ZPG is the only ethical decision regarding the size of your brood.

It's not that simple. Smart, well-off people are more likely to not breed than stupid, poor people are. Which means that we're increasing the population with stupid people who are poorly raised. That's not good.

Any child I make is likely to be far, far better than average. And I'm likely to raise my kid better than average. So long as I don't have more kids than I can raise well, I'm improving the population by having and raising kids. And I can't stop the people who shouldn't be reproducing from reproducing.

Yes, adoption of very young 'uns by smart, well-off people also helps. And I intend to consider that. Although adopting is very difficult and dangerous, so until adoption becomes a better option, I don't blame people for not taking it more often. I'd probably consider adopting a child from another country, much simpler.

Oh, also, ZPG isn't just about how many kids you have, it's about when you have them. Remember, stop at 2 and start at 30 are considered equivalent. From that way of thinking, I'm already following ZPG no matter how many I have.

But if life expectancies are increasing, then stop at 2 and start at 30 may not even be ZPG... and it's not even reasonable to expect me to figure out what ZPG is.

However, stop having unwanted kids, stop having kids with no parent ready, willing, and eager to raise them and you'll solve a whole bunch of problems. So, people who don't truly want to have kids should stop it. Birth control and abortion need to become more common.

Ahhh, yes Patrick, the old "it's ethical for everyone *except for ME*" argument. I'm not sure if it's worth my time to pretend to respect that.

Could someone clue me in on ZPG?

It stands for Zero Population Growth.

Rachel's first response is good.  It's not that simple.

I know this is way late, but I would like to apologize to P for the nastiness directed at him in my comment, and for directing my comment at him alone, instead of him and R.