Recently, the New York Times reported on the need for higher birthrates in China and Europe. There is an unspoken assumption looming behind Steven Erlanger’s article, which rings alarm bells about “aging populations and not enough babies.” He assumes that healthy demographics require replacement-level fertility. But is it true? Even at current birthrates, we’ll fill our world with more than eleven billion people by 2100. Does anyone want their children to live in a world like that, given that our current population of 7.2 billion is enough to degrade our atmosphere, acidify our oceans, change our climate, and cause the mass extinction of other species? Demographics is about values as much as numbers. Assuming the need for replacement-level fertility values traditional growth economics over a cleaner, safer, and healthier future – for us and for our children.