Introduction
In early March 2020, it seemed that the COVID-19 virus in the United Kingdom was spreading exponentially with no clear sign of imminent slowing; the fatality rate was unknown and the ability of the National Health Service (NHS) to deal with rapidly rising numbers of seriously ill people was unclear. Estimates made at that time put the likely level of UK deaths if there was no change in behaviour at 500,000 (1). Based on that, and other, assessments the UK government followed the example of several other European countries in introducing severe restrictions on individual movement. The key message was to stay at home; this was a lockdown. That served both to slow the spread of the virus and to signal in a very clear way that people needed to quickly change behaviours, but it also generated great costs. The extent to which the lockdown contributed to a subsequent slowing in the rate of new infections and deaths is not clear. This paper summarises the evidence on this as part of a wider assessment of costs and benefits of severe restrictions – “lockdowns”. We do so to inform the decisions on how restrictions in the UK should be lifted.
While it is clear that the cost of the lockdown has been large, just how great it is will not be known for many years. This cost – as well as the benefits of lockdowns - should be measured in terms of human welfare in the form of length and quality of lives. Such measurement is profoundly difficult. Yet measurement of the costs of restrictions needs to be weighed against the benefits of different levels of restrictions to assess what is the best policy now. The cost of severe restrictions plausibly rises more than in proportion to the length of a lockdown. Two months of missed treatments for cancer, of company closures, of postponed screening for serious health conditions, of lessons missed at schools and universities, of many people living in very stressful situations is likely more than twice as bad as one month. In contrast, the benefits of maintaining a severe set of restrictions – the lockdown – may be diminishing as described in Bongaerts et al (2020) (2). Decisions on how to ease restrictions are therefore of immediate significance.
In this article, we aim to calibrate what the costs and benefits of severe restrictions might be and what that implies about the policy that should now be followed. We look at evidence from many countries, focusing particularly on European countries with similar levels of income and healthcare resources. We then draw out what this implies for policy in the UK.