I have been told that population aging is hardly the disaster certain natalists are making it to be: just look at how well Germany and Japan have handled it. Unfortunately, it is a rear-mirror view, reminiscent of the proverbial optimist falling off a skyscraper and saying, twenty floors down, “So far, so good.”
As people start having fewer children, the total dependency ratio (TDR) – the number of the people below and above the working age divided by the number of working-age residents – naturally goes down at first. Then it picks up again, as shrinkage in the young crowd slows but the the old-age cohort keeps on swelling. Germany (p. 26) and Japan (see UN data) have passed their historical TDR minimums and found themselves on an upward trend, less steep in Germany thanks to immigration.
An increase in fertility would help to slow down the TDR decline – assuming at least some immigration, almost to stop it. But such increases can’t be guaranteed even with the best thought-out pro-natalist policies.