ON the route out of lockdown, it appears that Nicola Sturgeon might be banking on the adage that "slow and steady wins the race".

As she outlined a staged approach to Phase 2 that has delayed any change to physical distancing for now and kicked the re-opening of beer gardens into the long grass, the First Minister told MSPs that "patience could reap our greatest rewards".

"The prize for going more slowly now is a recovery that is much more sustainable and one that will, I hope, allow more normality to return to our daily lives," said Ms Sturgeon.

READ MORE: A guide to some of Scotland's best beer gardens 

Since the UK began moving out of lockdown, Scotland has generally moved at a slightly slower pace: overall, we spent longer under lockdown, our schools remain closed, and non-essential shops will have to wait two weeks longer than England's to re-open.

One potentially interesting trend has emerged already.

For most of May, both Scotland and England were reporting roughly the same Covid death rate per day: in both countries it tracked steadily downwards from seven per million population around May 8 to around four per million by the end of May.

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Since then, however, the trajectory has split, with Scotland declining faster to fewer than one Covid death per day for every million people, while England's is around three per million.

How much that is down to the social distancing measures in place, or simply the population's compliance with them (this period overlaps with the Dominic Cummings controversy which some public health experts said risked eroding the public's cooperation) is impossible to say.

But it appears that the goal for Ms Sturgeon is not just to suppress the virus but to get as close as possible to eradicating it.

Stringent social distancing, contact tracing and quarantining snuffed out SARS 16 years ago. New Zealand has achieved much the same with Covid: it had had no new cases at all for 24 days, until two UK visitors tested positive this week.

The lower the prevalence of the virus within the population, the easier it is to pinpoint and contain new clusters, prevent a second wave and allow a fuller return to normality (again, see New Zealand) albeit at a later date.

Whatever our progress, Scotland recorded 992 new cases between May 28 and June 14, so eradication is still elusive.

READ MORE: Why 'the science' has no clear-cut answers to Scotland's two-metre dilemma 

In this context, the decision not to re-open beer gardens is all about a better result later: for example, reducing virus prevalence enough that physical distancing can be halved to one metre in time for the hospitality trade (including pubs) resuming on July 15.

Ms Sturgeon said there is emerging evidence that pubs, restaurants and gyms are "hotspots for transmission". Japanese research found that the risk of infection is around 19 times higher indoors than outdoors.

So why is it safe to open outdoor food markets but not beer gardens? One theory is that people in beer gardens spend a prolonged period in same company, increasing the risk of transmission if someone in the group is infected but not yet showing symptoms.

They are also more likely to talk loudly, shout, or even sing (after a few long-awaited pints) which is also linked to transmission.

Beyond one metre of an infected person, the risk of infection is an estimated 3%; within one metre, 13%. Modelling in the Lancet also suggested that the for every extra metre further away, up to three metres, the risk of infection or transmission may halve.

But the less virus in the population as a whole, the less relevance that risk differential holds.