Being honest for most people its not really a classically economically rational decision to have kids or not. "Hmm, in 20 years time, would I rather spend that money on university fees, or on a cruise..."

To add to what has been said above, it is huge fun. Of course its a commitment and a responsibility but taking on commitment and responsibility is what being an adult is about. Speaking personnally, I didn't even realise a part of my life was missing until I had kids and suddenly, there it was. Sure, now we have to take holidays on steam railways and beaches (not really my thing) instead of flying off to Peru, but their fun is my fun.

And for a jaded cynic like me seeing the word through the eyes of a two year old is very illuminating. When was the last time YOU got excited because you did a pee in the toilet? (A long time ago I hope and trust)

Also I now feel part of something bigger, in a way that is hard to describe. You feel closer to all the people who have lived before and all the people who will come after, and see yourself as just a link in the chain not as the summit of human existence.

But then again, if you don't want em. don't have em. Its not compulsory after all.