[tbw2]

The societal impacts I see long term from the ability and social permission to choose childlessness:
* both any biological factors and memes that encourage childlessness will be weeded out of the population in two generations, and we’re already half way there
* the religious who favor families may be a minority in the West now but will grow in numbers and as a percentage of society because the future belongs to those who show up; ideally, that isn’t due to foreign imports but domestic production

[Wallace T.]

Look at Israel and Jewish-American populations for examples. Orthodox and observant Jews have higher birth rates than do their secular and liberal counterparts. Furthermore, the latter are more likely to marry non-Jews and over time their descendants will lose their Jewish identity, becoming just a part of their genetic inheritance. Should the faithful, observant Jews maintain their tradition over several generations, they will become the dominant population by sheer numbers.

Other than the Amish and Mennonites, and to some extent the Mormons, the Christian world has not produced a large community that will preserve their cultural and religious inheritance.