uk-54… 4/10

There is abundant evidence that spontaneous social distancing has taken place and severe restrictions have been imposed by the government across the country. So we’re not in the hypothetical world of the worst case scenario. This makes the numbers doubly troubling. 5/10

What this means is that the underlying disease dynamics may be worse than initially estimated. And this has straightforward policy implications that need to be seriously considered by government when making cost-benefit calculations. 6/10

This brings us back to the disease modellers and the scientific advice they give to policy makers. What to make of this situation? First, we’re continually learning more about the disease and with that, our ability to deal with it may improve. 7/10

Society is fiendishly complicated and complex and making predictions about social phenomena - or about natural phenomena that depend on them, like the disease - is notoriously difficult, something many economists have discovered over the years! 8/10

In addition, we should not ignore the role of randomness. However deep our knowledge of the disease or however sophisticated our models, some events happen by pure chance. They may be inherently unpredictable and so our inability to predict them is not a scientific failure. 9/10

All we can do, scientists and policy makers alike, is to be up-front about what we know and do not know and honestly communicate that, based on what evidence and understanding we currently have, specific policies have the greatest chance of having the desired impact. 10/10