Auguste Walras, a French economist, tried to persuade his son, Leon Walras (b. 1834) to also become an economist, but Leon would not have a bar of it — he wanted to be a mining engineer!  After trying this (and several other careers, including one as a romance novelist) he returned to economics and went on to co-discover and develop the marginal utility theory and the notion of general equilibrium—both hugely important (if often mis-applied) concepts in economics still today.

If the world was in a general equilibrium state, then there would be no shortages or surpluses, and the price of everything (including the interest rate) would reflect the true value of both the marginal buyer and marginal seller.  Fortunately for us in business the world is not in such a state because if it were there would also be no opportunity for profit. 

The lesson? if you are seeking help towards profit-oriented business, then don’t use economic tools that assume the world is in any sort of equilibrium!  It isn’t!