Executive summary

  • We compare the economic costs of containing the Auckland August outbreak of COVID-19 using Alert Level 3 to those that might have been incurred from the use of Alert Level 4.
  • We estimate the effectiveness of Alert Level 3 using data from the actual August outbreak. The effectiveness of a putative regional Alert Level 4 is less certain, but we consider an optimistic estimate based on what was achieved in the March-April outbreak, as well as a more pessimistic estimate, which reflects the higher transmission rates observed in August.
  • We use a decision-making model for de-escalation of alert levels based on observations of weekly case numbers, which is a simpler decision-making criterion to that used in New Zealand and likely underestimates the duration of Alert Level 4 periods that would be used in practise. To achieve the same likelihood of elimination, we find that both the optimistic and pessimistic Alert Level 4 period has a shorter duration than the period needed at Level 3.
  • To achieve the same likelihood of elimination, the optimistic Alert Level 4 controls have a lower economic cost than the Alert Level 3 controls.
  • To achieve the same likelihood of elimination, the pessimistic Alert Level 4 controls come at a comparable economic cost to the Alert Level 3 controls.
  • This analysis does not take into account the longer term economic costs of these measures, nor does it consider social, or health impacts that might differ between strategies.