“I wish to be left alone,” said Scrooge. “Since you ask me what I wish, gentlemen, that is my answer. I don’t make merry myself at Christmas and I can’t afford to make idle people merry. I help to support the establishments I have mentioned: they cost enough: and those who are badly off must go there.”
“Many can’t go there; and many would rather die.”
“If they would rather die,” said Scrooge, “they had better do it, and decrease the surplus population."
(The establishments Scrooge referred to were Prisons, Union Workhouses, The Treadmill and The Poor Law).
I'm a bit wary of the comments saying people who have decided that they cannot afford another child. In my experience this can mean anything from having a third would be a huge financial hardship to not being able to afford a third set of private school fees without giving up some other luxury.
People's expectations of how much children need to cost varies wildly.
2.1 may be replacement rate, but as there are people who stop at 0, 1 & 2 by choice or through circumstances, it isn't unreasonable to make sure we are providing a reasonable safety net to families who have the temerity to have 3 or more kids before being made redundant or having a disabling accident. An average of 2.1 doesn't mean we don't need families with 3+.
Birthrates are falling precipitously worldwide.