over ten years ago I read that, in the countries that have liberal time off for paternity/sick child leave--full pay for 6 months, IIRC--only 1.5-2% of all men took advantage of them. i'm sure the number has increased since then, but I doubt by much.
about 5 years ago, research showed that, among professionals like lawyers and upper mangerial execs, men who had wives who stayed home made quite a bit more than counterparts whose wives had careers. that was due to a combination of men not asking for raises b/c of two income, of employers' not being as generous, and because men whose wives stayed home made it possible for them to work 70 etc hours a week and get lots of face time, which correlates highly with advancement on the corporate ladder.
kelley