Today's Times has an article about adoption in South Korea that discusses issues of child and family preferences. The article suggests that adoption has traditionally been stigmatized, resulting in many emigrant adoptees. Interestingly, the article almost in passing mentions an increasing premium placed on girls, a stark turnaround relative to other Confucian societies where male children are typically valued as caregivers.
As a share of population growth, adoption is currently quite small. Still, it will be interesting to see whether changing norms about adoption might significantly alter fertility.