Public schooling was started to keep kids out of the workforce but that doesn't affect your premise

"There's plenty of data showing that time spent in school does not strongly correlate with learning,"

I have issues with your first source who I believe has seriously misrepresented the data, made accusations of bias without providing evidence, was carefully selective about sources, and has a self admitted bias. Let's get into some parts of his paper.

---------------- [The Author makes his points]

Section 2:
In the Benezet experiment, a school district taught no math at all before 6th grade (around age 10-11). Then in sixth grade, they started teaching math, and by the end of the year the students were just as good at math as traditionally-educated children with five years of preceding math education.

the author thinks this is related to the age of the student which I personally think is a heavily weighted variable in learning. However this only means that there is a limit to the amount of time lost (the kids caught up) and age is a factor

He then goes on to New Orleans in which they lost one to two years of school, went back, and outperformed their peers, but the author also notes that they switched to charter schools which (not shown in your reference) have a noticeable impact. So again, there's another variable besides time spent. [a]

Additional points - immigrants and homework (homework having no value i.e. homework is like being school and less homework doesn't hurt)). These do appear to be valid towards his theory

He then mentions home schooling - He shows that by the time kids get to college they have equaled their peers. The author says that home schooling isn't like school because some (I hope some meaningful amount) parent's aren't actually teaching their kids, only answering questions (his words something about unschool). If home schooling was like school then this would work against him because it's time in a school like environment and those kids matched their peers. He provides no evidence that a significant amount of parents are operating in a way that is unlike school. I assume the only way that would be valid was if the kids made the learning decisions themselves.

-----------------[Author talks about studies that worked against him]

I stopped reading after the intro to section 4 which I will now quote-

"The strongest counterevidence to my position comes from a body of literature on the effect of other long-term school closures, mostly from disasters but occasionally from teacher strikes.

I’m inherently skeptical of these, because I’m suspicious that education researchers love finding that education has huge effects, that any disruption to education is a disaster, and that kids should be in school much more. This is in addition to the usual bias for positive results. Still, the studies exist and we should look at them."

To be fair , as stated, he does start to look into them. However he had no issues with using studies from researches that worked for his theory but if they work against it then he's skeptical.

So let's get into his section 3 though where he tries to poke holes in the studies that work against him.

His response to counter studies 1 - The more snow days, the less learning - His counter is that in the study the only snow days that mattered were in late February and since they tested in March the kids were missing test prep.

My thoughts - Prior he never questioned or looked at when school loss happened as a variable and how it effects learning. Prepping for a test is still studying the material I don't think it's fair to now start digging into the time of the year when that happened to counter studies that work against him

He does offer a decent counter after this by citing a study in MA that didn't show less learning from snow days

His response to counter studies 2 - Teacher's striking leads to loss learning (US) - He says this in response " don’t entirely understand their methodology, so I can’t critique them very well, but I have to admit I’m skeptical of them anyway" Again he states he is skeptical for no other reason because he doesn't understand the methodology and it goes against him

His response to counter studies 2 Teacher's striking leads to loss learning (Argentina) - he says "I can’t find any specific problems with this study. It just seems extreme to me" he then basically accuses the study of being misleading because he doesn't understand it.

------------------------[My final thoughts]

I'm going to stop. Basically for your first reference the author didn't look into this with an open mind, admits his own biases (because I guess he's a hero for doing that), and then looks negatively upon studies because researches want to find positive results for schools but only if those researches results go against him, otherwise he accepts them

In my opinion this person had an agenda and made the data(studies) work for him. Admitting his own bias is fine but that's only a small part. It appears he hasn't overcome it.

[a] https://www.ncsl.org/research/education/charter-schools-rese...