Joshua Gans on The True Cost of Parenting, and why $180,000 may not necessarily be as outlandish as it sounds especially when the opportunity cost of stay at home parenting is factored in:

Parents know their children, have their interests at heart, are on call all the time and mean you don’t have to worry about child care.  This is precisely the utilitarian services that the high priced nannies are being valued for. Once you include stay-at-home parents, you’ll find that we are all paying much more for nannies than we think.

The original article on the $180k nanny here.