What is Fiscal Cliff and why it is hurting US already?

Hugh Johnson: Fear of 'Fiscal Cliff' Hurting Economy Already

The fiscal cliff means uncertainity. And uncertainity spooks investors.  The fiscal and policies are being watched by investors. And when they are unclear as today, in US, being a period of Fiscal  Cliff... (Fiscal cliff is happenning because the tax perks expired are expiring, and nothing is certain as to their replacement)