It sort of does; the justices' law clerks do this kind of research, often digging up data or analysis to cite in support of an opinion's claimed policy effects

It sort of does; the justices' law clerks do this kind of research, often digging up data or analysis to cite in support of an opinion's claimed policy effects (not all of these references come directly from amicus briefs). I believe this is particularly common when a justice wants to refute a claim in an opinion on the other side; they'll instruct their law clerks to research the claim and see if it's really solid, or if it can be undermined.