A coworker keeps telling me (I'm a parent of one, and intend to stay that way) that having a big family like his is easier, since the older kids can take care of the younger kids.
Which sounds totally plausible and correct, 'cept it'll take you awhile to get up to that sort of economy of scale :P
This being Hacker News, we can talk about it in terms of graphs, right? Let's look at the sociogram when one parent is present.
The transition from zero to one is of course world-changing. But at one child, 100% of the connections in the sociogram connect to a given parent: zero economy of scale.
At two children they have each other, but that is only 1/3 of the children's connections when one parent is present.
At three, we're up to 50% of the connections that are child-to-child. At this point the sociogram is rich enough to become interesting.
> At this point the sociogram is rich enough to become interesting.
But the family is poor enough to become boring!
(I can't resist a good pun.)
Anyway, kids aren't raised in isolation with their parents. Our two year old tot already has two kids that I would consider her friends; she mentions them when she's home, and she prefers spending time with them to spending time with other kids.
Ask any member of a large, poor family whether they would trade (life improvement costing $XX,XXX) for having fewer children in the family. Life is beautiful and easily beats filthy lucre. It's worth the struggle. People lose sight of this.
I spot two assumptions in your comment: 1) that families plan the number of children they have, and 2) that this planned number is some number lower than 16.
Yours is not the only worldview.
And with birth rates plunging worldwide, many now trending below sustainable levels, who will provide you with healthcare and other services in old age?
It can be done that way, but there are alternatives. One family I know, the kids actually sometimes quarrel to be allowed to take care of the youngers. In our family, we have "chore points" that are mutually negotiated, and babysitting is a favorite way to get one's points racked up easily.
Which sounds totally plausible and correct, 'cept it'll take you awhile to get up to that sort of economy of scale :P