a reply from china,
at that time, when the situation of less people,less economic scale is come in, on the whole,the growth and margin of listed corporation will still better than average of general industry sector.
there will be opportunites very different from present time. new story will attract new money. old money need to learn or loss,because what i can predict is those growth opportunities may be priced very very high at that time.
but p/e ratio is technically unpredictable when your country's FED and treasury tend to intervene the finance market even more often when GDP growth rate loss impetus by less population
and the innovation impacts is also unpredictable, that have influence on P/E ratio