Private market fans are usually a fan of private education. The trouble is that educational outcomes are mostly just genetics, so there isn't much room for improvement. One way to study this is to look at school voucher randomized trials.
This meta-analysis shows that they don't do anything for reading or math ability in the West. The results for non-Western countries are larger, but not very trustworthy due to rampant scientific misconduct in those countries. Shrug tier.
Private education probably preferable on other grounds, but not for actual learning outcomes.
The Participant Effects of Private School Vouchers Across the Globe: A Meta-Analytic and Systematic Review
Americans are super fat, so many people look for explanations for this, usually something USA-specific like seed oils, or corn syrup.
Americans have some race differences too, but they aren't that large. The White Americans are quite fat by themselves, only Asians drag the mean down.
Maybe it's due to money. Americans are rich. Yes, but the plot worldwide looks like this. There's just about no relationship between median income (or GDPpc) after covering basic necessities.
Can Europe learn from Ghana? Buried on Wikipedia is a 3 sentence part about how Ghana deported 20% of the population -- 3 million people -- all the non-Ghanans. And it only took 3 months. The "Ghana Aliens Compliance Order" (GACO)
This website provides the history. It begins, of course, with economic migration since Ghana was the gold coast. In fact, these migrants were going into a British colony, probably for the usual reasons of wanting to live under European domain: rule of lawand prosperity.
European rule eventually declined, and just after they left (1957), the economy goes bad. At least, so they say, but it doesn't look that way until 1970s by GDP stats.
In Germany, non-German students (anyone with "migration background") get lower grades and test scores.
Due to their politics, teachers are expected to have some bias towards girls, minorities, low-SES etc. students. So do they? The authors find that, yes, they do.
New Dutch results on immigration. Sobering as usual. There are 3.7 million foreigners in the Netherlands.
One can calculate a given person's contribution to the state budget by adding up all their contributions (revenue) and subtracting all of their costs. Doing so gives a net contribution metric. Dutch people are c. net 0, and the others groups net negatives.
There's a lot of variation though. Numbers for the first generation can be very positive or negative. It's easier to get very positive values because many people arrive after having finished their education, so begin working immediately. Many of them leave before pension too.