Should rich countries try to get their citizens to have more children? Social conservatives generally say "yes." Centrists often tentatively agree, worrying that the financial burden of paying for aging populations will be intolerable for a shrinking base of young workers. Liberals often counter that more people in rich countries would just put pressure on the environment, and that population problems are better solved by higher immigration.
The truth is, the right answer to this question probably varies from country to country. In the United States, boosting fertility isn't a big priority. The U.S. has a total fertility rate of 1.8 children per woman, which is reasonably close to the replacement rate of 2.1 — i.e., the rate that leads to long-term population stability. Also, the U.S. tends to be welcoming to immigrants and has been able to attract large numbers of the skilled immigrants who contribute most to fiscal and financial sustainability.
But for rich countries in Europe and East Asia, the picture isn't so rosy. These countries have historically defined their national identity less in terms of universal ideals and more in terms of shared ancestry and ethnicity — as much as liberals would like to change that fact, it means that countries such as Germany, Japan and South Korea probably can't import enough people to cancel out aging without risking a xenophobic backlash.