Put some keywords into Google Scholar and you will find heaps of research on this topic. Here’s the first one I found. https://link.springer.com/article/10.1057/eej.2014.22

> We estimate several models with an extensive list of control variables and high school fixed effects. Results consistently show that high school GPA is a positive and statistically significant predictor of educational attainment and earnings in adulthood. Moreover, the coefficient estimates are large and economically important for each gender.

GPA should be a result of mastering the material. Assuming that is roughly the case, if you ever go on to use any of the skills you were supposed to learn in school (math, computing, etc) you are asking if having learned those skills would help you perform those skills?

I doubt there will ever be a way to satisfactorily control for other variables when it comes to these sorts of real-life studies (there is a reason the majority of social science isn't reproducible[1])

[1] https://advances.sciencemag.org/content/7/21/eabd1705

>GPA should be a result of mastering the material.

I know that personally my grades don't tend to correlate with my actual knowledge at all. I've failed things because I've been bored with them, and I've gotten perfect grades on things I don't understand at all outside the tested material.

Same, I think this is the assumption that doesn't always hold up. However, it often does, and how well it does depends on the teachers and school.

So the answer is no.

I would lean more towards this is one of those truths that can be taken as self-evident. But, at the same time I would be skeptical that any published evidence would account for the infinitude of confounding factors.

My guess is it is similar to IQ results - does a good job weeding out people who know nothing, but does worse differentiating between students who are satisfactory and those who are exceptional

AFAIK there's more evidence supporting that ~B students are the most successful vs A students.

Who cares? You're dealing with millions of school kids every year, and need aggregatable data to make important policy decisions about how education is done. As long as it correlates well, it's easy to collect, and can be trusted not to be manipulated for bad incentives like this article implies is happening, we use it.

OK, where's the data?