> Except that savings for tomorrow would probably end up in the stock market.

For far lower returns. With reduced demand, there's not much for that extra money to do. To the extent investment drives growth it's when it goes into innovation (R&D) or if businesses have demand but are capital constrained (and I suspect even that's more like speeding up than creating growth, exactly—you just get 5% growth now instead of 2.5% over two years, or whatever). Sure maybe you could spend it on advertising and marketing but all that can do is get us back to "people spend too much".

How does one draw the line between necessary marketing/sales expenses and unnecessary ones? Even some of the most "innovative" companies like Apple spend billions on advertising. I don't have an MBA but it seems pretty much impossible to sell new products without an advertising budget.

Right but if the premise is “there will be lots of investment because people are spending less and saving more” then all that invested money can’t go into marketing or advertising without getting right back to a low-savings society, unless that spending is ineffective. So that leaves R&D I guess since there’s not much else for that extra money to do. Plus lower returns on equities.

As the stock market becomes "overvalued" some investors pull their money out and invest in other "undervalued" assets. Real estate has been a major asset of choice over the past decade. Perhaps that will continue or some new asset will come into vogue.

Inflation doesn’t “kill”. You lose a percent or two a year. Put the savings in a no-penalty CD for emergencies and even that gets better.