The U.S., until recently, bucked this trend, for two main reasons. The first is that we had very high fertility rates among Hispanic immigrants. The second is that we had very high teen pregnancy for a rich country. Both of these factors are now disappearing -- fertility has plummeted among Hispanics, and teen pregnancy is way down. So now we seem to be facing the same aging issue that is bedeviling the rest of the developed world. It's worth noting that, since the 2007-09 recession, the fertility rates of rich countries such as France, Germany, Japan and the U.K. have actually risen, while that of the U.S. has fallen by more than 11 percent.