Here's a link to a FAQ about company hiring procedures that includes a reference to the Schmidt and Hunter paper, along with more recent literature.
https://news.ycombinator.com/item?id=4613543 Note that because most companies do NOT hire on the basis of IQ (especially so in the United States), it is often not the case that the highest-paid persons are the smartest persons, even in the same company and the same job classification. There are definite individual advantages to having higher rather than lower IQ, and the secular increase in IQ scores over the last century
http://www.psychometrics.cam.ac.uk/news.13.htm has probably been good for all the countries that have enjoyed it, but that's not at all to say that IQ cannot be swamped by other factors in setting the income of particular families, especially the younger members of those families whose well being is influenced by the choices of their elders.
