How effective was the lockdown?
It is clear that there is contradictory evidence on the effectiveness of
the lockdown strategy. In the UK it is hard to be sure of the scale of
benefits: they range from very few lives saved to a high of perhaps
450,000 lives saved (that is the difference between the 500,000 or so
deaths projected by Ferguson et al (2020) (1) on the basis of no change
in behaviour and the 50,000 or so deaths that might have resulted in the
UK by early June 2020). Figures for lives saved in the UK at either end of that spectrum (near zero or as high as 450,000) seem implausible.
There are reasons to be sceptical of figures at the high end of that
scale which puts the saving of lives from the lockdown at several
hundreds of thousands:
- the low cost of effective forms of behavioural change (washing hands,
avoiding crowds) adopted by individuals makes it rather unlikely that in the
UK there would have seen 500,000 deaths even with no government
restrictions; the 500,000 figure from Ferguson et al (2020) (1) was
based on an assumption of no change in individual behaviour.
- the evidence of a turn in the curve before lockdowns are likely to
have had much effect is disputed but not easily dismissed.
- even if lockdowns stopped such huge numbers of deaths over the period
March-June 2020 they have not permanently stopped them happeningif wider immunity has not significantly risen so that any
substantial easing of restrictions will just bring them back.
- in many countries deaths were concentrated in care homes for the
elderly and have been disproportionately among older people so a
blanket lockdown (“don’t leave home”) may have been inefficient –
it generated huge costs (see below) and may have yielded limited
health benefits, over and above what might have been achieved with
measures which focused on groups most at risk.