I agree. Every other comment here seems to be like "well duh" and I'm... skeptical. My experience is that the ACT/SAT seem to be good indicators of getting good grades in well-defined spaces. But things like creativity, curiosity, work ethic are much better predictors of other kinds of success that frankly matter much more in the real world.
I know some really, really unintelligent people who got good grades in college. They just ate books.
Undergraduate GPA predicts lifetime earnings[1], incoming test scores and GPA are highly predictive of both advanced degrees (which increase earnings), and increased earnings within degrees [2], [3].
I suggest these effects are because being a good student aka "eating books" is correlated with conscientiousness. They show up to lectures, prepare, and test well.
And conscientiousness is very highly correlated with lifetime achievement, AND fufillment [4]. So measuring conscientiousness, and signalling high conscientiousness is a really good idea.
IQ is great, but conscientiousness is how you get things done [5]
That is...an extremely narrow study to use to make that broad an assertion. GPA of two classes from 2010 at a single business school in China, their starting salary, and then their salary in 2018?
Why is it narrow? N is a few hundred at a well ranked and good amount of rigor university, and is aimed at the graduating class and then their earnings as they rose through to probably mid career positions past entry level.
I haven't read the entire study mostly because I don't care, but I think you're wrong in your statements.
GPA is well correlated to earning potential, as well as earnings in reality.
Their Figure 1 is why we keep having these discussions in society. It's grossly misleading and not what a scatterplot for a 0.46 correlation looks like. I know what the figure is, it's just done in a way to overstate a case and ignore variability within bin.
If that figure were about anything else, people would be screaming bloody murder about misleading figures and overly generalized interpretation.
I'm in favor of allowing for the use of test scores but they get abused and the language in this report is a good example of how this happens. Scores have these real but modest correlations with real world situations, but then get used as rulers of atomic precision without any context or recognition of their massive limitations.
It makes the authors of this report look either deceiving or ignorant of statistics or both.
I know some really, really unintelligent people who got good grades in college. They just ate books.