Somewhere around 1955 there were 150 million in the USA. Now there are 300 million. It does not appear there is any shortage of people.
Thanks in large part to immigration.
And of course, a large chunk of the 300 million are people whose parents had large families in the 1950s and who themselves haven't had any children.
The people who whine and cry most about Mexicans "stealing" jobs and the loss of America's "ethnic balance" are often people who haven't replaced themselves.
Read Mark Steyn’s Book, “Ameica Alone.” it has the best analysis I have seen of the population issue. At the moment, Americans are reproducing at exactly the rate necessary to maintain the native population—2.1 births per woman on average.
In many places in Europe, the number has fallen below status quo. However, the Muslim population in Europe is obliging and has birth rates around 3.5 or 3.6. There will come a tipping point when they become the majority. For all the women who live and die by the issue of “choice” they may very well spend the last years of their lives under Sharial law.
Incredible irony.