Yeah, it could be a cause of them having few or no symptoms making them less likely to fall into pillar 1 and pillar 2 testing. But if you accept the premise that they have fewer symptoms, then that's another reason why kids spread it less: asymptomatic people can spread it, but much less often. Symptoms don't play a role in the random sample swab study ran by the ONS, though. And it has consistently shown young kids are infected much less frequently than young adults, and that young kids have consistently tested positive less often than someone my age, even while the majority of us are not going into work every day while they go into school every day.
I'm not picking and choosing evidence nor epidemiologists. That's a weird case of projection. I used the evidence you provided on Northern Ireland, just like I used the evidence @F-Red provided from PHE, and in both cases I outlined the weaknesses in the data that could lead to the wrong conclusion while using that data to make a point. I've spent a lot of these discussions just assessing the evidence, never dismissing it. I have never said "well one expert says this and the other expert says this so really it's all about opinions, right?". I believe it's important to consider all of the evidence and evaluate it on its strengths and weaknesses, with the objective of better understanding the situation, while you use it as a tool to prove a point. So let's break down those two claims seperately.
Yes I think a reduction of 0.2 is significant for masks. I also think a reduction of 0.2 for schools is significant too. If you actually asked people what they thought rather than using them as a prop to tell other people why they're stupid, you might run into this confusion less often. As laid out in NI's documents, it's not just about the impact it has on reducing transmission, but also the economic, social and psychological impacts. This is their assessment of school closures:
Alternatively they assess the impact of closing classes when cases pop up - the method they're going back to now - as "low". They also assess the impact of wearing masks as "low", regardless of whether it's indoors or outdoors.
That's quite a big distinction to start with. Wearing masks hurts basically nobody, but it reduces the impact of transmission signficantly. Closing schools hurts a shitload of people, but it reduces the impact of transmission significantly. How significantly does it have to reduce transmission for those other harms to be worthwhile? That isn't self-evident.
Personally, I think if they believe closing schools could reduce the R rate by as much as 0.5, they should close schools. The problem is, they've said themselves they have low confidence in that assessment, and have outlined the fundamental issue which is they don't know how infectious kids are. For whatever reason you keep skipping past that main point, you choose to believe these scientific advisers about one thing, but not the other. I choose to believe them about all of these things, while recognising the level of uncertainty that comes with their assessments that they themselves state over and over again.
Irrespective of my opinion, I don't think people are stupid for thinking that schools should stay open even if it did reduce the R rate by 0.5. It's a very complicated problem. The evidence you provided outlines the harm it will do, and they have high confidence in that assessment.
Secondly, the claim the epidemiologist made is completely consistent with the other scientific evidence provided. First he specifies secondary schools, not primary schools, and second he points out the need for some restrictions. No-one is saying that if you have secondary schools completely open with no measures that it will have no impact on transmission. Every country has applied some measures because they (and the scientific community) agree that it does relatively little harm to apply these measures, while it does have an impact on transmission.
If he tightened that definition of "secondary schools" to "people 16+" then his argument would be right there in the middle of the scientific consensus, which is very different from what you, @Garethw, @golden_blunder or others have stated. They were talking about young kids specifically, you were talking about young kids inclusively. That epidemiologist is not, because he's looked at the evidence.
So let's be clear about the position stated. The evidence strongly suggests that primary schools are not hotspots for the virus, but leaving them open will have a small impact on transmission. The evidence is less clear on young teenagers, but they do get infected more often, so they are likely to spread it more often. The evidence is clearer on older teenagers, who get infected much more often than young kids, and they have led the surge in cases along with university age students.
Overall, closing schools would reduce the transmission rate. It probably wouldn't reduce the transmission rate enough for it to be worthwhile closing primary schools. It might not reduce the transmission rate enough among kids 10-15, and there is an open question about whether they're getting it in schools or bringing it into schools, and how much they pass it among each other. It definitely would reduce the transmission rate enough for it to be worthwhile closing school for 16-18 year olds, and even more so for uni students. But they're political decisions.
My argument to you or others has never been that we shouldn't close schools. I don't think closing schools is the catastrophe others do, and if it's a trade-off between this and many other restrictions, then the economic harm done to low-income parents in this jobs that are disproprortionately effected by restrictions might well do more harm to their kids than closing the schools. If they don't have food to eat they don't learn. So at the very least I think cloing schools should be on the table. But it isn't a silver bullet, nor an explanation for us being where we are now.
What I've been arguing against is your explanation for why we should close schools. The notion that it's obvious young kids going back to school is the driver of this trend...it's not obvious, and if you test that theory in a number of contexts, a number of flaws pop up. We shouldn't be making these kinds of decisions or having these kinds of discussions on misrepresentation of the data, or dismissal of the best available evidence, just because anyone that doesn't think your way is an idiot. That's dangerous in many ways. So when you made arguments that said "the evidence says this" or "one epidemiologist says this, others say this, it's up to you who to believe", I thought it worth disputing those claims with actual evidence.