In the Long Run We're All Ill-defined

Admittedly I'm no expert in details of modern macroeconomic theory, but one thing that has bothered me since the beginning of that course in college is the concept of the long and the short run.  They seem so varyingly and broadly defined to me as to be relatively useless.  To me this is exemplified in the oft-quoted evasion by the famous John Maynard Keynes, "In the long run, we are all dead."

The one important point I do recall about the subject is the admonition that correlation X and law Y apply only in the short run.  As well as I recall, this stipulation applied to every quantitative concept that we learned.

If one were to take the pragmatic position for central planning based on macroeconomic models, wouldn't one need to answer to a high degree of certainty this glaring issue?  Isn't the long-term the period we should be interested in for our future and that of our posterity?  Do we know the effects of today's policies on prosperity 5, 10 or 15 years down the line?  Is it mere coincidence that politicians, who are in office for a relatively short period in comparison to the length of a human life, seem serially uninterested in the long-term effects of their "scientifically" guided, short-term machinations?  If pharmaceutical companies relied only on science investigating the immediate effects and side effects of their drugs, would we not cry foul?  Would we not accuse them of confirmation bias?


It is fine by me if someone wishes to invest their wealth based on macroeconomic models.  It may be quite beneficial for them, and I wish them the best.   But, I will not consent to having mine taken to support such lofty and ill-defined goals.  Unfortunately, as a lowly citizen of these states I have no choice in the matter.