Laird has been so kind as to proofread it. The latest draft (#5) is on OSF now along with the new source code etc.
The new draft has a new section re. the size of the GPA gaps, which includes both calculations on a country-level and at the total immigrant population level by generation.
There are some language issues. For example:
"A large body of research shows that immigrant performance and traits are predictable from their or their parents’ countries of origin."
What you mean is e.g.,
"A large body of research shows that the traits of immigrant groups can often be predicted from the traits of the inhabitants of their (or their ancestors') country or region of origin."
"Since g is not the only factor that causes differences in g, one would not expect a g difference of 1.0 d to be associated with a 1.0 d difference in GPA. I could not find a study that reports the correlation of IQ with GPA in the final exams in Denmark, but such a correlation would likely be around .5-.7. For the UK, the correlation of g/IQ with the similar GSCE exams has been reported as .58 and .69.[23, 24]"
In the US, GPA is grade point average which is based on more than exams; it is also based on homework and class participation. If Danish GPA is a similar construct, the correlation between it and IQ should be lower than what you suggest (at around 0.3 to 0.5, see appendix A here). Is Danish GPA like UK standardized tests (GCSE exams) or like US grade point averages? Please clarify in the paper.
What's up with footnote (3)?
Would you mind rerunning the correlations with native Danes excluded and letting me know if the results are similar. Immigrants (i.e., 1st and 2nd gen) often systematically perform differently than natives (i.e., a true immigrant effect), so there can be a immigrant x origin effect. I have found one before.