Pro-natalists believe that falling birthrates are priming countries for economic collapse. This view is probably wrong, but in any case, the obvious response is expanded immigration. 

Using data from 38 OECD countries, new research finds that 

growth in native-born populations has slowed substantially, while immigration has increased significantly. … [This] immigration has been associated with stronger economic performance.

as immigration increased, businesses and economies invested more in capital, such as equipment, technology, and other resources that enhance workers’ output. Immigration was also associated with increases in workforce skills and broader improvements in productivity.

The study also found that 

high-skilled immigrants appear to make particularly strong contributions to productivity and investment. Policies that facilitate attracting and retaining skilled workers may therefore help countries address demographic declines and support economic growth. 

Current policymakers should consider these results before restricting high-skilled immigration.

Cross-posted from Substack.