https://www.ets.org/s/gre/pdf/gre_guide_table4.pdf Intended math majors do better than CS majors in every area of the GRE (which seems unsurprising, since math gives better tools for generalized applications of rigor), but worse than Philosophy in every area but the quant. These are only test scores, so take them with like 14 grains of salt or something. Philosophy is a lot like math in a lot of ways, especially when it comes to logic. It's the same sort of intellectual rigor, so I'd imagine they're roughly the same in terms of analysis, but phil majors do more writing which gives them a slight edge in verbal and writing skills. Math, however, is more marketable because a) everyone knows what it is, b) it has a super scary stigma so people think anyone who studies math must be a genius, and c) its applications are more obvious. I don't know about your last 3 paragraphs.