It almost seems like our government is trying to engineer the second wave. If they really want people to come out and start spending money to kick start the economy, why don't they come out with strong firm regulations on masks and social distancing, so that people do so safely. Instead of, "Oh well if you feel like it." advice. Or are they still trying to hide possible damage to their image, caused when they ignored the advice of and the information coming from the W.H.O., to cover the fact that they were unable to organize the supply of enough masks. In other words, their image comes before public safety. I like this may make it a post.

The problem is that an Effective Reproduction Number would change drastically all the time. Basic Reproduction Number wouldn't really change (once it was accurately calculated). Anyway, the number of people in the pub, how close they sat, how segregated the groups/individuals stayed, the size of the groups, if they wore any type of PPE, what the temperature, humidity, airflow, and potentially UV light penetration was, if there was air filtration, if there was any natural or acquired immunity among the patrons and at what percent, the percent of initially infected individuals, etc. etc.

@JeffMurray This is good list of variables but it could be extended indefinitely. Humans I.e for social sciences generate the most varirables of all sciences

@Mcflewster True, I didn't think I did. The conclusion I was looking for from a reader wasn't, "Yup, Jeff named every variable" it was, "Yeah, Effective Reproduction numbers can't really be used as a risk assessment tool for individual areas."

@JeffMurray I take your point but what do we use? Boris seems to have abandoned explaining science to everyone. So thanks to some local councils local action has been taken quickly. If they get too heavy handed we can dispose of them within a year. How long will it take to dispose of Boris. He has had a year now and the longer he is there the more his influence will last even if he loses an election. Same for Trump.

@Mcflewster As sad as it is, you just have to assume every place is super contaminated and only enter/interact with places and people that are necessary. Additionally, you can get a sense of which places are higher risk by evaluating what people are going there. No one needs " to go to a pub, so pubs will generally have people that have been performing riskier behaviors (like being in rooms without masks with unmasked people they don't know), and thus, are more likely to have it. If you MUST go, try to stick to socially distanced patios with only people you live or work with all the time. You could possibly check social media to see if anyone is discussing whether or not staff members follow guidelines and enforce patrons following them as well. Around me, a lot of people post on Nextdoor about whether people follow the rules at local places.

@JeffMurray This is good advice and the approach that I follow. Just wish everyone would.