In the modern era many of us actually decide whether or not to have kids, as opposed to just having them. We way the pros and cons. We think about the costs of raising kids, the time commitment, and possibly moving to a better school district. And of course we think about raising kids with the knowledge a global war over water and food supplies will probably occur in our offspring's life time.
It's this last question that is not as clear cut as the first three-- either you have the money or you don't, same with time, and do you really want to live in Greenwhich, Ct? But the inevitable war is more complicated. Do you want to have a child just to watch him/her die in a ruthless anarchistic war between the haves and have nots? Or do you have the kids knowing that by the time the war comes you will be old and somewhat feeble and need your youthful children to protect you or seize water and food for you? Then of course you have to consider will the conditions be so bad that your children won't help you. That helping you would compromise their own survival. How heart broken would you be to watch your own children betray you after you moved to boring ass Greenwhich, CT for them. Are those the type of ethics they teach up in that public school system? Nevermind that fact that you are going to starve to death or be eaten alive by crazy cannibals, hopefully those cannibals won't be your own children.
So do you have children and take the chance they'll leave you to die and all that money and time spent on them will have been for naught? Or do you just enjoy yourself now and start stockpiling water and weapons? Or do you first take psychology classes to learn how to successfully manipulate your children so that they will fight to death for your survival?
It is a tough question to answer. Similar to whether or not one should go to grad school.