> Does anyone have an intelligent strategy for investing in a world with low birth rates and an aging population?

If you read the latest Charles Goodhart's book ageing population would bring period of permanent high inflation. And during high inflation periods trend following (macro) strategies work well [I don't have a link to the paper at the moment]... So this should be rather simple...

Japan seems to be an exception to the rule, there are probably other factors that resulted in deflation during falling population era [I am fan of Richard C. Koo here - 2].

However it is not established yet - there is active discussion going on the topic - falling populations vs inflation/deflation. It is quite interesting actually.

Try Dimitri Kofinas's discussion with Charles Goodhart in this podcast [3] if you can spare an hour...

[1] https://www.amazon.com/Great-Demographic-Reversal-Societies-...

[2] https://www.amazon.com/Holy-Grail-Macroeconomics-Lessons-Rec...

[3] https://hiddenforces.io/podcasts/charles-goodhart-demographi...