Whether something is "economical" or not is relative to the
preferences of the decision-maker. And the preferences of a single
person like ourselves can effectively be a weighted average of many
different preferences, as if we were composed of parts with many
different preferences.
So to make your scenario plausible, you need a plausible process which
creates this massive convergence to a preference with almost no weight
on long-time-scale returns. One way to get convergence of preferences
is via evolutionary selection, but that process seems to select
exactly for the preferences you don't want in your scenario.
Robin Hanson hanson@hss.caltech.edu http://hss.caltech.edu/~hanson/