“The bad economist sees only what immediately strikes the eye; the good economist also looks beyond. The bad economist sees only the direct consequences of a proposed course; the good economist looks also at the longer and indirect consequences. The bad economist sees only what the effect of a given policy has been or will be on one particular group; the good economist inquires also what the effect of the policy will be on all groups.

The distinction may seem obvious. The precaution of looking for all the consequences of a given policy to everyone may seem elementary. Doesn’t everybody know, in his personal life, that there are all sorts of indulgences delightful at the moment but disastrous in the end? Doesn’t every little boy know that if he eats enough candy he will get sick? Doesn’t the fellow who gets drunk know that he will wake up next morning with a ghastly stomach and a horrible head? Doesn’t the dipsomaniac know that he is ruining his liver and shortening his life? Doesn’t the Don Juan know that he is letting himself in for every sort of risk, from blackmail to disease? Finally, to bring it to the economic though still personal realm, do not the idler and the spendthrift know, even in the midst of their glorious fling, that they are heading for a future of debt and poverty?

Yet when we enter the field of public economics, these elementary truths are ignored. There are men regarded today as brilliant economists, who deprecate saving and recommend squandering on a national scale as the way of economic salvation; and when anyone points to what the consequences of these policies will be in the long run, they reply flippantly, as might the prodigal son of a warning father: “In the long run we are all dead.” And such shallow wisecracks pass as devastating epigrams and the ripest wisdom.”

— Henry Hazlitt. Economic In One Lesson