Fun exercise: imagine a SecState or NSC Advisor referring to “studies” — i.e., the literature — as much as Yellen has in Cong. testimony.
This is partly a problem of “senior policy officials don’t read research”, or even try to keep up through staffers.
Also at issue is that an immense amount of what the best political scientists are doing is irrelevant to what State or the NSC does, and what is relevant is often of mediocre quality. I think this is improving but I’m not very sure.