Wondering why government can't restart the sluggish economy? Well, one reason is that we are still paying the price for the greatest blunder in domestic policy since World War II. This occurred a half-century ago and helps explain today's policy paralysis. The story — largely unrecognized — is worth understanding.

Until the 1960s, Americans generally believed in low inflation and balanced budgets. President John Kennedy shared the consensus but was persuaded to change his mind. His economic advisers argued that, through deficit spending and modest increases in inflation, government could raise economic growth, lower unemployment and smooth business cycles.

None of this proved true; all of it led to grief.