Here are some comments I’ve written in a rapid response to Brendan Murphy’s recent press conference. (I haven’t yet seen even the summary of the modelling that has apparently been released, just a picture of flattened curves.)
The idea of “flattening the curve” is fundamentally misleading, since it implies that most people will be infected until herd immunity is achieved, while the number of cases remains within the capacity of the health system. But assuming spare capacity of 2 beds per 1000 people, and 20 per cent of patients requiring treatment, we would need at least five years for herd immunity to be achieved. Optimal policy is to aim for near-complete eradication, then maintain sufficient distancing to ensure local outbreaks don’t spread. We will need quarantine for international arrivals until vaccination is general, or until other countries achieve near-complete eradication.
The main insight from economics is derived from option value concept. Better to adopt stringent measures early and relax if they turn out to be excessive than to move slowly and risk widespread community transmission.