Women will consider how a situation benefits them before deciding to have a child, and so in many developed nations, after the fertility rate declines to below 2.0, it continues to fall. Several Western European nations have slid to about 1.4.
婦女會考量對自己較有利的情況決定生育子女數，許多先進國因此生育率都在低過二人以後，仍繼續下降，西歐不少國家就都下滑到一點四左右。