Having written at length about the deterministic relationship between growth and demographics, this site (Japan Spike) provides several very photogenic examples of the results of de-urbanization / population collapse (see this graph first). Demographics are important. They even affect stock market returns (more accurately, certain demographic indicators are good proxies for other factors that affect general market performance).

The US, on the other hand, is in a very good long-term position relative to other developed nations; and stacks up reasonably well against (currently) emerging markets, in terms of demographic trends. Out of curiosity I constructed a dependency ratio projection for several countries (dependency ratio defined as [(Pop0-14+Pop65+)/Pop15-65], and is a general measure of how many resources must be used to take care of useless old people (higher ratio is worse, at least in terms of national economic health. There are probably other spillovers, as old people make great neighbors and Chess partners).

As usual, caveat projector future impossible to predict etc etc.:

This is of course assuming that there’s no world-altering singularity in 2030. It would be nice but I certainly wouldn’t bet on it. Data from US Census Bureau International Database, excel file here.