The net might be less than the cost of a nanny at first, but kids do not need nannies, generally, when they go to school. If the spouse choosing to stay at home

The net might be less than the cost of a nanny at first, but kids do not need nannies, generally, when they go to school. If the spouse choosing to stay at home would prefer not to set their career back the 5-8 years (depending on how many kids) then that would still be worth it in the long run, salary wise.