much lower than for male. therefore, for a successful male to find a successful female is much more difficult than for a successful female to find a successful male.
men are supposed to be intelligent animals, they are also greedy, vain, and with too much pride. thinking with their toes, they'd rather pick a brainless pretty face, since it is so much easier than finding a successful woman and the sunk cost is so much lower -- only cost you some unexpected gifts at unexpected time.
plus, what is the % of successful men marrying successful women, out of all the successful male population? u haven't seen the whole world yet. so zip it!