While virtually all countries adopt the lockdown strategy to eliminate the virus spread, UK is apparently going on with 'herd immunity' strategy. It's pretty well explained in this tweet:
https://twitter.com/iandonald_psych/status/12385183716516495...Basically, the idea is to get the young infected, as the virus seems to be relatively inoffensive for young people, and thus becoming immune. Once the country reach a threshold percentage of immune population, the virus cannot spread effectively anymore, hence protecting the vulnerable ones.
My gut feeling is that this is the rational thing to do, however only in theory. In practice, people won't be disciplined about isolating vulnerable ones in the first phase, thus leading to disaster.
While that may be technically right (under some optimistic, unverified assumptions, e.g. no reinfection), it's a false dichotomy. Singapore, Hong Kong, and South Korea aren't under lockdown, they're stopping the spread by just having good testing and case tracking capacity, and good hygiene. And the longer things go on, the better they're getting at doing that. If things are getting out of hand, a temporary lockdown is effective (as it was in China), to get the numbers down while building up this kind of capacity. But lockdown doesn't have to last forever; China has already lifted restrictions in most cities.
The UK seems to be ignoring this, and I don't understand why. I suspect the real logic, as some government officials have outright said, is that a completely failed response would free up money for the NHS by killing off "bed blockers".
The social signalling around it is "prudent caution", in the sense that they are talking slowly and confidently while using big words. This gives some people the gut feeling that this must be the "rational" thing to do, but it's just window dressing. The plan is neither prudent nor cautious; it's recklessly endangering millions of lives. Experts in the UK are horrified; there's an hours-old petition against this with hundreds of academics already signed on [0]. The WHO has condemned it, and half the people I know studying abroad in the UK have fled the country over it.
0: http://maths.qmul.ac.uk/~vnicosia/UK_scientists_statement_on...