I know this is tangential, but I want to point out why the statistic you used is deceptive.

Ah. Thanks for the correction.

At some point, more kids means higher prices (or, in a command economy, smaller rations) for everyone else.

At some point in the far future, yes. But for now, more kids are AFAIK considered to have positive externalities, and barring uploading or the Singularity that looks to be the case for at least a couple of hundred years.

(Of course, discussing developments a couple of hundred years in the future while making the assumption that we'll remain as basically biological seems kinda silly, but there you have it.)