Tell me what it is you do for a living?
Pshycologist
This is reflected in the bell curves - women have less variation than men. This is why more boys are born than girls - more boys die because they tend to take chances growing up.
Birth rates are generally pretty close with less than a
What biological expense of child birth? Women live longer than men. If women incur a 'biological expense' death rates certainly don't support your argument.
http://www.time.com/time/health/article/0,8599,1827162,00.html
Please provide data confirming that women are risk adverse more so than men. Your bell curve argument is hack science and you argument(s) over all are weak. Your 'business requires the ability to take risk and so men are better at it' is long bow to draw as well. Australians richest woman (and one of the richest people in the world) is a woman, same for the PM, same for an ex New Zealand PM and the list goes on.
No amount of careful planning will ever replace dumb luck.